JP3448177B2 - Direct gas analysis method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a direct method for analyzing gas using a laser, but contributes to the improvement of the safety of the analyzer.

[0002]

2. Description of the Related Art Conventionally, in measuring gas concentration in a power plant, etc., main gas components can be measured online by gas chromatography, etc., but they are contained in trace gas components and gas. For powder composition,
Since the gas and powder were sucked, they were analyzed, and it was difficult to measure them online.

[0003]

Even a trace amount of gas components and powder composition can be monitored online by installing a gas analyzer using a laser.
However, in the gas analyzer using the laser, since the analyzer is directly installed in the pipe, if a leak occurs from the pipe to the analyzer, the gas analyzer using the laser has an irreparable influence. there is a possibility.

[0004]

[Means for Solving the Problems] The above-mentioned problem is that a measurement pipe is branched from a pipe of a gas to be measured whose pressure is equal to or higher than the atmospheric pressure, and the measurement pipe is hermetically sealed and contains a gas analyzer using a laser. In a method for directly analyzing a gas, in which a container is connected, and further, a flange having a shutoff valve and a laser optical window is provided in the measuring pipe, the flange having the laser optical window is doubled, and two laser optical increase in the internal pressure in the space partitioned by a flange provided with a window, more reduction in pressure difference between the measurement pipe, to detect the leakage of gas from the measuring pipe, if the gas leak is detected The laser by the gas analyzer using the laser is quickly stopped, and the shutoff valve installed in the measuring pipe is closed.

Further, a line opened to the atmosphere is connected to a space partitioned by a flange provided with two laser optical windows through a shutoff valve, and when a gas leak is detected, the shutoff valve of the atmospheric release line is opened. It is also characterized by

[0006]

FIG. 2 shows an example of a gas analyzer using a laser according to the present invention. As shown in the drawing, an optical window 6 with a purge 5 is provided in a pipe 1 for transporting gas, and a lens 4, a mirror 8, a plasma laser 3 and a component excitation laser 7 are arranged outside the optical window 6. Has been done.

The plasma laser 3 is a laser for generating plasma, and is focused on the measured field 2 in the pipe 1 through the lens 4 and the optical window 5 so that the gas, liquid, The solid is turned into plasma.

The component excitation laser 7 is a laser which generates a wavelength corresponding to the excitation wavelength of the component to be measured in the substance,
The component to be measured in the laser-induced plasma is made to fluoresce by being incident on the measured field 2 in the pipe 1 in synchronization with the laser 3 for plasma through the mirror 8, the lens 4 and the optical window 5. The fluorescence emitted by the component to be measured excited by the plasma emission and the component excitation laser 7 is condensed by the lens 10 via the optical window 5 and the mirror 9, and the spectroscope 11
And is detected by the CCD camera 12.

The respective signals are transferred to the computer 13, the component composition of the measured field 2 and the plasma temperature are obtained from the plasma emission signal, and the fluorescence intensity is corrected from the information, and the signals are present in the measured field 2. Calculate the concentrations of trace constituents. The oscillations of the plasma laser 3 and the component excitation laser 7 and the CCD camera 12 are synchronized by the line 14.

Embodiment 1 FIG. 1 shows an embodiment of the gas direct analysis method according to the present invention. As shown in the figure, from the gas pipe 15 to the measurement pipe 1
6 is branched and a closed container 21 is connected to the measurement pipe 16 via a shutoff valve 17, and a flange 1 having a laser optical window 18 is provided between the shutoff valve 17 and the closed container 21.
9 are doubly interposed.

A gas analyzer 20 using a laser including a plasma laser 3, a component excitation laser 7 and a spectroscope 11 shown in FIG. 2 is hermetically installed in a closed container 21. The laser optical window 18 is made of a visible material (for example, glass), and the central portion of the flange 19 allows laser light to pass therethrough, but does not allow gas or the like to pass therethrough and has a hermeticity.

