JPH02247559A - Carbon content measuring instrument - Google Patents

Abstract

PURPOSE:To make measurement with high accuracy by providing a flow rate control section, fluctuating the supply rate of an extraction gas and concentrating low-concn. carbon dioxide (CO2). CONSTITUTION:A soln. mixture composed of a sample from which inorg. carbon is removed in a deaerator 6 and a reaction liquid is sent by a pressurizing pump 10 to a reactor 11 where an oxidizing agent and the org. carbon in the sample are brought into reaction to form CO2. The CO2 is extracted in an extractor 13. Namely, the fluid is cooled in an extraction column 24 of the extractor 13 and is separated to the CO2 and drain water. The CO2 contg. an inert gas is sent from the upper part of the column 14 to a detector 16. A solenoid valve 22 of a flow rate regulating mechanism 21 and a mass flow controller 23 are alternately and repeatedly turned on and off by the control of a control device 24 at this time and the concn. of the CO2 in the extractor 13 is increased while the extraction gas is held interrupted. The CO2 increased in the concn. in the extractor 13 is sent to the detector 16 during the on time when the supply of the extraction gas is executed in succession to the above and, therefore, the CO2 is measured with the high accuracy without increasing the detecting sensitivity of the detector 16.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention is directed to T O which can measure the amount of organic carbon.
The present invention relates to a C (Total Organic Carbon) meter, and particularly to a carbon amount measuring device that can measure trace amounts of organic carbon contained in ultrapure water.

``Conventional technology'' Generally, when testing the quality of ultrapure water, a carbon amount measuring device is used to oxidize and decompose organic matter to convert it into carbon dioxide and measure the amount of carbon dioxide to determine the amount of organic carbon. It is being

This carbon amount measuring device reacts organic carbon contained in a sample liquid with an oxidizing agent at high temperature to generate carbon dioxide from the organic carbon. It has an extractor that extracts carbon dioxide and a detector that measures the amount of carbon dioxide extracted by the extractor, and the organic carbon in the sample is quantified based on the output data from this detector. I have to.

In addition, an extraction gas passage is connected to the lower part of the extractor, and the extraction gas supplied through this extraction gas passage stirs the exhaust liquid supplied from the reactor, and the exhaust liquid is converted into carbon dioxide. Only carbon can be extracted.

"Problem to be Solved by the Invention" By the way, in the carbon amount measuring device configured as described above, when carbon dioxide is to be detected with high precision, the detection sensitivity of the detector is increased to cope with the problem. However, if the concentration of carbon dioxide contained in the sample itself is low, it cannot be dealt with simply by increasing the detection sensitivity of the detector, resulting in a problem that accurate analysis of the sample cannot be performed.

This invention was made in view of the above circumstances, and aims to provide a carbon content measuring device that can detect, for example, low concentration carbon dioxide with high accuracy without adjusting the detector. do.

"Means for solving the problem" In order to achieve the above purpose, a reactor is used to react organic carbon contained in a sample liquid with an oxidizing agent at high temperature to generate carbon dioxide from the organic carbon. , an extractor for extracting carbon dioxide from the sample passed through the reactor, and a detector for measuring the amount of carbon dioxide extracted by the extractor, and based on the output from the detector, In a carbon amount measuring device for quantifying organic carbon in a sample, an extraction gas is supplied to the extractor for stirring the effluent discharged from the reactor and extracting carbon dioxide from the effluent. Further, a flow rate adjustment mechanism for adjusting the flow rate of the extraction gas is provided in the middle of this extraction gas flow path, and further, a flow rate adjustment mechanism for adjusting the flow rate of the extraction gas is provided to the flow rate adjustment mechanism. A flow rate control unit is provided to vary the amount.

"Operation" According to the present invention, since the flow rate control section is provided to control the flow rate adjustment mechanism and vary the supply amount of extraction gas, the supply of extraction gas is cut off or becomes small. During this time, the inside of the extractor becomes in a state where the concentration of carbon dioxide is increased, and then when the supply of extraction gas is started or the supply amount becomes large, the concentration of carbon dioxide inside the extractor is increased. Carbon will be sent to the detector.

"Example" Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2.

First, in FIG. 1, what is indicated by the symbol l is a sample supply pump, and on the suction side of this sample supply pump l, there is provided a sample supply pipe 2 through which a fixed amount of sample containing organic carbon is supplied. .

