JPS594285Y2 - Total organic carbon measuring device - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a total organic carbon analyzer.

More specifically, this device consists of an injection section for a water sample, a combustor that heats and burns the injected water sample, a condenser that condenses water vapor by passing the resulting combustion gas, and a carbon dioxide gas that exits the condenser. A total organic carbon measuring device comprising a concentration measuring section, a receiver for temporarily storing condensed water generated in the condenser;
The present invention relates to a total organic carbon measuring device which is equipped with a supply pipe line for supplying a portion of the condensed water from the receiver to an injection section for use as zero calibration water.

In recent years, with the advanced treatment of wastewater and the strengthening of water quality regulations, total organic carbon measuring devices (devices that measure total organic carbon in water,
There is an increasing need for highly sensitive measurements using TOC meters (also referred to as TOC meters).

There are various difficulties in high-sensitivity measurements, one of which is the problem of zero calibration water.

Zero calibration water is important water used to calibrate the zero point of a TOC meter and to prepare a standard solution for creating a calibration curve.

Originally, carbon content should not be included in zero calibration water, but
Generally available pure water (such as distilled water) contains a non-negligible amount of carbon.

For example, in commercially available distilled water, total organic carbon of about 1 to 0.5 ppm is often detected.

Currently, in order to obtain high-purity water suitable for use as zero calibration water, in addition to distillation, it is necessary to perform complex processing that combines several processing methods, such as activated carbon treatment and reverse osmosis.

This idea was devised in view of these circumstances, and one of its main features is that it is different from the conventional total organic carbon measuring device (T
The purpose of this method is to use water generated during measurement in an OC meter as zero calibration water.

As a result, ideal zero calibration water of high purity can be obtained easily and with an extremely simple structure.

That is, the conventional total organic carbon measuring device consists of an injection part for a water sample, a combustor that heats and burns the injected water sample (for example, at 400°C or higher), and a combustor that condenses water vapor by passing the obtained combustion gas. It basically includes a condenser and a part that measures the concentration of carbon dioxide gas that exits the condenser.

Therefore, condensed water is generated in the condenser. However, conventionally, this condensed water was simply discharged as is.

While conducting research to improve this type of device, the inventor discovered that
The inventors discovered that the condensed water is most suitable as zero calibration water and completed the present invention.

This invention will be explained in detail below based on the embodiments shown in the figures.

Note that this invention is not limited by this.

First, in Figure 1, total organic carbon measuring device (hereinafter TOC)
1 includes a sample container 2, an inorganic carbon removal section 3, a three-way switching cock 4, a quantitative raw water sample injection (sending) section 5, a combustion tube 6, a condenser 7, a filter 8, an infrared gas separation section 9 are connected in this order using appropriate pipes, and the quantitative raw water sample injection section 5 is connected to a carrier gas supply section 10 and a water pump 1.
It is connected with 1.

12 is a condensed water receiver, and 13 is a condensed water receiver.
This is a zero calibration water supply pipe extending to one port of the direction switching pot 4.

Note that 14 is an excess condensed water outlet of the receiver 12.

The combustion tube 6 is wound with an electric heating band 15 having a length of 300 mm that can raise the temperature to 900° C. by heat exchange on the outside, and is set so that the internal temperature can be maintained at 400° C. or higher.

On the other hand, tricobalt tetraoxide 16 is introduced into the combustion tube 6 as an oxidation catalyst.

Said condenser 7 is connected to the outlet of the combustion tube 6 and cools the gas obtained in the combustion tube 6 to about 1.5° C., thereby condensing the water vapor into water.

Next, the operation of the TOC meter 1 having the above configuration will be explained.

First, a water sample is put into the sample container 2, and purified air is supplied from the carrier gas supply section 10 through a check valve (not shown).
Injection part 5 as carrier gas and auxiliary gas at 00m1/min.
supply and maintain steady state.

In other words, purified air is discharged into the atmosphere from the injection section 5 in a steady state through the combustion tube 6, the thermomodular (electronic) condenser 7, the filter 8, and the infrared gas analysis section 9 (of course, the air flows in reverse). Appropriate preventive measures are provided).

Further, the combustion tube 6 and the condenser 7 are controlled at a temperature of 400° C. or higher and approximately 1.5° C., respectively.

After the above preparations, the water pump 11 is operated, and a water sample is continuously or intermittently transferred to the combustion tube 6 through the inorganic carbon removal section 3, the three-way switching pot 4, and the injection section 5, and then Heat to 400℃ or higher.

In this way, the pure water component is converted into water vapor, and the organic carbon component is combusted and converted into carbon dioxide gas, which reaches the condenser 7, where the water vapor is cooled and condensed, and stored in the receiver 12 as condensed water.

On the other hand, the concentration of carbon dioxide gas is measured by the infrared gas analyzer 9.
Based on that value, the total organic carbon content of the water sample can be obtained accordingly.

By the way, for the above-mentioned general measurement of total organic carbon content, it is necessary to calibrate the zero point before starting the measurement and at appropriate intervals.

In this case, by switching the three-way switch 4, the zero calibration water supply pipe 13 and the injection part 5 are brought into communication with each other, and a part of the condensed water temporarily stored in the receiver 12 is guided to the combustion pipe 6 in the same manner as during measurement. Perform the operation and perform zero calibration.

It is clear from the purpose of this device that the condensed water contains almost no carbon content, and therefore zero calibration with this condensed water allows extremely accurate measurements.

The receiver can be constructed as shown in FIG. 2, unlike the above embodiments.

That is, the receiver 12a includes a closed container 17a and an inlet pipe 18 from the condenser 7a having an opening at the bottom of the container.
a, a deaeration (or aeration) side pipe 20a that introduces the gas that has passed through the infrared gas analyzer 9a into the bottom of the container via a carbon dioxide absorber 19a filled with soda lime, and a side pipe 20a provided at the top of the container. Exhaust port 14 for excess condensed water and purge gas
A.

In this receiver 12a, a trace amount of carbon dioxide contained in the condensed water can be discharged by aeration through the degassing pipe 20H, and higher purity condensed water, that is, zero calibration water can be obtained. Therefore, it is possible to measure the total organic carbon concentration with higher accuracy.

In particular, in a TOC meter that uses a continuous water sample injection method, carbon dioxide gas is constantly generated, so it is likely to be included in the condensed water. Therefore, the above-mentioned deaeration pipe 20a has a large effect, and nitrogen gas is used as the aeration gas. It is also possible to use

Furthermore, in the apparatus of the above-mentioned embodiments, the three-way switching switch is automatically switched by a command signal transmitted from an external programmer, etc., and zero calibration water (condensed water) is introduced into the combustion pipe. .

If the output signal from the infrared gas analyzer at this time fluctuates from zero, the so-called drift is corrected to zero by an automatic zero calibration circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional explanatory diagram showing one embodiment of the total organic carbon measuring device according to this invention, and FIG. 2 is a partial functional explanatory diagram of another embodiment. 1... Total organic carbon measuring device, 5... Injection part, 6... Combustion tube, 7... Condenser,
9... Infrared gas analysis section, 12...
Receiver, 13...Zero calibration water supply pipe.

Claims (1)

[Scope of utility model registration request] It includes a water sample injection section, a combustor that heats and burns the injected water sample, a condenser that passes the obtained combustion gas and condenses water vapor, and a concentration measuring section of carbon dioxide gas that has exited the condenser. The total organic carbon measuring device includes a receiver that temporarily stores condensed water generated in a condenser, and a supply pipe that supplies some of the condensed water from this receiver to an injection section for use as zero calibration water. A total organic carbon measuring device equipped with a