Continuous gas analysis system and continuous gas analysis method

Abstract

The present invention provides a continuous gas analysis system and a continuous gas analysis method for shortening the time for calibration or verification of an analyzer for analyzing a sample gas containing an adsorptive component, the continuous gas analysis system comprising: a main flow path through which the sample gas containing the adsorptive component flows; an analyzer for analyzing an adsorptive component in the sample gas flowing through the main flow path; a standard gas flow path for supplying a standard gas for calibration or verification to the analyzer; and a purge gas flow path that supplies a purge gas containing moisture to the analyzer, introduces the sample gas into the main flow path, continuously analyzes the sample gas by the analyzer, supplies the purge gas from the purge gas flow path to the analyzer during the continuous analysis, and purges the analyzer. Standard gas is supplied from the standard gas flow path to the analyzer to correct or verify the analyzer.

Description

Technical Field

[0001] The invention relates to a gas continuous analysis system and a gas continuous analysis method. Background Art

[0002] In the past, as a method for continuously analyzing gases (e.g., flue gas or process gas) discharged from industrial equipment such as industrial waste treatment sites or chemical plants, the gas was sampled and introduced into an analyzer. In addition, the analyzer was calibrated (zero point calibration, span calibration) in the middle of the continuous analysis. In addition, zero point calibration was performed using a zero point gas such as nitrogen (N2) gas, and span calibration was performed using a span gas containing a measurement component with a known concentration.

[0003] However, when analyzing an adsorbent component such as hydrogen fluoride (HF) or hydrogen chloride (HCl) contained in a gas, the adsorbent component is adsorbed on the inner surface of the pipe or the measuring cell of the analyzer. When a zero-point gas is passed during calibration, the adsorbent component adsorbed in the cell is separated from the measuring cell. Therefore, it takes time for the indicated value of the analyzer to stabilize during calibration. As a result, the calibration time during the interval of continuous analysis becomes longer, and the interruption time in the continuous analysis of the gas becomes longer.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2013-96889 Summary of the invention

[0005] Therefore, the present invention has been made to solve the above-mentioned problems, and a main object of the present invention is to shorten the time required for calibration or verification of an analyzer that analyzes a sample gas containing an adsorptive component.

[0006] That is, the gas continuous analysis system of the present invention includes: a mainstream path, through which a sample gas containing adsorptive components flows; an analyzer, which analyzes the adsorptive components in the sample gas flowing in the mainstream path; a standard gas path, which supplies a standard gas for calibration or verification to the analyzer; and a purge gas path, which supplies a purge gas containing moisture to the path of the analyzer through which the sample gas passes, the sample gas is introduced into the mainstream path and the sample gas is continuously analyzed by the analyzer, the purge gas is supplied from the purge gas path to the analyzer in the middle of the continuous analysis to purge the path of the analyzer through which the sample gas passes, and then, the standard gas is supplied from the standard gas path to the analyzer to calibrate or verify the analyzer.

[0007] According to such a gas continuous analysis system, before calibrating or verifying the analyzer, the flow path through which the sample gas passes of the analyzer is purged with a purge gas containing water, thereby shortening the time until the indicated value of the analyzer becomes stable during calibration or verification. Here, since the purge gas containing water is used, the adsorbent components adsorbed on the inner surface of the flow path through which the sample gas passes, such as a measuring cell of the analyzer, are easily detached by water molecules. As a result, the time for calibration or verification performed between continuous analysis can be shortened, and the interruption time in the continuous analysis of the sample gas can be shortened.

[0008] As a specific embodiment of the purge gas flow path, it is conceivable to supply the atmospheric air to the flow path of the analyzer through which the sample gas passes. With this configuration, the cost of the purge gas can be reduced.

[0009] As a specific embodiment of the analyzer, it is possible to analyze HF, HCl or NH3 as the adsorbent component. Here, the dipole moment as an indicator of adsorption ease is H2O>HF>NH3>HCl. In a system for analyzing HF, HCl or NH3 as an adsorbent component, the effect of using a purge gas containing water can be significantly improved.

[0010] It is considered that the standard gas flow path includes a zero calibration gas flow path for supplying a zero calibration gas to the analyzer and a span calibration gas flow path for supplying a span calibration gas to the analyzer. In the structure, in order to shorten the correction time of zero point calibration and the correction time of span calibration, the gas continuous analysis system is ideally: in the middle of the continuous analysis, the purge gas is supplied from the purge gas flow path to the analyzer to purge the flow path of the analyzer through which the sample gas passes; then, the zero point calibration gas is supplied from the zero point calibration gas flow path to the analyzer to perform zero point calibration on the analyzer; and the span calibration gas is supplied from the span calibration gas flow path to the analyzer to perform span calibration on the analyzer.

[0011] The standard gas flow path may also be configured to have a structure that does not include a zero point calibration gas flow path for supplying a zero point calibration gas to the analyzer. In this case, it is ideal that: the standard gas flow path supplies a span calibration gas to the analyzer, and in the gas continuous analysis system, the purge gas is supplied from the purge gas flow path to the analyzer in the middle of the continuous analysis to purge the flow path of the analyzer through which the sample gas passes, and the analyzer is zero-calibrated, and then the span calibration gas is supplied from the standard gas flow path to the analyzer to perform a span calibration on the analyzer. According to the above configuration, the zero point calibration can be performed by supplying the purge gas from the purge gas flow path without using the zero point calibration gas flow path.

