JP7568906B2 - Cation removal device, cation removal method, and anion detection device - Google Patents

Description

The present invention relates to a cation removal device, a cation removal method, and an anion detection device.

In power plants that generate electricity using steam turbines, such as thermal power plants and nuclear power plants, high-temperature, high-pressure steam generated in a boiler is introduced into the steam turbine. The steam discharged from the steam turbine is condensed in a condenser to become water, which is then supplied to the boiler. Seawater is used as the cooling water used to condense the steam in the condenser of a power plant. Therefore, if a pinhole occurs in the condenser, seawater will mix with the water circulated between the boiler and the condenser (circulating water), and the concentration of salt in the circulating water will increase. In this way, pollutants that corrode the circulation system (piping) of the circulating water may accumulate in the circulating water. Corrosion of the circulation system may cause problems such as corrosion, thinning, and cracks in the piping of the circulation system. Therefore, the quality of the circulating water is constantly monitored.

One method for monitoring the quality of circulating water is to measure the electrical conductivity (or resistivity) of the circulating water (see, for example, Patent Document 1).

The method described in Patent Document 1 detects contaminants contained in the circulating water by sampling a portion of the circulating water as sample water and observing the change in the electrical conductivity of the sample water (i.e., the quality of the circulating water is monitored). In this method, among the components contained in the sample water, components that affect the electrical conductivity of the sample water other than contaminants are removed in advance before measuring the electrical conductivity of the sample water.

In order to suppress corrosion of the water circulation system, ammonia that makes the circulating water alkaline and hydrazine that reduces the oxygen concentration in the circulating water are added to the circulating water. In recent years, the use of hydrazine, which is carcinogenic, has been refrained from, and the amount of ammonia added to the circulating water instead has been increasing. That is, the circulating water always contains ammonia (ionized ammonium ion: NH ₄ ⁺ ) at a predetermined concentration or more. Even if seawater leaks in the condenser, the amount of seawater mixed into the circulating water is small, and the salinity concentration (i.e., the amount of pollutants) in the circulating water is sufficiently lower than the ammonia concentration. Therefore, when detecting seawater leakage in the condenser by a change in electrical conductivity, ammonia (i.e., NH ₄ ⁺ ) contained in the sample water is removed by a cation exchanger before measuring the electrical conductivity.

A cation exchanger typically comprises an anode and a cathode arranged opposite each other, an anode chamber in which the anode is arranged, a cathode chamber in which the cathode is arranged, and a cation exchange membrane that separates the anode chamber and the cathode chamber. Sample water is supplied to the anode chamber. Cations contained in the sample water are removed in the anode chamber and move to the cathode chamber via the cation exchange membrane. The cations that have moved to the anode chamber are discharged together with the water flowing through the cathode chamber.

When seawater is mixed into the sample water, the sample water contains components derived from seawater, such as NaCl and Na ₂ SO _4. These components are ionized in the sample water into cations such as Na ⁺ and anions such as Cl ^- and SO ₄ ^2- . As described above, when the sample water is treated by a cation exchanger, cations such as Na ⁺ are exchanged with H ⁺ together with NH ₄ ⁺ and are removed. As a result, the counter ions of anions such as Cl ^- and SO ₄ ^2- become H ⁺ . That is, the sample water becomes an aqueous solution of hydrochloric acid or sulfuric acid. The change in electrical conductivity of these aqueous solutions is larger than the change in electrical conductivity of the sample water before ion exchange. Therefore, the mixing of seawater can be detected with high sensitivity.

In recent years, energy-generating power sources such as solar power generation have become widespread, and power plants such as thermal power plants and nuclear power plants can be operated to change the amount of power generated frequently according to the amount of energy generated. In addition, chemical injection devices for boilers are improving day by day, and new water treatment technologies can be introduced to boilers. As a result, it is expected that the concentration (pH) of cations (NH ₄ ⁺ ) in circulating water in the future will fluctuate more greatly than it does now.

In conventional methods such as those described in Patent Document 1, the cation concentration in the treated water is assumed to hardly fluctuate in the process of removing cations. Therefore, the value of the current passed between the anode and cathode to remove cations (the voltage applied between the anode and cathode) is determined in advance to a value corresponding to the cation concentration. As a result, when the cation concentration in the sample water becomes high, the removal of cations becomes insufficient, and when the cation concentration becomes low, a large amount of bubbles (oxygen at the anode, hydrogen at the cathode) is generated. Thus, conventional methods cannot be applied to circulating water in which the cation concentration fluctuates greatly.

International Publication No. 2000/057165

The present invention aims to provide a cation removal device, a cation removal method, and an anion detection device that can be applied to circulating water in which the cation concentration fluctuates greatly.

The cation removal device of the present invention comprises an anode chamber to which sample water is supplied and which removes cations from the sample water, a cathode chamber which discharges cations that have migrated from the anode chamber, a cation exchange membrane which separates the anode chamber from the cathode chamber, an anode placed in the anode chamber, a cathode placed in the cathode chamber, a power supply connected to the anode and cathode and which applies a voltage between the anode and cathode, an acquisition unit which acquires measurement results of the cation concentration of the sample water and/or the physical properties of the sample water which vary depending on the cation concentration, and a signal generation unit which generates a control signal to control the operation of the power supply based on the measurement results acquired by the acquisition unit, and the power supply changes the voltage based on the control signal.

The present invention provides a cation removal device, a cation removal method, and an anion detection device that can be applied to circulating water in which the cation concentration fluctuates greatly.

1 is a schematic diagram showing an embodiment of an anion detection device according to the present invention; FIG. 2 is a schematic cross-sectional view of a cation exchanger provided in the cation removal device according to the present invention. FIG. 4 is a schematic diagram showing another embodiment of an anion detection device according to the present invention. FIG. 11 is a schematic diagram showing still another embodiment of an anion detection device according to the present invention. FIG. 4 is a schematic cross-sectional view of another cation exchanger provided in the cation removal device according to the present invention. FIG. 11 is a schematic diagram showing still another embodiment of an anion detection device according to the present invention.

Below, with reference to the drawings, we will explain the embodiments of the cation removal device (hereinafter referred to as "the removal device"), cation removal method (hereinafter referred to as "the method"), and anion detection device (hereinafter referred to as "the detection device") of the present invention. In each figure, the same members and elements are given the same reference numerals, and duplicate explanations will be omitted.

In each of the embodiments described below, the detection device is incorporated into a boiler sampling device installed in a power plant, and the boiler water treated by the boiler sampling device (treated boiler water) is supplied to the detection device as sample water. In other words, the treated boiler water is an example of sample water in the present invention.

"Boiler water" is, for example, water that circulates through a circulation system between a boiler installed in a power plant and a condenser that condenses the steam from the boiler used in the power plant into water.

●Anion detector (1)●
Configuration of the Anion Detector (1) First, an embodiment (first embodiment) of the present detector will be described.

FIG. 1 is a schematic diagram showing an embodiment of the present detection device.
The figure shows that the detection device 1 is connected to a pipe L of a boiler sampling device 100. The figure also shows that an output from a pH meter 101 that measures the pH of the treated boiler water flowing through the pipe L is input to the detection device 1.

The boiler sampling device 100 acquires, cools, and depressurizes a portion of the circulating water to produce treated boiler water (sample water) with a temperature and pressure suitable for detecting anions using the detection device 1. The pH meter 101 is a measuring instrument in the present invention.

