JPH0439907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for simultaneously measuring electrical conductivity and acid conductivity of a liquid to be measured such as boiler cooling water.

<Conventional technology> Generally, the water used to rotate turbines used in thermal power generation and nuclear power generation is managed by measuring various parameters such as pH, electrical conductivity, acid conductivity, and hydrazine concentration. There is. especially,
The measurement of electrical conductivity and acid conductivity is important, and conventionally these measurements have been carried out as follows. That is, after first measuring the conductivity of the liquid to be measured using the first conductivity meter, the liquid to be measured is passed through an H ⁺ type cation exchange resin cylinder, and the acid conductivity of the liquid to be measured eluted from the cylinder is measured. I was trying to measure it with a second conductivity meter. In addition, the liquid to be measured is divided into two channels, one is led to the first conductivity meter to measure the conductivity of the liquid to be measured, and the other is passed through an H ⁺ type cation exchange resin cylinder. A second conductivity meter was used to measure the acid conductivity of the liquid to be measured eluted from the sample.
Note that acid conductivity is the conductivity measured with a conductivity meter after passing the liquid to be measured through an H ⁺ type cation exchange resin cylinder and exchanging the cations in the liquid with H ⁺ ions. It is also called cationic conductivity.

<Problems to be Solved by the Invention> However, in the conventional example described above, it was necessary to continuously pass the liquid to be measured through the H ⁺ type cation exchange resin cylinder in order to measure the acid conductivity. Therefore, the period for the ion exchange resin in the H ⁺ type cation exchange resin cylinder to cease to be H ⁺ type is short,
There was a drawback that the ion exchange resin had to be regenerated or replaced with a new one.

The present invention has been made in view of the drawbacks of the conventional examples, and its purpose is to minimize the amount of liquid to be measured, eliminate the need to replace the H ⁺ type cation exchange tube, etc. Another object of the present invention is to provide a method and apparatus capable of simultaneously measuring the conductivity and acid conductivity of a liquid to be measured.

<Means for Solving the Problems> A feature of the present invention that solves the above-mentioned problems is to provide a method and apparatus for simultaneously measuring the electrical conductivity and acid conductivity of a liquid to be measured. After that, the cations in the liquid to be measured are removed by ion exchange using a cation exchange membrane.
The purpose is to detect the acid conductivity of the liquid to be measured after exchanging it with H ⁺ ions.

<Example> Hereinafter, the present invention will be explained in detail using figures. FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention,
In the figure, 1a is a tank in which a mobile phase made of, for example, pure water is stored, 1d is a tank in which a scavenge liquid made of, for example, 15 mN H ₂ SO ₄ is stored, 1b, 1
c and 1e are tanks for storing waste liquid, 2a and 2b are pumps for feeding the mobile phase and scavenge liquid, respectively, and 3 is a tank with a certain internal volume (for example, 100 to 1000 μm) connected to the first to sixth connection ports 3a to 3f. 4 and 6 are conductivity meters, and 5 is a cation exchange membrane inside. Suppressor 7, which is divided into an inner chamber 5b and an outer chamber 5c by a tube 5a, in which the scavenging liquid containing H ⁺ ions flows, and the effluent from the conductivity meter 1 is guided into the inner chamber 5b. is a constant temperature chamber that houses the conductivity meters 4, 6 and the suppressor 5 and maintains them at a predetermined temperature (for example, 45° C.). The conductivity of the mobile phase is usually selected to be about 1/100 of the conductivity of the liquid to be measured.
Pure water is used as the mobile phase. In the embodiment of the present invention having such a configuration, when the pump 2a is driven, the mobile phase in the tank 1a is, for example, 2 ml/
min. (preferably a constant flow rate between 0.5 and 2.0 ml/min.), the pump 2a → the first sample sampling valve 3
and second connection ports 3a, 3b→conductivity meter 4→inner chamber 5b of suppressor 5→conductivity meter 6, and then through tank 1b
It flows in a channel that leads to. Further, when the pump 2b is driven, the scavenge liquid in the tank 1d is, for example, 2
At a flow rate of ml/min., pump 2b → suppressor 5
It flows through a flow path from the outer chamber 5c to the tank 1e. Furthermore,
The liquid to be measured is injected from the connection port 3e of the sample sampling valve 3, flows along the path of connection port 3f→metering tube 3g→connection port 3c→connection port 3d→tank 1c, and fills the inside of the metering tube 3g. When the sample collection valve 3 is turned on in this state, its internal flow path is switched from the solid line connection state to the broken line connection state. Therefore, the liquid to be measured in the measuring tube 3g is conveyed to the conductivity meter 4 by the mobile phase, and its conductivity is detected. The liquid to be measured flowing out of the conductivity meter 4 is carried into the inner chamber 5b of the suppressor 5 by the mobile phase, and is transferred to the cation exchange membrane tube 5.
It comes into contact with the scavenger liquid in the outer chamber 5c through the channel a, and the cations in the liquid to be measured are exchanged with H ⁺ ions. The liquid to be measured flowing out of the inner chamber 5b of the suppressor 5 is transported again by the mobile phase, and the acid conductivity is detected by the conductivity meter 6.

