JP2763275B2 - Automatic chlorine ion analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic chlorine ion analyzer for highly precise and automatic analysis of ultra-trace chlorine ions contained in water such as water supply, condensate water and reactor water in a light water reactor type nuclear power plant. About.

[0002]

2. Description of the Related Art In general, water quality analysis of water supply, condensate and reactor water in a light water reactor type nuclear power plant is an important measurement item in monitoring a corrosive environment such as piping in the power plant. Is extremely important in preventing stress corrosion cracking of stainless steel pipes and the like. Therefore,
For example, in a boiling water type (BWR) nuclear power plant, it is specified that the chlorine ion concentration in the condensed water be kept at about 100 ppb or less.

In the case of measuring chloride ions contained in such condensate and the like, conventionally, silver nitrate is added to sample water, and the chloride ion concentration is measured by turbidimetry using a spectrophotometer.

[0004]

However, according to the above-mentioned analysis method, there is a problem that it is difficult to accurately measure a chloride ion concentration of 100 ppb or less. In the past, since the analysis was performed manually in accordance with the low sensitivity of the analysis, the analysis operation was cumbersome, and the analysis workers could be exposed to radiation by radioactive substances contained in the sample water. Was.

[0005] Recently, an ion selective electrode has been developed as an alternative to the turbidimetric method using an ion selective electrode. Trace chlorine ion (0 to 20 pp
No one could automatically analyze b) with high precision and continuously.

An object of the present invention has been made in view of such circumstances, and an object of the present invention is to provide a chlorine ion automatic analyzer capable of automatically and automatically analyzing ultra-trace chlorine ions in sample water with high accuracy. is there.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a chlorine ion standard solution tank storing a constant concentration of a chlorine ion standard solution, and a fixed amount connected to an outlet of the chloride ion standard solution tank. A constant flow pump for supplying a chlorine ion standard solution, and a chlorine ion standard solution supplied from the constant flow pump and makeup water supplied from a makeup water supply source via an ion exchange resin tower to form a mixture having a predetermined concentration. A mixer for obtaining a chlorine ion standard solution, a head tank connected to an outlet of the mixer via a first valve, and a head tank provided between the head tank and the first valve A line filter connected to the inflow pipe via a second valve for filtering the sample water supplied from the sample water supply source; and a line filter connected to the outlet of the head tank via a flow controller to supply the sample water from the head tank. A pH adjuster for adjusting the pH of the chloride ion standard solution and the sample water to be performed; an electrode cell connected to the outlet of the pH adjuster for electrically measuring the chloride ions in the chloride ion standard solution and the sample water; A low-temperature cooler for keeping the inside of the electrode cell at a constant temperature; and a sequencer for controlling the start / stop of the constant flow pump and the opening / closing of the first and second valves. is there.

[0008]

In other words, according to the present invention, when the zero adjustment or the span of the analyzer is calibrated, the chlorine ion standard solution in the chlorine ion standard solution tank is supplied to the mixer by the constant flow rate pump, and the chlorine ion standard solution is converted into the mixer. Dilute and mix with make-up water (pure water) supplied from the ion exchange resin tower to obtain a low concentration chloride standard solution. Then, the low-concentration chlorine ion standard solution obtained by the mixer is passed through a head tank to pH
After the pH of the chloride standard solution is adjusted with this pH adjuster, the chloride standard solution is supplied to the electrode cell, and the indicated value of the analyzer is set to zero or the chloride ion concentration of the chloride standard solution. adjust. On the other hand, when measuring the chloride ion concentration in the sample water, the sample water is supplied to the head tank through a line filter, and the pH of the sample water is adjusted with a pH adjuster in the same manner as in the case of the calibration described above, and then the electrode cell is supplied to the electrode cell. Then, the chlorine ion concentration in the sample water is measured electrically.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an automatic analyzer for chlorine ions according to the present invention. A pipe is provided at an outlet of a chlorine ion standard solution tank 1 storing a chloride ion standard solution having a constant concentration (for example, about 2 ppm). The constant flow pump 2 is connected via the pump. The constant flow pump 2 supplies a fixed amount of a chlorine ion standard solution to the mixer 6.
The solenoid valve 4 is connected to the outlet of the valve 3 via a pipe 3. The outlet of the solenoid valve 4 is connected to an inlet pipe 5 connected to the inlet of a mixer 6. The chlorine ion standard solution in the chlorine ion standard solution tank 1 is supplied to the solenoid valve 4 and the inlet by a constant flow pump 2. It is supplied to a mixer 6 through a pipe 5.