This detection device 1 removes cations contained in the sample water and detects anions contained in the sample water from which the cations have been removed. This detection device 1 comprises this removal device 2 and an electrical conductivity meter C11.

"Cations" include, for example, cations ( _NH4 ⁺ , _N2H5 ⁺ ) derived from water quality conditioners (ammonia, _hydrazine ) added to the boiler water, and cations (Na ⁺ , ^Ca2+ ) derived from impurities that may be mixed into the boiler water (for example, seawater mixed into the boiler water).

The "anions" are, for example, anions (Cl ^- , SO ₄ ^2- ) derived from impurities that may be mixed into the boiler water.

This removal device 2 removes cations contained in sample water. This removal device 2 includes a cation exchanger 10, a control unit 30, a signal unit 40, pipes L11, L12, L13, L14, L15, and L16, valves V11 and V12, a filter F, flow meters FL11 and FL12, and a vent B11.

Figure 2 is a schematic cross-sectional view of the cation exchanger 10.

The cation exchanger 10 removes cations contained in the sample water. The cation exchanger 10 includes a housing 11, an anode chamber 12, a cathode chamber 13, a cation exchange membrane 14, an anode 15, and a cathode 16.

The housing 11 contains the anode 15 and the cathode 16, and together with the cation exchange membrane 14 forms the anode chamber 12 and the cathode chamber 13. The housing 11 is made of a synthetic resin such as polypropylene. The housing 11 has a first half 11a and a second half 11b.

The first half 11a is box-shaped with a rectangular recess that forms the anode chamber 12. The first half 11a has an anode chamber inlet 12a, which is an inlet for sample water supplied to the anode chamber 12, and an anode chamber outlet 12b, which is an outlet for sample water (treated water, described below) discharged from the anode chamber 12.

The second half 11b is box-shaped with a rectangular recess that forms the cathode chamber 13. The second half 11b has a cathode chamber inlet 13a, which is an inlet for cathode water supplied to the cathode chamber 13, and a cathode chamber outlet 13b, which is an outlet for cathode water discharged from the cathode chamber 13. The shape of the second half 11b is the same as the shape of the first half 11a.

"Cathode water" is water that is supplied to the cathode chamber 13 and expels cations that have migrated from the anode chamber 12 from the cathode chamber 13. In this embodiment, a portion of the sample water is supplied as the cathode water.

The anode chamber 12 is an area that houses the anode 15 and removes cations from the sample water.

The cathode chamber 13 is an area that houses the cathode 16 and discharges cations that have migrated from the anode chamber 12 via the cathode water.

The cation exchange membrane 14 is sandwiched between the first half 11a and the second half 11b, and forms the anode chamber 12 together with the first half 11a, and forms the cathode chamber 13 together with the second half 11b. In other words, the cation exchange membrane 14 separates the anode chamber 12 from the cathode chamber 13. The cation exchange membrane 14 is a known membrane-shaped cation exchange resin (for example, a resin in which sulfonic acid groups are introduced into a styrene-divinylbenzene copolymer).

The anode 15 and the cathode 16 are electrodes that pass the current required for ion exchange through the sample water. The anode 15 is placed in the anode chamber 12. The anode 15 is a known electrode, such as a platinum-coated titanium plate. The cathode 16 is placed in the cathode chamber 13. The cathode 16 is a known electrode, such as a stainless steel plate.

The area of each of the anode 15 and the cathode 16 is set, for example, according to the current density between the anode 15 and the cathode 16 required for ion exchange in the cation exchanger 10. The anode 15 is disposed in the anode chamber 12, and the cathode 16 is disposed in the cathode chamber 13 so as to face the anode 15. The distance between the anode 15 and the cathode 16 is set, for example, according to the potential gradient between the anode 15 and the cathode 16 required for ion exchange in the cation exchanger 10.

In the anode chamber 12, a known cation exchange resin (not shown) is filled between the cation exchange membrane 14 and the anode 15. In the cathode chamber 13, a known cation exchange resin (not shown) is filled between the cation exchange membrane 14 and the cathode 16. The filling rate of each cation exchange resin is set, for example, by the respective flow paths of the sample water and the cathode water, and the rate of movement of cations.

Return to Figure 1.
The control unit 30 controls the overall operation of the detection device 1. The control unit 30 includes a connection section 31, a control section 32, a storage section 33, and a power supply section .

The connection unit 31 is an interface that is electrically connected to the signal unit 40.

The control unit 32 manages and adjusts the sample water and cathode water based on, for example, various settings stored in the memory unit 33 and information from the flow meters FL11 and FL12 and a thermometer (not shown). The control unit 32 is composed of, for example, a processor such as a CPU (Central Processing Unit) and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

The memory unit 33 stores information necessary for the operation of the control unit 30. The memory unit 33 is, for example, a memory such as a RAM or a Secure Digital (SD) memory card.

The power supply unit 34 is connected to the anode 15 and the cathode 16, and applies a voltage required for ion exchange between the anode 15 and the cathode 16 (a voltage that causes a current of a target current value, described below, to flow between the anode 15 and the cathode 16). The power supply unit 34 is, for example, a known DC power supply unit. The power supply unit 34 is the power supply in the present invention. The power supply unit 34 includes a control board (not shown) that controls the voltage (current) output by the power supply unit 34.

The signal unit 40 acquires the measurement result of the pH meter 101 and generates a control signal. The signal unit 40 includes a connection unit 41, a memory unit 42, an acquisition unit 43, and a signal generation unit 44.

The connection unit 41 is an interface connected to the pH meter 101 and the control unit 30.

The memory unit 42 stores the measurement results of the pH meter. The memory unit 42 is, for example, a memory such as a RAM or an SD memory card.

The acquisition unit 43 acquires the measurement results of the physical properties of the sample water that vary depending on the cation concentration in the sample water. The specific operation of the acquisition unit 43 will be described later.

The "physical property value" is a value that indicates the magnitude of a property of a substance (sample water), such as the pH, electrical conductivity, or resistivity of the sample water. In this embodiment, the physical property value is the pH value of the sample water measured by the pH meter 101.

The signal generating unit 44 generates a control signal based on the measurement results acquired by the acquiring unit 43. The specific operation of the signal generating unit 44 and the control signal will be described later.

The acquisition unit 43 and the signal generation unit 44 are composed of, for example, a processor such as a CPU and memories such as a ROM and a RAM.

The electrical conductivity meter C11 measures the electrical conductivity of the treated water, which will be described later. The electrical conductivity meter C11 is, for example, a known electrical conductivity meter such as a flow cell type AC two-electrode type. The electrical conductivity meter C11 is the treated water measuring device of the present invention.

Pipe L11 connects valve V11, which is an inlet for sample water from pipe L, to flow meters FL11 and FL12. A filter F that removes foreign matter contained in the sample water is connected to pipe L11. A branch point P11 is disposed between valve V11 and filter F in pipe L11. Pipe L12 connects branch point P11 to a drain outlet (not shown). Valve V12, which is a safety valve, is connected to pipe L12. A branch point P12 is disposed downstream of filter F in pipe L11. Pipe L11 branches into pipes L13 and L14 downstream of branch point P12.

Pipe L13 is a pipe that connects branch point P12 and the anode chamber inlet 12a. A flow meter FL11 that adjusts the flow rate of the sample water supplied to the anode chamber inlet 12a is connected to pipe L13. Pipe L14 is a pipe that connects branch point P12 and the cathode chamber inlet 13a. A flow meter FL12 that adjusts the flow rate of the sample water (cathode water) supplied to the cathode chamber inlet 13a is connected to pipe L14.