2 and 3 are chromatograms drawn by guiding the detection signals of the conductivity meters 4 and 6 detected as described above to a recorder (not shown). In the figures, the horizontal axis is the time T ( The unit is minutes), and the vertical axis represents conductivity (units are μs/cm). Further, A is a peak based on the detection signal of the conductivity meter 4 and indicates the conductivity of the liquid to be measured, and B is a peak based on the detection signal of the conductivity meter 6 and indicates the acidity of the liquid to be measured. Shows conductivity. In addition, Fig. 2 shows a sodium chloride (NaCl) solution of 0.28 milliequivalents as the liquid to be measured.
This is a chromatogram obtained by injecting 100μ of . As is clear from the chromatograms in FIGS. 2 and 3, according to the embodiment of the present invention, the conductivity and acid conductivity of the liquid to be measured can be accurately measured based on peaks A and B.

<Effects of the Invention> According to the present invention as described in detail above, the required amount of the liquid to be measured is extremely small, there is no need to replace the H ⁺ type cation column, etc., and the conductivity of the liquid to be measured is reduced. A method and apparatus capable of simultaneously measuring acid conductivity and acid conductivity are realized. That is, an amount sufficient to fill 3 g of the measuring tube of the sampling valve 3 (usually 100 ~
Only 1000μ) of the liquid to be measured is required.
The required amount of the liquid to be measured is extremely small compared to the conventional example. In addition, since the scavenge liquid is constantly flowing in the outer chamber 5c of the suppressor 5 and the cation exchange membrane tube 5a is kept in the H ⁺ type, it is not possible to regenerate it like the H ⁺ type cation exchange resin tube in the conventional example. No operation or replacement is required. Furthermore, since the conductivity meters 4 and 6 are used to measure the conductivity and acid conductivity of the same liquid to be measured, the conductivity and acid conductivity of the liquid to be measured can be measured simultaneously. Incidentally, the conductivity meters 4 and 6 are as follows:
It is also possible to use it with a normal conductivity meter used to measure anions and cations in a liquid to be measured.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIGS. 2 and 3 are chromatograms created using the embodiment of the present invention. 1a to 1e...tank, 2a, 2b...pump, 3
... Sample collection valve, 4, 6 ... Conductivity meter, 5 ... Suppressor, 7 ... Constant temperature bath.

Claims (1)

[Scope of Claims] 1. A certain amount of the liquid to be measured is sampled, the conductivity of the liquid to be measured is detected, and then the cations in the liquid to be measured are converted to H ⁺ by ion exchange using a cation exchange membrane. A method for measuring electrical conductivity and acid conductivity, characterized in that the conductivity and acid conductivity of the liquid to be measured are simultaneously measured by exchanging with ions and then detecting the acid conductivity of the liquid to be measured. 2. A sample collection valve that collects a certain amount of the liquid to be measured, a first conductivity meter that measures the conductivity of the liquid to be measured, and a cation exchange membrane tube that divides the interior into an inner chamber and an outer chamber. a suppressor for flowing a scavenge liquid containing H ⁺ ions into an outer chamber and guiding the effluent from the first conductivity meter to the inner chamber; and a second suppressor for detecting the conductivity of the fluid eluted from the inner chamber of the suppressor. a conductivity meter, and the conductivity and acid conductivity of the liquid to be measured are simultaneously measured by measuring the acid conductivity of the liquid to be measured with the second conductivity meter. Measuring device for rate and acid conductivity.