A space 22 sealed by the laser optical window 18 is provided between the two flanges 19. A pressure gauge 25 is connected to the space 22 and an atmosphere discharge line 24 is connected to the space 22. The air release line 24 is equipped with a shutoff valve 23. The pressure in the space 22 is measured by the pressure gauge 25.

Therefore, at the time of gas analysis, the shutoff valve 17 is opened, the gas is passed from the gas pipe 15 to the front part of the laser optical window 18, and plasma is generated in this part for analysis. When the gas leaks from the measurement pipe 16 to the space 22 side during the gas analysis and the pressure in the space 22 is reduced by the pressure gauge 25, and when the differential pressure between the pipe 15 and the pressure reaches a certain level or more, promptly Then, the plasma generation is stopped and the shutoff valve 17 of the measurement pipe 16 is closed. Further, the shutoff valve 23 of the atmosphere release line 24 is opened to release the leak gas in the space 22 to the outside of the system.

As described above, since the gas analyzer 20 is an optical device, it is vulnerable to thermal influences, and is also affected by pressure, which may cause irreparable trouble. Gas analysis at pressure is desirable. Therefore, in the present embodiment, in order to prevent the temperature rise or pressure rise of the gas analyzer 20,
A measurement pipe 16 is branched from the gas pipe 15, and a gas analyzer 20 is connected to this. In addition, the gas analyzer 2
In order to avoid contact between 0 and gas, the laser optical window 18 is doubled.

However, since the laser optical window 18 has a weaker sealing performance than the shutoff valve 17, gas leakage may occur and the gas analyzer 20 may be irreparably affected.
Therefore, when it is detected that the gas leaks into the space 22 sandwiched between the double laser optical windows 18, the leak gas is promptly discharged out of the system so that the leak gas does not come into contact with the gas analyzer 20. There is. This makes it possible to reliably prevent damage to the gas analyzer 20 due to gas leakage.

Example 2 An example of the gas direct analysis method according to the present invention is shown in FIG. As shown in the figure, from the gas pipe 15 to the measurement pipe 1
6 is branched and a closed container 21 is connected to the measurement pipe 16 via a shutoff valve 17, and a flange 1 having a laser optical window 18 is provided between the shutoff valve 17 and the closed container 21.
9 are doubly interposed.

A gas analyzer 20 using a laser including a plasma laser 3, a component excitation laser 7 and a spectroscope 11 shown in FIG. 2 is hermetically installed in the closed container 21. The laser optical window 18 is made of a visible material (for example, glass), and the central portion of the flange 19 allows laser light to pass therethrough, but does not allow gas or the like to pass therethrough and has a hermeticity.

A space 22 sealed by the laser optical window 18 is provided between the two flanges 19, and a differential pressure gauge 26 and an atmosphere discharge line 24 are connected to the space 22. The air release line 24 is equipped with a shutoff valve 23. The differential pressure between the space 22 and the pipe 15 is measured by a differential pressure gauge 26.

Therefore, at the time of gas analysis, the shutoff valve 17 is opened, gas is passed from the gas pipe 15 to the front part of the laser optical window 18, and plasma is generated in this part for analysis. When the gas leaks from the measurement pipe 16 to the space 22 during the gas analysis, the pressure in the space 22 is reduced, and the differential pressure with the pipe 15 reaches a certain level or more by the differential pressure gauge 26, The plasma conversion is stopped immediately and the shutoff valve 17 of the measurement pipe 16 is closed. Further, the shutoff valve 23 of the atmosphere release line 24 is opened to release the leak gas in the space 22 to the outside of the system.

As described above, since the gas analyzer 20 is an optical device, it is vulnerable to thermal influences, and is also affected by pressure, which may cause irreparable troubles. Gas analysis at pressure is desirable. Therefore, in the present embodiment, in order to prevent the temperature rise or pressure rise of the gas analyzer 20,
A measurement pipe 16 is branched from the gas pipe 15, and a gas analyzer 20 is connected to this. In addition, the gas analyzer 2
In order to avoid contact between 0 and gas, the laser optical window 18 is doubled.