Pipe L15 is a pipe that connects the anode chamber outlet 12b and a drain (not shown). An electrical conductivity meter C11 is connected to pipe L15. Pipe L16 is a pipe that connects the cathode chamber outlet 13b and a drain (not shown). A branch point P13 is disposed in pipe L16. A vent B11 that discharges gas contained in the cathode water in pipe L16 is connected to branch point P13.

Operation of the anion detection device (1) Next, the operation of the detection device 1 (removal device 2) will be described. The detection device 1 removes cations from a water sample using the removal device 2, measures the electrical conductivity of the water sample from which the cations have been removed (hereinafter referred to as "treated water"), and detects anions contained in the water sample from the change in electrical conductivity.

First, we will explain the method for removing cations contained in sample water using this removal device 2 (i.e., this method).

The sample water introduced into pipe L11 from valve V11 passes through filter F and is supplied to branch point P12, and from branch point P12 it is supplied to pipes L13 and L14. The sample water supplied to pipe L13 has its flow rate adjusted by flow meter FL11 and is supplied from the anode chamber inlet 12a to the anode chamber 12. On the other hand, the sample water supplied to pipe L14 has its flow rate adjusted by flow meter FL12 and is supplied as cathode water from the cathode chamber inlet 13a to the cathode chamber 13.

Next, the sample water supplied to the anode chamber 12 passes through the cation exchange resin in the anode chamber 12. At this time, the cations contained in the sample water are adsorbed by the cation exchange resin and removed. The sample water from which the cations have been removed is discharged as treated water from the anode chamber outlet 12b into pipe L15.

Next, the electrical conductivity meter C11 measures the electrical conductivity of the treated water in the pipe L15. The electrical conductivity meter C11 measures the electrical conductivity, for example, at all times.

Meanwhile, the cathode water supplied to the cathode chamber 13 passes through the cation exchange resin filled in the cathode chamber 13 and is discharged from the cathode chamber outlet 13b to the pipe L16.

In this way, the sample water and the cathode water are supplied to the cation exchanger 10. Next, the acquisition unit 43 acquires the pH of the sample water measured by the pH meter 101 of the boiler sampling device 100 as the measurement result via the connection unit 41. The measurement result (pH) is stored, for example, in the memory unit 42. Here, the pH meter 101 measures the pH, for example, constantly.

Next, the signal generating unit 44 generates a control signal based on the measurement results acquired by the acquiring unit 43. The control signal is transmitted to the control unit 32 of the control unit 30 via the connecting units 31 and 41.

In this embodiment, the "control signal" is a signal that determines the target current value (hereinafter referred to as the "target current value") of the current flowing between the anode 15 and the cathode 16. That is, the control signal is a signal that causes the power supply unit 34 to apply a voltage between the anode 15 and the cathode 16 so that a current of the target current value flows between the anode 15 and the cathode 16. In other words, the control signal is a signal that controls the operation of the power supply unit 34. Specifically, the control signal is, for example, a signal that converts the measurement result acquired by the acquisition unit 43 into a format that can be received by the control unit 30. The target current value is determined according to the cation concentration of the sample water, and is calculated by the control unit 32, for example. The target current value is, for example, a value greater than or equal to "0".

Next, the power supply unit 34 applies a voltage between the anode 15 and the cathode 16 so that a current of the target current value flows between the anode 15 and the cathode 16. In this way, the power supply unit 34 applies a voltage between the anode 15 and the cathode 16 according to the target current value calculated based on the control signal. In other words, the power supply unit 34 applies a voltage between the anode 15 and the cathode 16 based on the control signal.

When a voltage is applied between the anode 15 and the cathode 16, the cations adsorbed to the cation exchange resin in the anode chamber 12 pass through the cation exchange membrane 14 and repeatedly move to the adjacent cation exchange resin, and then move to the cation exchange resin in the cathode chamber 13. That is, the cation exchange resins in the anode chamber 12 and the cathode chamber 13 function as a medium for the movement of cations. As a result, the cations can move smoothly from the anode chamber 12 to the cathode chamber 13 without excessively increasing the voltage applied between the anode 15 and the cathode 16.

Meanwhile, the cations that have migrated into the cathode chamber 13 are mixed into the cathode water. The cathode water mixed with the cations that have migrated from the anode chamber 12 is sequentially discharged from the cathode chamber outlet 13b to pipe L16. Therefore, the amount of cations contained in the cathode water in the cathode chamber 13 is suppressed to a certain amount or less. As a result, the cations can move smoothly from the anode chamber 12 to the cathode chamber 13.

In this way, this detection device 1 (this removal device 2) can remove cations contained in the sample water.

Next, we will explain how to detect anions contained in sample water (treated water) using this detection device 1.

When the sample water contains components derived from impurities (NaCl, Na ₂ SO _4, etc.), the cation exchange resin in the anode chamber 12 adsorbs the cations derived from the impurities (Na ⁺ , Ca ^2+, etc.) and exchanges them with H ⁺ . That is, the treated water discharged to the pipe L15 contains anions derived from the impurities (Cl ^- , SO ₄ ^2- , etc.) and their counter ions, H ⁺ . As a result, the counter ions of anions such as Cl ^- and SO ₄ ^2- become H ⁺ . That is, the treated water becomes an aqueous solution containing hydrochloric acid and sulfuric acid. The change in electrical conductivity of these aqueous solutions is larger than the change in electrical conductivity of the sample water before ion exchange. Therefore, the present detection device 1 can detect the anions contained in the treated water by detecting the change (increase) in the electrical conductivity of the treated water. As a result, the present detection device 1 can estimate the concentration of anions contained in the treated water and detect the inclusion of seawater in the sample water (i.e., boiler water).

Next, the detection device 1 repeatedly acquires the pH (measurement result) of the treated water, generates a control signal based on the measurement result, and applies a voltage based on the control signal, thereby repeatedly removing cations contained in the sample water and measuring the electrical conductivity (detecting anions). As a result, the detection device 1 and the removal device 2 can each apply a voltage between the anode 15 and the cathode 16 based on the measurement result of the pH that varies depending on the concentration of cations (especially ammonium ions: NH ₄ ⁺ ) contained in the sample water, so that a current of a target current value suitable for removing cations flows between the anode 15 and the cathode 16. That is, for example, when the pH (cation concentration) of the treated water is high, the control unit 32 increases the target current value based on the control signal, and the power supply unit 34 increases the voltage based on the target current value. On the other hand, when the pH (cation concentration) of the treated water is low, the control unit 32 reduces the target current value based on the control signal, and the power supply unit 34 reduces the voltage based on the target current value. In other words, the power supply unit 34 changes the voltage applied between the anode 15 and the cathode 16 based on the control signal.

● Summary (1)
According to the embodiment described above, the signal generating unit 44 generates a control signal based on the measurement result of the pH of the sample water. The power supply unit 34 changes the voltage applied between the anode 15 and the cathode 16 based on the control signal. That is, the present detection device 1 and the present removal device 2 each control the voltage applied between the anode 15 and the cathode 16 based on the measurement result of the pH of the sample water so that a current of a target current value flows between the anode 15 and the cathode 16. As a result, the present detection device 1 and the present removal device 2 can each apply a voltage appropriate for removing cations to a sample water whose cation concentration varies greatly. Therefore, the present detection device 1 can appropriately detect anions contained in a sample water whose cation concentration varies greatly. That is, the present detection device 1 and the present removal device 2 can each be applied to a sample water (circulating water) whose cation concentration varies greatly.

