JP2000171358A - Gas analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make introducible a calibration gas after quickly exhausting a measuring object gas from the inside of piping by switching between that sample gas is made to flow to a sampling probe side introducing passage or that the atmosphere is made to flow to the analyzer side by a valve mechanism. SOLUTION: At the time when an analyzer 15 is calibrated, a sample gas introducing circuit P3 is closed by operating a three-way directional control valve 17, and a branch pipe 18 opening to the atmosphere is communicated with an introducing passage P5 so that the atmosphere is introduced to the introducing passage P5 through an atmosphere suction filter 18. The concentration output of sample gas of the analyzer 15 rapidly approaches 0 by the introduction of the atmosphere, and measuring object gas remaining in piping up to the analyzer 15 from a three-way directional control valve 16 can be exhausted in a short time. Afterwared, the three-way directional control valve 16 is selected to be communicated with the calibration gas introducing passage P5, and the atmosphere is cut off by operating the three-way directional control valve 17. Calibration gases 5, 7 are properly introduced, a zero point is adjusted, and a span is adjusted. Thus, introducing time of the calibration gases 5, 7 can be shortened, and its consumption can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas analyzer for sampling a gas such as a combustion exhaust gas and measuring its components with an analyzer.

[0002]

2. Description of the Related Art A gas analyzer of this type is shown in FIG. FIG. 4 shows a flow of the conventional gas analysis system, but the sample gas collected by a sampling probe (not shown) is 120 to 1
Sample gas inlet P1 through conduit heated to 50 ° C.
It is led to. At the same time, it is led to the drain separator 1, where it is cooled to room temperature, separated into gas and drain,
Further, it is cooled to 5 ° C. by the primary cooler 2. The drain generated in the drain separator 1 and the primary cooler 2 is supplied to a pipe P2.
, And overflows from the drain outlet 4 to be drained. The substantially clean sample gas is sucked by the pump 10 from the primary cooler 2 via the gas introduction path P3, via the three-way switching valve 16 and the needle valve 9 for flow control. Fine dust is removed from the sample gas discharged from the pump 10 by the humidifier 11, the secondary cooler 12, and the filter 13. The completely cleaned sample gas is guided to the flow meter 14 via the introduction path P5, and is introduced to the analyzer 15.

[0003] In such a gas analyzer, calibration is performed to confirm that the function is normal. This calibration method includes a zero point adjustment standard gas (hereinafter referred to as a zero gas). There are two types: point adjustment and span adjustment using a span adjustment standard gas (hereinafter referred to as span gas). In the present invention, the zero gas and / or the span gas are referred to as calibration gas. First, when performing the zero point adjustment, the three-way switching valve 16 is operated to close the introduction path P3 of the sample gas, and the introduction path P4 for introducing the zero gas from the zero gas cylinder 5 is connected to the introduction path P5. At this time, the zero gas opening / closing valve 6 is opened. Then, zero gas is sucked by the pump 10 and introduced into the analyzer 15 to adjust the zero point of the analyzer. Similarly, when performing the span adjustment, the span gas cylinder 7 is closed with the sample gas introduction path P3 of the three-way switching valve 16 closed after the zero point adjustment.
Then, the span gas opening / closing valve 8 is opened, the introduction path P4 is connected to the introduction path P5, the span gas is sucked by the pump 10, and introduced into the analyzer 15 to adjust the span of the analyzer.

[0004]

The calibration in such a conventional analysis system is performed after the gas to be measured in the sample gas is completely exhausted from the flow path system. It takes a considerable amount of time to completely purge from the furnace, and it takes a long time before the gas in the piping of the calibration line is completely replaced with the calibration gas. As a result, expensive calibration gas has to be consumed during this time.
Further, it takes a considerable time to complete the calibration and completely purge the calibration gas. Therefore, there is a problem that the analysis work takes a long time. An object of the present invention is to provide a gas analyzer that solves such a problem.

[0005]

The gas analyzer according to the present invention comprises:
In order to achieve the above object, a calibration gas introduction path for introducing a calibration gas for calibrating the analyzer to the analyzer is connected to an introduction path for introducing gas collected from a sampling probe to the analyzer. In the gas analyzer provided with a switching valve mechanism for switching and introducing any of the sample gas and the calibration gas to the analyzer at the connection portion, the sample is introduced into the sampling probe side introduction path of the switching valve mechanism. An air introduction valve mechanism is provided for switching between flowing gas or opening to the atmosphere and conducting the air to the analyzer side. That is, at the time of calibration, the atmosphere is introduced before introducing the calibration gas into the analyzer, the gas to be measured is quickly and reliably discharged from the pipe, and then the calibration gas is introduced.