Further, a pipe 3 is provided on the discharge side of the sample supply pump 1, and a reaction liquid for reacting with the sample supplied from the sample supply pipe 1 is provided in the middle of the pipe 3. A liquid supply means 4 is provided. This reaction liquid supply means 4 has a reaction liquid supply pump 5,
This reaction liquid supply pump 5 supplies water contained in the sample.
An oxidizing agent such as Beroxonisulfide Calorum to generate carbon dioxide, which is an inorganic carbon, from organic carbon, and a sulfuric acid solution to drive out carbon dioxide, which is an inorganic carbon and a weak acid initially contained in the sample. A reaction solution consisting of an acidic solution such as the following is supplied as appropriate.

A deaerator 6 is provided downstream of the pipe 3.

This degassed Be has an air supply pipe 7 connected to the lower part that feeds an inert gas such as helium or nitrogen, and the inert gas supplied through the air supply pipe 7 is inside the deaerator 6. The mixture of the reaction solution (sulfuric acid solution) and the sample is stirred and mixed with each other in the form of bubbles, and carbon dioxide (inorganic carbon) in the sample is degassed.

The carbon dioxide separated inside the deaerator 6 and the inert gases such as helium and nitrogen supplied through the air supply pipe 7 are transferred to a plurality of exhaust pipes connected to the upper part of the deaerator 6. 8 so that it is discharged to the outside.

A pipe 9 is connected to the discharge port of the deaerator 6, and a pressure pump IO1 reactor 11 and a fixed throttle 12 are sequentially provided in the middle of the pipe 9.

The pressure pump 10 is for supplying a mixed liquid consisting of the sample and a reaction liquid into a reactor, which will be described later, at a constant pressure and flow rate, and the reactor 11 is equipped with a drum heater (not shown). The pipe 9 is spirally wound along the groove (as shown) formed around the pipe 9, and a thermocouple (as shown) is attached to the wall of the pipe 9 to detect the temperature inside the pipe. The temperature inside the pipe 11 is controlled to be constant at all times. In this reactor 11, the reaction liquid (oxidizing agent) and organic carbon in the sample are reacted to generate carbon dioxide from the organic carbon.

The fixed throttle 12 is for increasing the reaction pressure inside the reactor 11, and prevents the reaction liquid from vaporizing even if the temperature of the reactor 11 exceeds the boiling point of water. It is something.

Further, at the end of the pipe 9 and downstream of the fixed throttle 12, an extractor 13 is provided for extracting carbon dioxide from the sample water that has undergone reaction in the reactor 11.

This extractor 13 includes an extraction tower 14 that is installed vertically and separates a liquid mixture supplied through piping 9 into carbon dioxide and drain water (residue), and an extraction tower 14 that is installed around the extraction tower 14. A cooling pipe 15 is provided to cool the extraction tower 14 with cooling water supplied and discharged through pipes 15A and 15B, and inside the extraction tower 14, the pipe is The fluid supplied through the reactor 9 (containing carbon dioxide produced from organic carbon after the reaction is completed in the reactor 11) is spouted out together with an inert gas such as helium or nitrogen.

Further, in the upper part of the extraction tower 14, after removing water vapor remaining in the extraction gas (carbon dioxide containing inert gas) discharged from the extraction tower 14 with a dehumidifier (as shown), the extraction A pipe 17 equipped with an infrared analyzer 16 (detector) for measuring the concentration of carbon dioxide in the gas is connected.

Based on the results of the analysis by the infrared analyzer 16, the proportion of organic carbon contained in the sample supplied from the sample supply pipe 2 is calculated as appropriate.

Further, a pipe 20 (extraction gas flow path) for supplying an inert gas as an extraction gas into the extraction tower 14 is provided at the lower part of the extraction tower 14 in the extractor 13.
A flow rate adjustment mechanism 21 that adjusts the flow rate of the extraction gas is provided in the middle of the flow rate.

This style ffi! The adjustment mechanism 21 includes a solenoid valve 22 that supplies and stops the extraction gas, and a mass flow controller 23 that adjusts the flow rate of the extraction gas to be constant. is code 2
This is performed by a control device (flow rate control section) shown at 4.

This control device 24 (the flow adjustment mechanism 21 consisting of the solenoid valve 22 and the mass flow controller 23 is turned ON1)
A control signal (2) for 0FF control is supplied to the electromagnetic valve 22 and the mass flow controller 23 through the signal line 25, respectively.