●Anion detector (2)●
Next, another embodiment (second embodiment) of the present detection device will be described, focusing on the differences from the first embodiment described above. The anion detection device of the second embodiment differs from the anion detection device of the first embodiment in that treated water is used as cathode water.

Configuration of the Anion Detector (2) FIG. 3 is a schematic diagram showing another embodiment of the present detector.

This detection device 1A removes cations contained in the sample water and detects anions contained in the sample water from which the cations have been removed.

The detection device 1A includes a cation exchanger 10, a control unit 30, a signal unit 40, an electrical conductivity meter C11, pipes L11A, L12, L15A, and L16, valves V11 and V12, a filter F, a flow meter FL11, and a vent B11. In this embodiment, the detection device 1A also functions as the removal device 2A.

Pipe L11A connects valve V11 and anode chamber inlet 12a. Filter F is connected upstream of pipe L11A, and flow meter FL11 is connected downstream of filter F. Pipe L15A connects anode chamber outlet 12b and cathode chamber inlet 13a. That is, treated water discharged from anode chamber outlet 12b is supplied to cathode chamber 13 from cathode chamber inlet 13a as cathode water. Electrical conductivity meter C11 is connected to pipe L15A.

Operation of the anion detection device (2) Next, the operation of the detection device 1A (removal device 2A) will be described. The detection device 1A (removal device 2A) removes cations from a water sample, measures the electrical conductivity of the water sample (treated water) from which the cations have been removed, and detects anions contained in the water sample.

The sample water introduced into the pipe L11A from the valve V11 passes through the filter F, the flow rate is adjusted by the flow meter FL11, and the water is supplied to the anode chamber 12 from the anode chamber inlet 12a.

The sample water supplied to the anode chamber 12 then passes through the cation exchange resin in the anode chamber 12. At this time, the cations contained in the sample water are adsorbed by the cation exchange resin. In other words, the cations contained in the sample water are removed. The sample water from which the cations have been removed is discharged as treated water from the anode chamber outlet 12b into pipe L15A.

Next, the electrical conductivity meter C11 measures the electrical conductivity of the treated water in the pipe L15A in the same manner as in the measurement of the electrical conductivity of the treated water in the first embodiment.

The treated water in pipe L15A is then supplied to the cathode chamber 13 from the cathode chamber inlet 13a. The cathode water supplied to the cathode chamber 13 passes through the cation exchange resin filled in the cathode chamber 13 and is discharged from the cathode chamber outlet 13b to pipe L16.

In this manner, the sample water and the cathode water are supplied to the cation exchanger 10. Next, like the detection device 1 of the first embodiment, the detection device 1A repeatedly acquires the pH (measurement result) of the treated water, generates a control signal based on the measurement result, and applies a voltage based on the control signal, thereby repeatedly removing cations contained in the sample water and measuring electrical conductivity (detecting anions). As a result, like the detection device 1 and the removal device 2 of the first embodiment, the detection device 1A and the removal device 2A can each control the voltage applied between the anode 15 and the cathode 16 so that a current of a target current value appropriate for removing cations flows between the anode 15 and the cathode 16.

Here, as described above, the treated water discharged from the anode chamber outlet 12b to the pipe L15A is supplied to the cathode chamber 13 from the cathode chamber inlet 13a. Also, as described above, the cation concentration contained in the treated water (cathode water) supplied to the cathode chamber 13 is lower than the cation concentration contained in the sample water supplied to the anode chamber 12. Therefore, even if cations move from the anode chamber 12 to the cathode chamber 13, the cation concentration contained in the cathode water does not become higher than the cation concentration contained in the sample water supplied to the anode chamber 12. As a result, the cations can move smoothly from the anode chamber 12 to the cathode chamber 13. Also, in this detection device 1A, the treated water is used as the cathode water. Therefore, the amount of treated water required for this detection device 1A is half that of this detection device 1 of the first embodiment.

● Summary (2)
According to the embodiment described above, the detection device 1A and the removal device 2A can each apply a voltage appropriate for removing cations to a water sample whose cation concentration varies greatly, similar to the detection device 1 and the removal device 2 of the first embodiment. Therefore, the detection device 1A can appropriately detect anions contained in a water sample whose cation concentration varies greatly. In other words, the detection device 1A and the removal device 2A can each be applied to a water sample (circulating water) whose cation concentration varies greatly.

●Anion detector (3)●
Next, a third embodiment of the present detection device will be described, focusing on the differences from the first embodiment described above. The anion detection device of the third embodiment differs from the anion detection device of the first embodiment in that it includes two cation exchangers.

Configuration of the Anion Detector (3) FIG. 4 is a schematic diagram showing still another embodiment of the present detector.

This detection device 1B removes cations contained in the sample water and detects anions contained in the sample water from which the cations have been removed. This detection device 1B comprises this removal device 2B and an electrical conductivity meter C11.

This removal device 2B removes cations contained in the sample water. This removal device 2B includes cation exchangers 10 and 20, a control unit 30B, a signal unit 40B, pipes L11B, L12, L13, L14, L15B, L16, L17, L18, and L19, valves V11 and V12, a filter F, flow meters FL11, FL12, and FL13, and vents B11 and B12.

Figure 5 is a schematic cross-sectional view of the cation exchanger 20.

The cation exchanger 20 removes cations contained (remaining) in the treated water from which cations have been removed by the cation exchanger 10 (hereinafter referred to as "deionized water"). The cation exchanger 20 includes a housing 21, an anode chamber 22, a cathode chamber 23, a cation exchange membrane 24, an anode 25, and a cathode 26.

The housing 21 contains the anode 25 and the cathode 26, and together with the cation exchange membrane 24 forms the anode chamber 22 and the cathode chamber 23. The housing 21 is made of a synthetic resin such as polypropylene. The housing 21 has a first half 21a and a second half 21b.

The first half 21a is box-shaped with a rectangular recess that forms the anode chamber 22. The first half 21a has an anode chamber inlet 22a, which is an inlet for deionized water supplied to the anode chamber 22, and an anode chamber outlet 22b, which is an outlet for deionized water (treated water) discharged from the anode chamber 22.

The second half 21b is box-shaped with a rectangular recess that forms the cathode chamber 23. The first half 21a has a cathode chamber inlet 23a, which is an inlet for the second cathode water supplied to the cathode chamber 23, and a cathode chamber outlet 23b, which is an outlet for the second cathode water discharged from the cathode chamber 23. The shape of the second half 21b is the same as the shape of the first half 21a.

The "second cathode water" is water that is supplied to the cathode chamber 23 and expels the cations that have migrated from the anode chamber 22 from the cathode chamber 23. In this embodiment, a portion of the sample water is supplied as the second cathode water.

The anode chamber 22 is an area that houses the anode 25 and removes cations from the deionized water. The anode chamber 22 is the second anode chamber in the present invention.

The cathode chamber 23 is an area that houses the cathode 26 and discharges the cations that have migrated from the anode chamber 22 via the second cathode water. The cathode chamber 23 is the second cathode chamber in the present invention.