An ion exchange resin tower 8 is connected to the inlet of the mixer 6 via a pipe 7 so that makeup water (pure water) is supplied from the ion exchange resin tower 8. I have. The ion-exchange resin tower 8 is for removing a trace amount of chlorine ions contained in the makeup water supplied from the solenoid valve 10 through the flow controller 9.
Is connected to a makeup water supply source (not shown) such as a reinforcing water tank.

On the other hand, a pipe 11 is connected to the outlet of the mixer 6.
The solenoid valve 12 is connected via the. This solenoid valve 12
A head tank inflow pipe 13 is connected to the outlet of
The water is mixed with make-up water in the mixer-6 to a predetermined concentration (for example, 20p).
pb) is supplied to the solenoid valve 12
And the head tank 1 through the head tank inflow pipe 13.
4.

One end of a sample water supply pipe 15 is connected in the middle of the head tank inflow pipe 13. The other end of the sample water supply pipe 15 is connected to an outlet of a line filter 17 via an electromagnetic valve 16, and a sample water supply source (not shown) such as a sample water tank is connected to the inlet of the line filter 17. The line filter 17 removes impurities contained in the sample water, and the sample water passing through the line filter 17 is supplied to the electromagnetic valve 16 and the sample water supply pipe 15.
And the head tank 1 through the head tank inflow pipe 13.
4.

A pH controller 20 is connected to the outlet of the head tank 14 via a pipe 18 and a flow controller 19. This pH controller 20 is a head tank 1
PH of chlorine ion standard solution and sample water supplied from 4
The electrode cell 21 is connected to the outlet of the pH controller 20. The electrode cell 21 is of a known type in which the chloride ion concentration is electrically measured by a chloride ion measurement electrode 22, and is provided with a constant temperature cooler 23 for keeping the inside of the electrode cell 21 at a constant temperature (about 5 ° C.).

A waste liquid treatment system 24 is connected to the outlet of the electrode cell 21 via a pipe. A drain pipe 26 is connected to the bottom of the chlorine ion standard liquid tank 1 via a solenoid valve 25, and an overflow pipe 27 is connected to the top of the head tank 14. And
The constant flow pump 2 and the respective solenoid valves 4, 10, 12, 1
6 and 25 are automatically started and stopped and opened and closed by a signal from the sequencer 28.

FIGS. 2 and 3 show the operation of the chlorine ion automatic analyzer constructed as described above. When analyzing chlorine ions contained in the sample water by the present apparatus, first, the analyzer is operated. Or perform span calibration. And
The solenoid valves 4 and 12 are opened as shown in FIG.
6 and 25 are closed, and the constant flow pump 2 supplies a fixed amount of the chloride ion standard solution in the chloride ion standard solution tank 1 to the mixer 6 via the inlet pipe 5. Then, the chlorine ion standard solution supplied to the mixer 6 is changed from, for example, 2 ppm to 20 pp by makeup water supplied from the ion exchange resin tower 8.
The diluted standard solution is diluted to about b and supplied to the head tank 14 via the solenoid valve 12 and the head tank inflow pipe 13.

The diluted standard solution supplied to the head tank 14 is supplied to a pipe 1 connected to the outlet of the head tank 14.
8, is supplied to a pH adjuster 20 via a flow adjuster 19. For example, formic acid is contained in the pH adjuster 20, and the chlorine ion standard solution supplied to the pH adjuster 20 is adjusted to pH 3.0 to 3.5 by the diffusion of formic acid. Then, the chloride ion standard solution whose pH has been adjusted by the pH adjuster 20 is supplied to the electrode cell 21 maintained at a constant temperature by the low-temperature cooler 23, and the chlorine ion concentration of the chloride ion standard solution is changed to the chlorine ion measurement electrode 22. Is measured electrically. The chloride ion concentration of the chloride standard solution measured by the chloride ion measurement electrode 22 is output from the chloride ion measurement electrode 22 as an electric signal, and
A correction operation is performed by inputting the result to the kenser 28, and zero or span calibration of the analyzer is automatically performed based on the operation result.

When the above-mentioned calibration mode is completed,
As shown in FIG. 3, the solenoid valves 4 and 12 are closed, the solenoid valve 16 is opened, and the mode switches to the chloride ion measurement mode. As a result, the sample water that has passed through the line filter 17 flows into the head tank 14 through the solenoid valve 16, the sample water supply pipe 15, and the head tank inflow pipe 13, and the electrode water flows from the head tank 14 through the pH adjuster 20. Sample water is supplied to the cell 21, and chloride ions in the sample water are electrically measured by the chloride ion measurement electrode 22.

