JP4013374B2 - Gas analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas analyzer that samples a gas such as combustion exhaust gas and measures its components with an analyzer.
[0002]
[Prior art]
This type of gas analyzer is shown in FIG. Although FIG. 4 shows a conventional gas analysis system in flow, a sample gas collected by a sampling probe (not shown) is led to a sample gas inlet P1 through a conduit heated to 120 to 150 ° C. It is burned. At the same time, it is led to the drain separator 1 where it is cooled to room temperature, separated into gas and drain, and further cooled to 5 ° C. by the primary cooler 2. The drain generated in the drain separator 1 and the primary cooler 2 enters the drain pot 3 through the pipe P2, and overflows and drains from the drain outlet 4. The almost cleaned sample gas is sucked by the pump 10 from the primary cooler 2 through the three-way switching valve 16 and the needle valve 9 for flow rate control via the gas introduction path P3. 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 through the introduction path P5 and introduced into the analyzer 15.
[0003]
In such a gas analyzer, calibration is performed to confirm that its function is normal. This calibration method includes zero point adjustment with a standard gas for zero point adjustment (hereinafter referred to as zero gas). There are two types of span adjustment: 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 the zero point adjustment is performed, the three-way switching valve 16 is operated to close the sample gas introduction path P3, 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, the 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 and the span gas opening / closing valve 8 are opened with the sample gas introduction path P3 of the three-way switching valve 16 closed after the zero point adjustment, and the introduction path P4 is connected to the introduction path P4. Connected to P5, the span gas is sucked by the pump 10 and introduced into the analyzer 15 to adjust the span of the analyzer.
[0004]
[Problems to be solved by the invention]
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, and this is a considerable purge for the complete purge of the sample gas from the flow path system. It takes time, and a great deal of time is required until the gas in the piping of the calibration line is completely replaced with the calibration gas. As a result, expensive calibration gas had to be consumed during this period. It also takes a considerable amount of time to complete the calibration and completely purge the calibration gas. Therefore, there is a problem that analysis work takes a long time.
The object of the present invention is to provide a gas analyzer that solves such problems.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the gas analyzer of the present invention introduces a calibration gas for calibrating the analyzer into the introduction path for introducing the gas collected from the sampling probe into the analyzer. A gas analyzer provided with a switching valve mechanism for switching and introducing either the sample gas or the calibration gas to the analyzer at the connection portion. The sampling probe side introduction path is provided with an air introduction valve mechanism for switching whether the sample gas is circulated or opened with the atmosphere to conduct the atmosphere to the analyzer side. That is, at the time of calibration, the atmosphere is introduced before the calibration gas is introduced into the analyzer, and the gas to be measured is quickly and reliably discharged from the pipe, and then the calibration gas is introduced.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the configuration of the gas analyzer of the present invention. 1 are the same as those shown in FIG. 3, and their functions and operations are the same as those described above, so the details are omitted. In the present invention, the three-way switching valve 17 is interposed in the introduction path P3 closer to the sampling probe than the three-way switching valve 16. A branch pipe from the three-way switching valve 17 opens to the atmosphere.
[0007]
Next, a calibration method in the gas analyzer of the present invention will be described.
When calibrating the analyzer, the newly installed three-way switching valve 17 is operated to close the sample gas introduction circuit P3, and the branch pipe 18 opened to the atmosphere is communicated with the introduction path P5. Then, the air is immediately introduced into the introduction path P5 through the air suction filter 18. As shown in the calibration sequence diagram of FIG. 2, the concentration output of the sample gas shown in the output of the gas analyzer by the introduction of the atmosphere approaches zero in a short time. 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. Thereafter, the three-way switching valve 16 is switched to connect the calibration gas introduction path P4 to the introduction path P5, and the three-way switching valve 17 is switched to shut off from the atmosphere. Then, the calibration gases 5 and 7 are appropriately introduced into the analyzer 15 to perform zero point adjustment and span adjustment calibration. That is, after confirming that the concentration output value of the analyzer is almost zero, the introduction path of the three-way switching valve 16 is connected to the calibration gas, that is, the zero gas cylinder 5 and the span gas cylinder from the three-way switching valve 17 side as shown in FIG. Switch to line 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. The zero point adjustment is performed after confirming that the concentration output value of the analyzer 15 has become zero. After the zero point adjustment is completed, the zero gas opening / closing valve 6 is closed, the span gas opening / closing 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 adjustment is performed. . When these calibrations are completed, the three-way switching valve 16 is returned to the original position so that the sample gas is introduced into the introduction path P5.
[0008]
Although the present invention is as described above, the present invention is not limited to the above and illustrated examples, and includes various modifications. First, the introduction paths P3 and P7, the atmospheric introduction valve mechanism 17 and the switching mechanism 16 for switching between the sample gas and the calibration gas, which are features of the present invention, are configured by a three-way switching valve in the illustrated example. However, it is not always necessary to use a three-way switching valve. For example, as shown in FIG. 4, electromagnetic opening / closing valves V1 to V4 may be provided in the respective introduction paths so that these can be operated as appropriate. In this case, the electromagnetic on-off valves V1 and V2, and V3 and V4 perform the same function as the three-way switching valve, respectively. The present invention includes these modifications.
Further, FIG. 2 shows a calibration sequence diagram of the present invention, and the function of each valve is described manually in terms of individual operations. A microcomputer system is introduced and the concentration output value of the analyzer is captured. It is also possible to fully automate the calibration sequence by operating each valve. This full automation is also possible for FIG.
[0009]
【The invention's effect】
Since the present invention is configured as described above, the calibration gas introduction time can be shortened, the consumption of the calibration gas can be significantly reduced, and the running cost can be reduced. In particular, it has become possible to reduce the consumption of expensive zero gas to almost one tenth by flowing atmospheric air until it approaches zero during zero point adjustment.
[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 a 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 ... Air intake filter V1-V4 ... Electromagnetic on-off valve P1 ... Gas inlet P2 ... Pipe lines P3-P5 ... Introduction passage

Claims (2)

An introduction path for introducing the sample gas collected from the sampling probe into the analyzer ;
A zero gas on-off valve for introducing zero point calibration gas into the analyzer via the introduction path ;
Through the introduction passage and a air introduction valve mechanism for conducting air to the analyzer side,
After controlling the atmosphere introduction valve mechanism and exhausting the residual gas in the introduction path by conducting the atmosphere to the analyzer side,
A microcomputer that controls the atmosphere introduction valve mechanism to shut off the atmosphere, and controls the zero gas on-off valve to introduce the zero point calibration gas into the analyzer to perform zero point calibration of the analyzer. A gas analyzer further comprising a system . An introduction path for introducing the sample gas collected from the sampling probe into the analyzer;
A zero gas on-off valve for introducing zero point calibration gas into the analyzer via the introduction path;
Using a gas analyzer equipped with an atmosphere introduction valve mechanism for conducting the atmosphere to the analyzer side through the introduction path,
After exhausting the residual gas in the introduction path by operating the atmosphere introduction valve mechanism and conducting the atmosphere to the analyzer side,
While operating the atmosphere introduction valve mechanism to shut off the atmosphere,
A calibration method for a gas analyzer, wherein the zero point calibration of the analyzer is performed by operating the zero gas on-off valve and introducing the zero point calibration gas into the analyzer.

Images