The cation exchange membrane 24 is sandwiched between the first half 21a and the second half 21b, and forms the anode chamber 22 together with the first half 21a, and forms the cathode chamber 23 together with the second half 21b. That is, the cation exchange membrane 24 separates the anode chamber 22 from the cathode chamber 23. The cation exchange membrane 24 is a known membrane-shaped cation exchange resin (for example, a resin in which sulfonic acid groups are introduced into a styrene-divinylbenzene copolymer). The cation exchange membrane 24 is the second cation exchange membrane of the present invention.

The anode 25 and the cathode 26 are electrodes that pass the current required for ion exchange through the deionized water. The anode 25 is disposed in the anode chamber 22. The anode 25 is a known electrode, such as a platinum-coated titanium plate. The cathode 26 is disposed in the cathode chamber 23. The cathode 26 is a known electrode, such as a stainless steel plate. The anode 25 is the second anode in the present invention, and the cathode 26 is the second cathode in the present invention.

The area of each of the anode 25 and the cathode 26 is set, for example, according to the current density between the anode 25 and the cathode 26 required for ion exchange in the cation exchanger 20. The anode 25 is disposed in the anode chamber 22, and the cathode 26 is disposed in the cathode chamber 23 so as to face the anode 25. The distance between the anode 25 and the cathode 26 is set, for example, according to the potential gradient between the anode 25 and the cathode 26 required for ion exchange in the cation exchanger 20.

In the anode chamber 22, a known cation exchange resin (not shown) is filled between the cation exchange membrane 24 and the anode 25. In the cathode chamber 23, a known cation exchange resin (not shown) is filled between the cation exchange membrane 24 and the cathode 26. The filling rate of each cation exchange resin is set, for example, depending on the respective flow paths of the deionized water and the second cathode water, and the degree of movement of cations.

Return to Figure 4.
The control unit 30B controls the overall operation of the detection device 1 B. The control unit 30B includes a connection section 31B, a control section 32B, a storage section 33, and a power supply section 34B.

The connection part 31B is an interface that is electrically connected to the signal unit 40B.

The control unit 32B manages and adjusts the sample water and cathode water based on, for example, various settings stored in the memory unit 33 and information from the flow meters FL11, FL12, and FL13 and a thermometer (not shown). The control unit 32B is composed of, for example, a processor such as a CPU and memories such as a ROM and a RAM.

The power supply unit 34B is connected to the anode 15 and the cathode 16, and applies a voltage required for ion exchange (a first voltage described later) between the anode 15 and the cathode 16. The power supply unit 34B is also connected to the anode 25 and the cathode 26, and applies a voltage required for ion exchange (a second voltage described later) between the anode 25 and the cathode 26. The power supply unit 34B is, for example, a known DC power supply unit. The power supply unit 34B is the power supply in the present invention. The power supply unit 34B includes a control board (not shown) that controls the voltage (current) output by the power supply unit 34B.

The signal unit 40B acquires the measurement result of the pH meter 101 and generates a control signal. The signal unit 40B includes a connection unit 41B, a memory unit 42, an acquisition unit 43, and a signal generation unit 44B.

The connection part 41B is an interface connected to the pH meter 101 and the control unit 30B.

The signal generating unit 44B generates a control signal based on the measurement results acquired by the acquiring unit 43. The signal generating unit 44B is configured, for example, with a processor such as a CPU shared with the acquiring unit 43, and memories such as a ROM and a RAM. The specific operation of the signal generating unit 44B will be described later.

Pipe L11B connects valve V11 and flow meters FL11-FL13. Filter F is connected to pipe L11B. Branch point P11 is located in pipe L11B between valve V11 and filter F. Branch point P12B is located in pipe L11B downstream of filter F. Pipe L11B branches into pipe L13, pipe L14, and pipe L17 downstream of branch point P12B.

Pipe L15B is a pipe that connects the anode chamber outlet 12b and the anode chamber inlet 22a. Pipe L17 is a pipe that connects the branch point P12B and the cathode chamber inlet 23a. A flow meter FL13 that adjusts the flow rate of the sample water (second cathode water) supplied to the cathode chamber inlet 23a is connected to pipe L17.

Pipe L18 is a pipe that connects the anode chamber outlet 22b and a drain (not shown). An electrical conductivity meter C11 is connected to pipe L18. Pipe L19 is a pipe that connects the cathode chamber outlet 23b and a drain (not shown). A branch point P14 is disposed in pipe L19. A vent B12 that discharges gas contained in the second cathode water flowing in pipe L19 is connected to branch point P14.

Operation of the anion detector (3) Next, the operation of the detector 1B will be described. The detector 1B removes cations from the sample water using the removal device 2B, measures the electrical conductivity of the sample water (treated water) from which the cations have been removed by the removal device 2B using the electrical conductivity meter C11, and detects the anions contained in the sample water from the change in electrical conductivity.

The sample water introduced into pipe L11B from valve V11 passes through filter F and is supplied to branch point P12B, and is then supplied from branch point P12B to pipes L13, L14, and L17. The sample water supplied to pipe L13 is supplied to the anode chamber 12. The sample water supplied to pipe L14 is supplied to the cathode chamber 13 as cathode water. The sample water supplied to pipe L17 has its flow rate adjusted by flow meter FL13, and is supplied to the cathode chamber 23 from the cathode chamber inlet 23a as second cathode water.

Next, the sample water supplied to the anode chamber 12 passes through the cation exchange resin in the anode chamber 12. At this time, the cations contained in the sample water are adsorbed by the cation exchange resin and removed. The sample water from which the cations have been removed is discharged as deionized water from the anode chamber outlet 12b into pipe L15B.

The deionized water discharged into pipe L15B is then supplied to the anode chamber 22 from the anode chamber inlet 22a. The sample water supplied to the anode chamber 22 passes through the cation exchange resin in the anode chamber 22. At this time, the cations contained (residual) in the deionized water are adsorbed by the cation exchange resin and removed. The deionized water from which the cations have been removed is discharged as treated water from the anode chamber outlet 22b into pipe L18.

Next, the electrical conductivity meter C11 measures the electrical conductivity of the treated water flowing through the pipe L18 in the same manner as in the first embodiment.

Meanwhile, the second cathode water supplied to the cathode chamber 23 passes through the cation exchange resin filled in the cathode chamber 23 and is discharged from the cathode chamber outlet 23b to the pipe L19. At this time, the cations that have migrated from the anode chamber 22 are discharged together with the second cathode water to the pipe L19.

In this way, the sample water and the cathode water are supplied to the cation exchanger 10, and the deionized water and the second cathode water are supplied to the cation exchanger 20. Next, the acquisition unit 43 acquires the pH of the sample water as the measurement result via the connection unit 41B. The measurement result (pH) is stored, for example, in the memory unit 42.

Next, the signal generating unit 44B generates a control signal based on the measurement results acquired by the acquiring unit 43. The control signal is transmitted to the control unit 32B of the control unit 30B via the connecting units 31B and 41B.

In this embodiment, the "control signal" is a signal that determines the target current value (hereinafter referred to as the "first target current value") of the current (hereinafter referred to as the "first current") flowing between the anode 15 and the cathode 16, and the target current value (hereinafter referred to as the "second target current value") of the current (hereinafter referred to as the "second current") flowing between the anode 25 and the cathode 26. That is, in this embodiment, the control signal is a signal that applies a voltage (hereinafter referred to as the "first voltage") between the anode 15 and the cathode 16 so that a first current of the first target current value flows between the anode 15 and the cathode 16, and applies a voltage (hereinafter referred to as the "second voltage") between the anode 25 and the cathode 26 so that a second current of the second target current value flows between the anode 25 and the cathode 26. In other words, in this embodiment, the control signal is a signal that controls the operation of the power supply unit 34B. The first target current value and the second target current value are determined according to the cation concentration of the sample water, and are calculated, for example, by the control unit 32B. Here, the first target current value and the second target current value are, for example, values equal to or greater than "0."