As described above, in the present embodiment, since the chloride ions in the sample water are electrically measured by the chloride ion measuring electrode 22, ultra-trace chlorine ions of 20 ppb or less can be measured with high accuracy and continuously. . In addition, the start and stop of the constant flow pump 2 and each of the solenoid valves 4, 10, 12, 1
Since the opening and closing of the valves 6 and 25 are automatically performed by the signal from the sequencer 28, there is no need to manually analyze the chloride ions in the sample water as in the prior art, so that the burden on the analysis operator can be reduced and the radiation exposure can be reduced. Can be prevented.

In the above embodiment, a high-concentration chlorine ion standard solution is stored in the chlorine ion standard solution tank 1, and the standard solution is diluted with pure water when used. Chlorine standard solution tank 1
If stored in a small amount of chlorine in the air, the concentration of the standard solution changes due to contamination. I am getting liquid. The pH of the sample water is adjusted to 3.0 to 3.5 by the pH adjuster 20 in order to keep the output of the electrode 22 proportional to the chloride ion concentration.

[0020]

As described above, according to the present invention, the chloride ion concentration in water supply, condensate, reactor water, etc. of a light water reactor type nuclear power plant can be automatically analyzed with high precision, thereby improving the analysis sensitivity and improving the analysis workers. This can reduce the burden of exposure and the exposure.

[Brief description of the drawings]

FIG. 1 is a block diagram of an automatic chlorine ion analyzer according to one embodiment of the present invention.

FIG. 2 is an explanatory view of the operation of the automatic chloride ion analyzer according to the embodiment.

FIG. 3 is an operation explanatory view of the automatic chloride ion analyzer according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Chlorine ion standard liquid tank 2 ... Constant flow pump 4 ... Solenoid valve 6 ... Mixer 8 ... Ion exchange resin tower 9 ... Flow controller 10 ... Solenoid valve 12 ... Solenoid valve 14 ... Head tank 16 ... Solenoid valve 17 ... Line Filter 19: Flow controller 20: pH controller 21: Electrode cell 23: Low-temperature cooler 28: Sequencer

──────────────────────────────────────────────────続 き Continued on the front page (73) Patent holder 000211307 Chugoku Electric Power Co., Inc. 4-33, Komachi, Naka-ku, Hiroshima-shi, Hiroshima Prefecture (73) Patent holder 000230940 Japan Atomic Power Company 1-6 Otemachi, Chiyoda-ku, Tokyo No. 1 (73) Patent holder 000003078 Toshiba 72-72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa (73) Patent holder 000000239 Ebara Corporation 11-1 Asahi-cho, Haneda, Ota-ku, Tokyo (72) Inventor Shinji Sugibayashi 1 Toshiba R & D Center, Komukai, Kawasaki-shi, Kanagawa Prefecture, Japan (72) Inventor Yoshitake Morikawa 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture, Japan Toshiba Yokohama Office (72) Inventor Kazuo Fukase 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Inside the Toshiba Yokohama Office (72) Inventor Hiromasa Kashima Haneda, Ota-ku, Tokyo Town number 11 No. 1 stock company in Ebara (58) investigated the field (Int.Cl. ^6, DB name) G01N 27/416 G01N 27/26 381 G01N 31/00 G01N 33/18

Claims (1)

(57) [Claims] 1. A chlorine ion standard solution tank (1) storing a constant concentration of a chloride ion standard solution, and a constant amount of a chloride ion standard solution connected to an outlet of the chloride ion standard solution tank (1). A flow rate pump (2) is mixed with a chlorine ion standard solution supplied from the constant flow rate pump (2) and make-up water supplied from a make-up water supply source through an ion exchange resin tower (8) to obtain a predetermined concentration. A mixer (6) for obtaining a chloride ion standard solution, and a head tank (1) connected to an outlet of the mixer (6) via a first solenoid valve (12).
4), the head tank (14) and the first valve (1).
A line filter (17) connected through a second valve (16) to a head tank inflow pipe (13) provided between the apparatus and (2) to filter sample water supplied from a sample water supply source;
A flow controller (19) is provided at the outlet of the head tank (14).
For adjusting the pH of the chlorine ion standard solution and the sample water supplied from the head tank (14) and connected through
H adjuster (20); an electrode cell (21) connected to the outlet of the pH adjuster (20) for electrically measuring chloride ions in the chlorine ion standard solution and the sample water; and an electrode cell (21) Constant temperature cooler (23) that keeps the inside at a constant temperature
Starting and stopping the constant flow pump (2) and the first
For controlling the opening and closing of the second valve (16) and the second valve (12)
An automatic analyzer for chlorine ions, comprising a kensa (28).