Further, this control device 24 also controls the sample supply pump 1 described above.
1 reaction liquid supply pump 5, pressurized bomb 7'lO5 reactor 11
Control signals (1) to (2) for controlling 0N10FF are supplied to the sample supply pump 1, reaction liquid supply pump 5, pressure pump 10, and reactor 11 through signal lines 26 to 29, respectively.

Further, a pipe 30 is provided at the bottom of the extraction tower 14 in the extractor 13, and this pipe 30 allows the drain after carbon dioxide has been extracted in the extraction tower 14 to be discharged to the drain tank 31. It has become.

Next, the sample supply pump 1, the reaction liquid supply pump 5, and the pressure pump 1 in the carbon content measuring device configured as described above will be described.
0. The operations of the reactor 11, solenoid valve 22, and mass flow controller 23 will be explained with reference to the time chart of FIG.

According to this time chart, first, measurement starts (time O
), the sample supply pump 1 and the reaction liquid supply pump 5 are turned on, and after a certain period of time (time 1.), the pressure pump 10, the reactor 11. The solenoid valve 22 and mass flow controller 23 are turned on.

Nao, the above are the magnetic valve 22 and the mass flow controller 23.
is not always ON, but ON10F
Repeat F at regular intervals. For example, when the OFF time is 5 minutes and the ON time is 10 minutes, these solenoid valves 22 and mass flow controller 23 are turned ON and OFF.
Control is repeated alternately.

As a result, during the OFF period (5 minutes) when the extraction gas supply is cut off, the inside of the extractor 13 becomes in a state where the carbon dioxide concentration is increased, and then during the ON period when the extraction gas supply is performed. (during 10 minutes), the concentrated carbon dioxide in the extraction '1A 13 is sent to the infrared analyzer 16 to concentrate the sample containing low concentration of carbon dioxide. , it is possible to obtain the effect that the sample can be measured with less error.

In addition, in the above-mentioned carbon amount measuring device, the ON10 of the solenoid valve 22 and the mass flow controller 23 is turned on by the control signal
Although the FF time is set, the content of control by this control signal ■ can be set to, for example, 2 minutes of concentration time when OFF and 5 minutes of analysis time when ON. The rate may be changed as appropriate. Furthermore, the solenoid valve 22 and the mass flow controller 23 do not completely stop the flow of the inert gas (the flow rate,
This concentration rate may be adjusted by controlling.

In addition, the output data of the infrared analyzer 16 obtained by controlling the solenoid valve 22 and the mass flow controller 23 in a 0N10FF manner as described above is substituted into an arithmetic expression that has been experimentally set in advance under the same conditions. By this,
Calculate the amount of organic carbon contained in the sample.

"Effects of the Invention" As explained in detail above, according to the present invention, since the flow rate control section that controls the flow rate adjustment mechanism to vary the supply amount of extraction gas is provided, the supply of extraction gas is If the carbon dioxide concentration inside the extractor becomes high while the gas is cut off or becomes small, and then the extraction gas supply starts or the supply amount becomes large,
The carbon dioxide enriched in the extractor will be sent to a detector.

In other words, it is possible to concentrate carbon dioxide at low concentrations,
The effect is that the carbon dioxide can be measured with high accuracy without particularly adjusting the detector as in the conventional case.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is an overall schematic system diagram, and FIG. 2 is a time chart showing control details of a pump, etc., which is a driving device. It is. 11...Reactor, 13...Extractor, 1
6... Infrared analyzer (detector), 20...
... Piping (extracted gas flow path), 21 ... Flow rate adjustment mechanism (22 ... Solenoid valve, 23 ... Mass flow controller), 24 ... Control Device (flow control part).

Claims (1)

[Scope of Claims] A reactor that reacts organic carbon contained in a sample liquid with an oxidizing agent at high temperature to generate carbon dioxide from the organic carbon, and a reactor that generates carbon dioxide from the sample that has passed through the reactor. carbon dioxide, and a detector that measures the amount of carbon dioxide extracted by the extractor, and the amount of organic carbon in the sample is determined based on the output from the detector. In the amount measuring device, the extractor is provided with an extraction gas flow path through which an extraction gas for stirring the exhaust liquid discharged from the reactor and extracting carbon dioxide from the exhaust liquid is supplied, and A flow rate adjustment mechanism that adjusts the flow rate of the extraction gas is provided in the middle of the extraction gas flow path, and the flow rate adjustment mechanism further includes a flow rate control section that changes the amount of extraction gas supplied by the flow rate adjustment mechanism. A carbon amount measuring device characterized by being provided with.