Next, the power supply unit 34B applies a first voltage between the anode 15 and the cathode 16 so that a first current flows between the anode 15 and the cathode 16. At this time, the cations adsorbed to the cation exchange resin in the anode chamber 12 move to the cation exchange resin in the cathode chamber 13. Similarly, the power supply unit 34B applies a second voltage between the anode 25 and the cathode 26 so that a second current flows between the anode 25 and the cathode 26. At this time, the cations adsorbed to the cation exchange resin in the anode chamber 22 move to the cation exchange resin in the cathode chamber 23. In this way, the power supply unit 34B applies a first voltage between the anode 15 and the cathode 16 in accordance with the first target current value calculated based on the control signal, and applies a second voltage between the anode 25 and the cathode 26 in accordance with the second target current value calculated based on the control signal. In other words, the power supply unit 34B applies a first voltage between the anode 15 and the cathode 16, and applies a second voltage between the anode 25 and the cathode 26, based on the control signal.

Meanwhile, the cations that have migrated into the cathode chamber 13 are mixed into the cathode water and are sequentially discharged together with the cathode water from the cathode chamber outlet 13b to pipe L16. Similarly, the cations that have migrated into the cathode chamber 23 are mixed into the second cathode water and are sequentially discharged together with the second cathode water from the cathode chamber outlet 23b to pipe L19. As a result, the cations can move smoothly from the anode chamber 12 to the cathode chamber 13, and from the anode chamber 22 to the cathode chamber 23.

In this way, the detection device 1B (removal device 2B) can remove cations contained in the sample water.

Next, the detection device 1B repeatedly acquires the pH (measurement result) of the sample water, generates a control signal based on the measurement result, and applies the first voltage and the second voltage based on the control signal to remove cations contained in the sample water and detect anions. As a result, the detection device 1B and the removal device 2B can apply a first voltage between the anode 15 and the cathode 16 so that a current of a first target current value suitable for removing cations flows between the anode 15 and the cathode 16 based on the measurement result of the pH that varies depending on the concentration of cations (especially ammonium ions: NH ₄ ⁺ ) contained in the sample water, and can apply a second voltage between the anode 25 and the cathode 26 so that a current of a second target current value suitable for removing cations flows between the anode 25 and the cathode 26. That is, for example, when the pH (cation concentration) of the treated water is high, the control unit 32B increases the first target current value based on the control signal, and the power supply unit 34B increases the first voltage based on the first target current value. And/or, the control unit 32B increases the second target current value based on the control signal, and the power supply unit 34B increases the second voltage based on the second target current value. On the other hand, when the pH (cation concentration) of the treatment water is low, the control unit 32B decreases the second target current value based on the control signal, and the power supply unit 34B decreases the second voltage based on the second target current value. And/or, the control unit 32B decreases the first target current value based on the control signal, and the power supply unit 34B decreases the first voltage based on the first target current value. In other words, the power supply unit 34B changes the first voltage and the second voltage based on the control signal.

Here, when the pH (cation concentration) of the treated water is high, the control unit 32B and the power supply unit 34B may not change the first target current value and the first voltage, and may only increase the second target current value and the second voltage. When the pH (cation concentration) of the treated water is low, the control unit 32B and the power supply unit 34B may set the second target current value and the second voltage to "0" and remove cations only with the cation exchanger 10. When the pH (cation concentration) of the sample water is low, the control unit 32B and the power supply unit 34B may set the first target current value and the first voltage to "0" and remove cations only with the cation exchanger 20.

● Summary (3)
According to the embodiment described above, the signal generating unit 44B generates a control signal based on the measurement result of the pH of the sample water. The power supply unit 34B changes the first voltage applied between the anode 15 and the cathode 16 and changes the second voltage applied between the anode 25 and the cathode 26 based on the control signal. That is, based on the measurement result of the pH of the sample water, the present detection device 1B and the present removal device 2B each control the first voltage applied between the anode 15 and the cathode 16 so that a current of a first target current value flows between the anode 15 and the cathode 16, and control the second voltage applied between the anode 25 and the cathode 26 so that a current of a second target current value flows between the anode 25 and the cathode 26. As a result, the present detection device 1B and the present removal device 2B can each apply a first voltage and a second voltage appropriate for removing cations to a sample water in which the cation concentration varies greatly. Therefore, the present detection device 1B can appropriately detect anions contained in a sample water in which the cation concentration varies greatly. In other words, each of the detection device 1B and the removal device 2B can be applied to sample water (circulating water) in which the cation concentration varies greatly.

●Anion detector (4)●
Next, a fourth embodiment of the present detection device will be described, focusing on the differences from the third embodiment described above. The fourth embodiment of the anion detection device differs from the third embodiment in that it includes two electrical conductivity meters and that the operation of the power supply unit is controlled based on the measurement results of the electrical conductivity meters.

Configuration of the Anion Detector (4) FIG. 6 is a schematic diagram showing still another embodiment of the present detector.

This detection device 1C removes cations contained in the sample water and detects anions contained in the sample water from which the cations have been removed. This detection device 1C includes this removal device 2C and an electrical conductivity meter C11.

This removal device 2C removes cations contained in the sample water. This removal device 2C includes cation exchangers 10 and 20, a control unit 30C, a signal unit 40C, an electrical conductivity meter C12, pipes L11C, L12, L13, L14, L15C, L16, L17, L18, and L19, valves V11 and V12, a filter F, flow meters FL11, FL12, and FL13, and vents B11 and B12.

The control unit 30C controls the operation of the entire detection device 1C. The control unit 30C includes a connection unit 31C, a control unit 32C, a memory unit 33, and a power supply unit 34C.

The connection unit 31C is an interface that is electrically connected to the signal unit 40C.

The control unit 32C manages and adjusts the sample water and cathode water based on, for example, various settings stored in the memory unit 33 and information from the flow meters FL11, FL12, and FL13 and a thermometer (not shown). The control unit 32C is composed of, for example, a processor such as a CPU and memories such as a ROM and a RAM.

The configuration and operation of the power supply unit 34C are the same as those of the power supply unit 34B of the third embodiment. That is, the power supply unit 34C is connected to the anode 15 and the cathode 16, and applies a first voltage between the anode 15 and the cathode 16. The power supply unit 34C is also connected to the anode 25 and the cathode 26, and applies a second voltage between the anode 25 and the cathode 26. The power supply unit 34C is the power supply in the present invention.

The signal unit 40C acquires the measurement results of the electrical conductivity meter C12 and generates a control signal. The signal unit 40B includes a connection unit 41C, a memory unit 42C, an acquisition unit 43C, and a signal generation unit 44C.

The connection part 41C is an interface connected to the electrical conductivity meter C12 and the control unit 30C.

The memory unit 42C stores the measurement results of the electrical conductivity meter C12. The memory unit 42C is, for example, a memory such as a RAM or an SD memory card.

The acquisition unit 43C acquires the measurement results of the physical properties of the sample water that vary depending on the cation concentration in the sample water. The specific operation of the acquisition unit 43 will be described later.