However, since the laser optical window 18 has a weaker sealing performance than the shutoff valve 17, gas leakage may occur and the gas analyzer 20 may be irreparably affected.
Therefore, when it is detected that gas has leaked into the space 22 sandwiched between the double laser optical windows 18, the leak gas is promptly discharged to the outside of the system so that the leak gas does not come into contact with the gas analyzer 20. There is. This makes it possible to reliably prevent damage to the gas analyzer 20 due to gas leakage.

[Embodiment 3] FIG. 4 shows an embodiment of the gas direct analysis method according to the present invention. As shown in the figure, from the gas pipe 15 to the measurement pipe 1
6 is branched and a closed container 21 is connected to the measurement pipe 16 via a shutoff valve 17, and a flange 1 having a laser optical window 18 is provided between the shutoff valve 17 and the closed container 21.
9 are doubly interposed.

A gas analyzer 20 using a laser including a plasma laser 3, a component excitation laser 7 and a spectroscope 11 shown in FIG. 2 is hermetically installed in the closed container 21. The laser optical window 18 is made of a visible material (for example, glass), and the central portion of the flange 19 allows laser light to pass therethrough, but does not allow gas or the like to pass therethrough and has a hermeticity.

A space 22 sealed by the laser optical window 18 is provided between the two flanges 19, and a thermometer 27 is connected to the space 22 and an atmosphere emission line 24 is connected thereto. The air release line 24 is equipped with a shutoff valve 23. The temperature of the space 22 is measured by a thermometer 27.

Therefore, at the time of gas analysis, the shutoff valve 17 is opened, gas is passed from the gas pipe 15 to the front part of the laser optical window 18, and plasma is generated in this part for analysis. When gas leaks from the measurement pipe 16 to the space 22 side during the gas analysis, the temperature of the space 22 decreases, and the temperature reaches a predetermined temperature by the thermometer 27, it is promptly turned into plasma. The measurement is stopped, and the shutoff valve 17 of the measurement pipe 16 is closed. Further, the shutoff valve 23 of the atmosphere release line 24 is opened to release the leak gas in the space 22 to the outside of the system.

As described above, since the gas analyzer 20 is an optical device, it is vulnerable to thermal influences, and is also affected by pressure, which may cause irreparable troubles, so that it is normal at room temperature. Gas analysis at pressure is desirable. Therefore, in the present embodiment, in order to prevent the temperature rise or pressure rise of the gas analyzer 20,
A measurement pipe 16 is branched from the gas pipe 15, and a gas analyzer 20 is connected to this. In addition, the gas analyzer 2
In order to avoid contact between 0 and gas, the laser optical window 18 is doubled.

However, since the laser optical window 18 has a weaker sealing performance than the shutoff valve 17, gas leakage may occur and the gas analyzer 20 may be irreparably affected.
Therefore, when it is detected that the gas leaks into the space 22 sandwiched between the double laser optical windows 18, the leak gas is promptly discharged out of the system so that the leak gas does not come into contact with the gas analyzer 20. There is. This makes it possible to reliably prevent damage to the gas analyzer 20 due to gas leakage.

[0028]

As described above in detail with reference to the embodiments, in the present invention, two laser optical windows are provided, and a pressure gauge or a pressure differential pressure gauge is provided in the space partitioned by the laser optical windows. Te, for determining that gas leakage by detecting a pressure change, when the gas leakage becomes constant or stops the measurement (plasma generation), closes the front of the shut-off valve, and further, the air opens the leak gas Since the gas is released to the line, the safety of the gas analyzer using the laser is ensured, which contributes to the improvement of the reliability of the measuring device.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a safety device of a direct gas analyzer according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a gas analyzer using a laser according to the present invention.