[0006]

FIG. 1 shows the configuration of a gas analyzer according to the present invention. In FIG. 1, the components and parts indicated by the same reference numerals as those in FIG. 3 are the same as those in FIG. In the present invention, the three-way switching valve 17 is provided on the introduction path P3 closer to the sampling probe side than the three-way switching valve 16. The branch pipe from the three-way switching valve 17 is open to the atmosphere.

Next, a calibration method in the gas analyzer of the present invention will be described. To calibrate the analyzer, the newly installed three-way switching valve 17 is operated to close the sample gas introduction circuit P3 and to connect the branch pipe 18 opening to the atmosphere to the introduction path P.
Connect to 5. Then, the atmosphere is immediately introduced into the introduction path P5 via the atmosphere suction filter 18. As shown in the calibration sequence diagram of FIG. 2, the concentration output of the sample gas indicated in the output of the gas analyzer approaches zero in a short time due to the introduction of the atmosphere. That is, the gas to be measured remaining in the pipe from the three-way switching valve 16 to the analyzer 15 can be discharged in a short time. After that, the three-way switching valve 16 is switched,
The calibration gas introduction path P4 is communicated with the introduction path P5, and the three-way switching valve 17 is switched to shut off the atmosphere.
Then, the calibration gases 5 and 7 are appropriately introduced into the analyzer 15, and the calibration of the zero point adjustment and the span adjustment is performed. That is, after confirming that the concentration output value of the analyzer has become almost zero, the introduction path of the three-way switching valve 16 is changed to the three-way switching valve 1 as shown in FIG.
The line is switched from the 7 side to the calibration gas, that is, the line connected to the zero gas cylinder 5 and the span gas cylinder 7. In this state,
Open the zero gas opening and closing valve 6, sends the time zero gas indicated by N ₂ in FIG. 2 the needle valve 9 side. After confirming that the concentration output value of the analyzer 15 has become zero, the zero point is adjusted.
After the zero point adjustment is completed, the zero gas on / off valve 6 is closed, the span gas on / off valve 8 is opened, the span gas is sent to the needle valve 9 side, and it is confirmed that the concentration output value of the analyzer 15 is saturated, and the span is adjusted. . When these calibrations are completed, 3
The one-way switching valve 16 is returned to the original position, and the sample gas is introduced into the introduction path P5.
To be introduced.

Although the present invention has been described above, it is not limited to the above and illustrated examples but includes various modifications. First, the introduction paths P3 and P, which are features of the present invention,
7, the atmosphere introduction valve mechanism 17 and the valve mechanism 16 for switching between the sample gas and the calibration gas. In the illustrated example, this is performed by a three-way switching valve. However, it is not always necessary to use a three-way switching valve. For example, as shown in FIG. 4, it is also possible to interpose electromagnetic on-off valves V1 to V4 in each introduction path and to operate these valves appropriately. In this case, the electromagnetic on-off valves V1 and V2, and V3 and V4 respectively perform the same function as the three-way switching valve. The present invention includes these modifications. Further, FIG. 2 shows a sequence diagram of the calibration according to the present invention, and the function of each valve has been described in the individual operation manually. However, the microcomputer system is introduced and the concentration output value of the analyzer is captured. By operating each valve, the calibration sequence can be fully automated. This full automation is also possible for FIG.

[0009]

Since the present invention is configured as described above, the time for introducing the calibration gas can be shortened.
The consumption of the calibration gas can be significantly reduced, and the running cost can be reduced. In particular, at the time of zero point adjustment, the consumption of expensive zero gas can be reduced to approximately one tenth by flowing atmospheric air until the value approaches zero.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a gas analyzer of the present invention.

FIG. 2 is a diagram showing a calibration sequence of the gas analyzer according to the present invention.

FIG. 3 is a diagram showing a modification of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional gas analyzer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drain separator 2 ... Primary cooler 3 ... Drain pot 4 ... Drain outlet 5 ... Zero gas cylinder 6 ... Zero gas on-off valve 7 ... Span gas cylinder 8 ... Span gas on-off valve 9 ... Needle valve 10 ... Pump 11 ... Humidifier 12 ... Secondary Cooler 13 ... Filter 14 ... Flow meter 15 ... Analyzer 16, 17 ... 3-way switching valve 18 ... Atmospheric suction filter V1-V4 ... Electromagnetic on-off valve P1 ... Gas inlet P2 ... Pipe line P3-P5 ... Introduction path

Claims (1)

[Claims] A calibration gas introduction path for introducing a calibration gas for calibrating the analyzer to the analyzer is connected to an introduction path for introducing a sample gas collected from a sampling probe into the analyzer. In a gas analyzer provided with a switching valve mechanism for switching and introducing any one of the sample gas and the calibration gas to the analyzer at the connection portion,
In the sampling probe side introduction path of the switching valve mechanism,
A gas analyzer provided with an air introduction valve mechanism for switching between flowing the sample gas or opening the air to the atmosphere and conducting the air to the analyzer side.