The signal generating unit 44C generates a control signal based on the measurement results acquired by the acquiring unit 43C. The specific operation of the signal generating unit 44C will be described later.

The acquisition unit 43C and the signal generation unit 44C are composed of, for example, a processor such as a CPU and memory such as a ROM and a RAM.

The electrical conductivity meter C12 measures the electrical conductivity of deionized water. The electrical conductivity meter C12 is a known electrical conductivity meter, such as a flow cell type AC two-electrode type. The electrical conductivity meter C12 is a measuring instrument in the present invention.

Pipe L15C is a pipe that connects the anode chamber outlet 12b and the anode chamber inlet 22a. Pipe L15C is a connection path in the present invention. An electrical conductivity meter C12 is connected to pipe L15C.

Operation of the anion detector (4) Next, the operation of the detector 1C will be described. The detector 1C removes cations from a water sample using the removal device 2C, measures the electrical conductivity of the water sample (treated water) from which the cations have been removed by the removal device 2C using the electrical conductivity meter C11, and detects anions contained in the water sample.

The sample water introduced into pipe L11C from valve V11 is supplied to pipes L13, L14, and L17. The sample water supplied to pipe L13 is supplied to the anode chamber 12. The sample water supplied to pipe L14 is supplied to the cathode chamber 13 as cathode water. The sample water supplied to pipe L17 is supplied to the cathode chamber 23 from the cathode chamber inlet 23a as the second cathode water.

Next, the sample water supplied to the anode chamber 12 passes through the cation exchange resin in the anode chamber 12. At this time, the cations contained in the sample water are adsorbed by the cation exchange resin. The sample water from which the cations have been removed is discharged as deionized water from the anode chamber outlet 12b into the pipe L15C.

Next, the deionized water discharged into the pipe L15C is supplied to the anode chamber 22 from the anode chamber inlet 22a. At this time, the electrical conductivity meter C12 measures the electrical conductivity of the deionized water flowing through the pipe L15C. The electrical conductivity meter C12 measures the electrical conductivity, for example, all the time. The measured electrical conductivity is transmitted to the acquisition unit 43C via the connection unit 41C. That is, the acquisition unit 43C acquires the electrical conductivity of the deionized water measured by the electrical conductivity meter C12 as a measurement result via the connection unit 41C. The measurement result (electrical conductivity) is stored in, for example, the memory unit 42C .

Next, the deionized water supplied to the anode chamber 22 passes through the cation exchange resin in the anode chamber 22. At this time, the cations contained in the deionized water are adsorbed by the cation exchange resin. The deionized water from which the cations have been removed is discharged as treated water from the anode chamber outlet 22b into the pipe L18.

Next, the electrical conductivity meter C11 measures the electrical conductivity of the treated water flowing through the pipe L18 in the same manner as in the first embodiment.

Meanwhile, the second cathode water supplied to the cathode chamber 23 passes through the cation exchange resin filled in the cathode chamber 23 and is discharged from the cathode chamber outlet 23b to the pipe L19. At this time, the cations that have migrated from the anode chamber 22 are discharged together with the second cathode water to the pipe L19.

In this way, the sample water and the cathode water are supplied to the cation exchanger 10, and the deionized water and the second cathode water are supplied to the cation exchanger 20.

Next, the signal generating unit 44C generates a control signal based on the measurement results acquired by the acquiring unit 43C. The control signal is transmitted to the control unit 32C of the control unit 30C via the connecting units 31C and 41C.

The "control signal" is the same as the control signal in the second embodiment. That is, in this embodiment, the control signal is a signal that applies a first voltage between the anode 15 and the cathode 16 so that a first current of a first target current value flows between the anode 15 and the cathode 16, and applies a second voltage between the anode 25 and the cathode 26 so that a second current of a second target current value flows between the anode 25 and the cathode 26. In other words, in this embodiment, the control signal is a signal that controls the operation of the power supply unit 34C. The first target current value and the second target current value are each determined according to the cation concentration of the sample water, and are calculated by, for example, the control unit 32C. Here, the first target current value and the second target current value are each, for example, a value equal to or greater than "0".

Next, the power supply unit 34C applies a first voltage between the anode 15 and the cathode 16 so that a first current flows between the anode 15 and the cathode 16. At this time, the cations adsorbed to the cation exchange resin in the anode chamber 12 move to the cation exchange resin in the cathode chamber 13. Similarly, the power supply unit 34C applies a second voltage between the anode 25 and the cathode 26 so that a second current flows between the anode 25 and the cathode 26. At this time, the cations adsorbed to the cation exchange resin in the anode chamber 22 move to the cation exchange resin in the cathode chamber 23. In this way, the power supply unit 34C applies a first voltage between the anode 15 and the cathode 16 in accordance with the first target current value calculated based on the control signal, and applies a second voltage between the anode 25 and the cathode 26 in accordance with the second target current value calculated based on the control signal. In other words, the power supply unit 34C applies a first voltage between the anode 15 and the cathode 16, and applies a second voltage between the anode 25 and the cathode 26, based on the control signal.

Meanwhile, the cations that have migrated into the cathode chamber 13 are mixed into the cathode water and are sequentially discharged together with the cathode water from the cathode chamber outlet 13b to pipe L16. Similarly, the cations that have migrated into the cathode chamber 23 are mixed into the second cathode water and are sequentially discharged together with the second cathode water from the cathode chamber outlet 23b to pipe L19. As a result, the cations can move smoothly from the anode chamber 12 to the cathode chamber 13, and from the anode chamber 22 to the cathode chamber 23.

In this way, the detection device 1C (removal device 2C) can remove cations contained in the sample water.

Next, the detection device 1C repeatedly acquires the electrical conductivity of the deionized water (measurement result), generates a control signal based on the measurement result, and applies the first voltage and the second voltage based on the control signal, thereby repeatedly removing cations contained in the sample water and measuring the electrical conductivity (detecting anions). As a result, similar to the detection device 1B and the removal device 2B of the third embodiment, the detection device 1C and the removal device 2C can apply a _first voltage ^between the anode 15 and the cathode 16 so that a current of a first target current value suitable for removing cations flows between the anode 15 and the cathode 16, based on the measurement result of the electrical conductivity that varies depending on the concentration of cations (particularly, ammonium ions: NH 4 + ) contained in the deionized water, and can apply a second voltage between the anode 25 and the cathode 26 so that a current of a second target current value suitable for removing cations flows between the anode 25 and the cathode 26.

Here, when the electrical conductivity (cation concentration) of the deionized water is high, the control unit 32C and the power supply unit 34C may not change the first target current value and the first voltage, and may only increase the second target current value and the second voltage. When the electrical conductivity (cation concentration) of the deionized water is low, the control unit 32C and the power supply unit 34C may set the second target current value and the second voltage to "0" and remove cations only with the cation exchanger 10. When the electrical conductivity (cation concentration) of the deionized water is low, the control unit 32C and the power supply unit 34C may set the first target current value and the first voltage to "0" and remove cations only with the cation exchanger 20.