FIG. 3 is an explanatory diagram showing a safety device of a direct gas analyzer according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a safety device of a gas direct analyzer according to a third embodiment of the present invention.

[Explanation of symbols]

1 piping 2 measurement site 3 Laser for plasma 4,10 lens 5 Purge 6 Optical window Laser for 7-component excitation 8,9 mirror 11 Spectrometer 12 CCD camera 13 Computer 14 lines 15 gas piping 16 Measuring branch pipe 17,23 Shut-off valve 18 Laser optical window 19 flange 20 Gas analyzer using laser 21 sealed container 22 space 24 atmosphere open line 25 pressure gauge 26 Differential pressure gauge 27 Thermometer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographic references Sho 58-170537 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 21/00-21/61 G01N 21 / 62-21/74 PATOLIS

Claims (4)

(57) [Claims] 1. A measuring pipe is branched from a pipe of a gas to be measured whose pressure is atmospheric pressure or more, and a closed container containing a gas analyzer using a laser is connected to the measuring pipe, and further, In a method for directly analyzing a gas in which a measurement pipe is provided with a flange provided with a shutoff valve and a laser optical window, the flange provided with the laser optical window is doubled, and two laser optical windows are provided. Due to the increase of the internal pressure in the space partitioned by the flange, the gas leak from the measuring pipe is detected, and if the gas leak is detected, the laser is quickly detected by the gas analyzer using the laser. A method for direct analysis of gas, which comprises stopping and closing a shutoff valve installed in the measuring pipe. 2. A measuring pipe is branched from a pipe of a gas to be measured having a pressure equal to or higher than atmospheric pressure, and a closed container accommodating a gas analyzer using a laser is connected to the measuring pipe. In a method for directly analyzing a gas in which a measurement pipe is provided with a flange provided with a shutoff valve and a laser optical window, the flange provided with the laser optical window is doubled, and two laser optical windows are provided. Due to the decrease in the differential pressure between the space partitioned by the flange and the measurement pipe, a gas leak from the measurement pipe is detected, and when a gas leak is detected, the gas is analyzed using the laser. A method for direct analysis of gas, characterized in that the laser by the device is quickly stopped and the shutoff valve installed in the measurement pipe is closed.
Law . 3. A measuring pipe is branched from a pipe of a gas to be measured whose pressure is atmospheric pressure or more, and a closed container containing a gas analyzer using a laser is connected to the measuring pipe. In a method for directly analyzing a gas in which a measurement pipe is provided with a flange provided with a shutoff valve and a laser optical window, the flange provided with the laser optical window is doubled, and two laser optical windows are provided. A line that opens the atmosphere by connecting a shutoff valve to the space partitioned by the flange is detected, and a gas leak from the measurement pipe is detected due to an increase in the internal pressure in the space, and a gas leak is detected. In the case of the gas, the laser by the gas analyzer using the laser is quickly stopped, the shutoff valve installed in the measurement pipe is closed, and the shutoff valve of the atmosphere release line is opened. direct analysis of Law. 4. A measurement pipe is branched from a pipe of a gas to be measured whose pressure is atmospheric pressure or more, and a closed container containing a gas analyzer using a laser is connected to the measurement pipe, and further, In a method for directly analyzing a gas in which a measurement pipe is provided with a flange provided with a shutoff valve and a laser optical window, the flange provided with the laser optical window is doubled, and two laser optical windows are provided. Connecting a line that opens the atmosphere by meeting a shutoff valve in a space partitioned by a flange, and detects a gas leak from the measurement pipe due to a decrease in differential pressure between the space and the measurement pipe, When a gas leak is detected, the laser by the gas analyzer using the laser is immediately stopped, the shutoff valve installed in the measurement pipe is closed, and the shutoff valve of the atmosphere release line is opened. Characterized by Direct analysis method of gas.