● Summary (4)
According to the embodiment described above, the signal generating unit 44C generates a control signal based on the measurement result of the electrical conductivity of the deionized water. The power supply unit 34C changes the first voltage applied between the anode 15 and the cathode 16 and changes the second voltage applied between the anode 25 and the cathode 26 based on the control signal. That is, the present detection device 1C and the present removal device 2C each control the first voltage applied between the anode 15 and the cathode 16 so that a current of a first target current value flows between the anode 15 and the cathode 16, and control the second voltage applied between the anode 25 and the cathode 26 so that a current of a second target current value flows between the anode 25 and the cathode 26, based on the measurement result of the electrical conductivity of the deionized water. As a result, the present detection device 1C and the present removal device 2C can each apply a first voltage and a second voltage appropriate for removing cations to a sample water in which the cation concentration varies greatly. Therefore, the present detection device 1C can appropriately detect anions contained in a sample water in which the cation concentration varies greatly. In other words, each of the detection device 1C and the removal device 2C can be applied to sample water (circulating water) in which the cation concentration varies greatly.

●Summary (Other)●
It should be noted that the time interval at which the pH meter of the present invention measures the pH of the sample water is not limited to those in the first to third embodiments. That is, for example, the pH meter may measure the pH at a predetermined time interval while the boiler sampling device is operating.

The time interval at which the electrical conductivity meter of the present invention measures the electrical conductivity of the treated water is not limited to the first to fourth embodiments. That is, for example, the electrical conductivity meter may measure the electrical conductivity at a predetermined time interval while the sample water and the cathode water are each supplied to the cation exchanger.

Furthermore, the signal generating unit in the present invention may generate a control signal each time the acquiring unit acquires a measurement result (pH, electrical conductivity), or may generate a control signal at a predetermined time interval.

Furthermore, in the first to fourth embodiments, the electrical conductivity meter of the present invention may measure resistivity instead of electrical conductivity.

Furthermore, in the first to fourth embodiments, the control unit of the present invention may determine the target current value, the first target current value, and the second target current value from the measurement results (pH or electrical conductivity) based on a table previously stored in the memory unit.

Furthermore, in the first to fourth embodiments, the control board of the power supply unit in the present invention may calculate the target current value, the first target current value, and the second target current value based on a control signal.

Furthermore, in the first to fourth embodiments, the acquisition unit of the present invention may acquire the cation concentration (e.g., ammonium ion concentration) contained in the sample water as the measurement result. In this case, for example, a measuring device for measuring the cation concentration is provided in the boiler sampling device or the present detection device.

Furthermore, in the first to fourth embodiments, the acquisition unit of the present invention may acquire the electrical conductivity of the treated water as the measurement result instead of the pH of the sample water.

Furthermore, in the third and fourth embodiments, the removal device may include three or more cation exchangers. In this case, the electrical conductivity meter is connected, for example, to a pipe connecting the anode chamber outlet and the anode chamber inlet of each cation exchanger.

Furthermore, the measurement results of the measuring device in the present invention may be output to the power supply unit via the connection unit, or directly without going through the connection unit. In this case, for example, a control board provided in the power supply unit may function as the acquisition unit and signal generation unit in the present invention.

Furthermore, in the first, third, and fourth embodiments, the removal device may be equipped with an electrical conductivity meter that measures the electrical conductivity of the treated water. That is, in the first, third, and fourth embodiments, the removal device may function as the detection device.

Furthermore, in the first to third embodiments, the acquisition unit of the present invention may acquire the electrical conductivity of the treated water as the measurement result instead of the pH of the treated boiler water (sample water).

Furthermore, in the first to fourth embodiments, the acquisition unit and the signal generation unit of the present invention may each be configured with a separate processor and memory.

Furthermore, in the first to fourth embodiments, the control unit and the signal unit of the present invention may be configured as a single unit.

1 Anion detection device 1A Anion detection device 1B Anion detection device 1C Anion detection device 2 Cation removal device 2A Cation removal device 2B Cation removal device 2C Cation removal device 12 Anode chamber 13 Cathode chamber 14 Cation exchange membrane 15 Anode 16 Cathode 22 Anode chamber (second anode chamber)
23 Cathode chamber (second cathode chamber)
24 Cation exchange membrane (second ion exchange membrane)
25 Anode (second anode)
26 Cathode (second cathode)
34 Power supply unit (power supply)
34B Power supply section (power supply)
34C power supply section (power supply)
43 Acquisition unit 43C Acquisition unit 44 Signal generation unit 44B Signal generation unit 44C Signal generation unit C11 Electrical conductivity meter (treated water measuring device)
C12 Electrical conductivity meter (measuring device)
L15C Piping (connection path)

Claims (5)

A cation removal device for removing cations contained in sample water, comprising:
an anode chamber to which the sample water is supplied and which removes the cations from the sample water;
a cathode chamber for discharging the cations that have migrated from the anode chamber;
a cation exchange membrane separating the anode chamber and the cathode chamber;
an anode disposed in the anode chamber;
A cathode disposed in the cathode chamber;
the sample water from which the cations have been removed from the anode chamber is supplied as deionized water, and a second anode chamber is configured to further remove the cations from the deionized water;
a second cathode chamber for discharging the cations that have migrated from the second anode chamber;
a second cation exchange membrane separating the second anode chamber and the second cathode chamber;
A second anode disposed in the second anode chamber;
A second cathode disposed in the second cathode chamber;
a power source connected to the anode and the cathode and applying a voltage between the anode and the cathode, and connected to the second anode and the second cathode and applying a second voltage between the second anode and the second cathode ;
an acquisition unit that acquires measurement results of the cation concentration of the sample water and/or a physical property value of the sample water that varies depending on the cation concentration;
a signal generating unit that generates a control signal for controlling an operation of the power supply based on the measurement result acquired by the acquiring unit;
and
The power supply changes at least one of the voltage and the second voltage based on the control signal.
A cation removal device characterized by: a connection path connecting the anode chamber and the second anode chamber;
a measuring device for measuring the electrical conductivity or resistivity of the deionized water in the connection path;
and
The acquisition unit acquires the electrical conductivity or the resistivity measured by the measuring device as the measurement result.
The cation removal device according to claim 1 . The acquisition unit acquires the pH, electrical conductivity, resistivity, or cation concentration of the sample water as the measurement result.
The cation removal device according to claim 1 . A cation removal device;
a treated water measuring device for measuring the electrical conductivity or resistivity of the treated water from which cations have been removed by the cation removal device;
and
The cation removal device is a cation removal device according to any one of claims 1 to 3 .
1. An anion detection device comprising: an anode chamber to which sample water is supplied and which removes cations from the sample water;
a cathode chamber for discharging the cations that have migrated from the anode chamber;
a cation exchange membrane separating the anode chamber and the cathode chamber;
an anode disposed in the anode chamber;
A cathode disposed in the cathode chamber;
the sample water from which the cations have been removed from the anode chamber is supplied as deionized water, and a second anode chamber is configured to further remove the cations from the deionized water;
a second cathode chamber for discharging the cations that have migrated from the second anode chamber;
a second cation exchange membrane separating the second anode chamber and the second cathode chamber;
A second anode disposed in the second anode chamber;
A second cathode disposed in the second cathode chamber;
a power source connected to the anode and the cathode and applying a voltage between the anode and the cathode, and connected to the second anode and the second cathode and applying a second voltage between the second anode and the second cathode ;
A cation removal method for removing the cations contained in the sample water, the method being performed by a cation removal device comprising:
a step of the cation removal device acquiring a measurement result of a cation concentration of the sample water or a physical property value of the sample water that varies depending on the cation concentration;
generating a control signal for controlling the operation of the power supply based on the measurement results obtained by the cation removal device;
the cation removal device varying at least one of the voltage and the second voltage based on the control signal;
Is there,
A method for removing cations.

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