[0012] The main flow path can be purged on the downstream side of the connection point of the purge gas flow path. However, the main flow path cannot be purged on the upstream side of the connection point of the purge gas flow path. Therefore, the exhaust gas will be retained after the continuous analysis is completed, and the moisture in the exhaust gas will condense. This will become a major cause of measurement error in the subsequent continuous analysis. In order to solve the problem well, it is ideal that: the gas continuous analysis system of the present invention also includes a second purge flow path, the second purge flow path is connected to the upstream side of the analyzer in the main flow path, and the second purge gas is supplied from the connection point toward the upstream side of the main flow path. In the exhaust gas continuous analysis system, after the continuous analysis is completed, the second purge gas is supplied from the second purge flow path to purge the upstream side of the connection point of the second purge flow path.

[0013] When analyzing adsorbent components such as HF, HCl, or NH 3 , the adsorbent components are adsorbed on the inner surface of the pipe constituting the main flow path, and the response time of the analyzer becomes slow. In order to satisfactorily solve the above problem, it is desirable to further include an overflow flow path for discharging a part of the sample gas flowing in the main flow path on the upstream side of the analyzer. According to the above structure, the flow rate of the sample gas introduced into the main flow path can be increased through the overflow flow path. As a result, the adsorptive component can be less likely to be adsorbed on the inner surface of the pipe constituting the main flow path.

[0014] As a structure for shortening the distance from the overflow flow path to the analyzer, it is ideal that: a throttling portion is provided between the connection point of the overflow flow path in the main flow path and the analyzer, a main suction pump is provided on the downstream side of the analyzer in the main flow path, and an auxiliary suction pump is provided in the overflow flow path.

[0015] In addition, the gas continuous analysis system of the present invention includes: a sampling unit for sampling a gas containing adsorptive components flowing in a pipeline; a mainstream path for the flow of the sample gas sampled by the sampling unit; a chromatograph or a mass analyzer for analyzing the adsorptive components in the sample gas flowing in the mainstream path; and an overflow path for discharging a portion of the sample gas flowing in the mainstream path on the upstream side of the analyzer. With the above structure, the sample gas introduced into the main flow path can be made larger in flow rate through the overflow flow path. As a result, the adsorptive components are less likely to be adsorbed on the inner surface of the pipe constituting the main flow path, and the analysis accuracy using the chromatograph or mass analyzer can be improved. In addition, it also helps to improve the response time of the chromatograph or mass analyzer.

[0016] Furthermore, the gas continuous analysis method of the present invention is a gas continuous analysis method using a measuring system, the measuring system comprising: a mainstream path, for a sample gas containing adsorptive components to flow; an analyzer, for analyzing adsorptive components in the sample gas flowing in the mainstream path; a standard gas path, for supplying a standard gas for calibration or verification to the analyzer; and a purge gas path, for supplying a purge gas containing moisture to a path of the analyzer through which the sample gas passes, wherein the sample gas is introduced into the mainstream path and the sample gas is continuously analyzed by the analyzer, and in the middle of the continuous analysis, the purge gas is supplied from the purge gas path to the analyzer to purge the path of the analyzer through which the sample gas passes, and then, the standard gas is supplied from the standard gas path to the analyzer to calibrate or verify the analyzer.

[0017] According to the present invention thus constituted, it is possible to shorten the time required for calibration or verification of an analyzer that analyzes a sample gas containing an adsorptive component. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram showing a gas continuous analysis system according to one embodiment of the present invention. Figure 2 It is a schematic diagram showing the structure inside a housing that houses the analyzer according to the above embodiment. Figure 3 It is a schematic diagram showing the flow of sample gas during continuous analysis in the above-mentioned embodiment. Figure 4 It is a schematic diagram showing the flow of the purge gas (atmospheric air) during the purge process in the above-mentioned embodiment. Figure 5 It is a schematic diagram showing the flow of the zero point gas during the zero point calibration in the above embodiment. Figure 6 It is a schematic diagram showing the flow of the span gas during the span calibration in the above-mentioned embodiment. Figure 7 This is a schematic diagram showing the flow of the second purge gas after the continuous analysis of the embodiment is completed (before or during the system stop). Figure 8 It is a schematic diagram showing a gas continuous analysis system according to a modified embodiment. Fig. 9It is a schematic diagram showing a gas continuous analysis system according to a modified embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, one embodiment of the gas continuous analysis system of the present invention will be described with reference to the drawings. In addition, for the sake of easy understanding, the following drawings are schematically depicted with appropriate omissions or exaggerations. The same components are denoted by the same reference numerals, and the description thereof is appropriately omitted.

[0020] The gas continuous analysis system 100 of the present embodiment is a system that continuously analyzes the concentration of adsorptive components such as hydrogen fluoride (HF), hydrogen chloride (HCl), or ammonia (NH 3 ) in a sample gas.

[0021] Here, the sample gas is a combustion gas such as a burning gas or a combustion exhaust gas (flue exhaust) or a process gas. The burning gas refers to a gas burning in an external combustion engine, an industrial furnace, an incinerator, a turbine or a power station, and the combustion exhaust gas refers to a gas discharged from an external combustion engine, an industrial furnace, an incinerator, a turbine or a power station after combustion. In addition, the process gas refers to a gas in a chemical equipment such as petrochemicals, coal chemistry, natural gas chemistry, petroleum refining, methanation, and a gasifier. In addition to raw gas such as natural gas, it also includes a gas separated in a chemical equipment or a gas generated in a chemical equipment. Furthermore, the process gas includes a gas that has passed through a scrubber or the like as an exhaust gas treatment equipment of a semiconductor manufacturing plant (semiconductor manufacturing device), for example, the exhaust gas from an etching device is passed through a scrubber that removes HF generated in a decomposition reaction from the exhaust gas and then passes through the scrubber. In addition, the gas after the various gases are detoxified can also be set as the sample gas.

[0022] Specifically, if Figure 1 As shown, the gas continuous analysis system 100 includes: a mainstream path 2, for supplying a sample gas containing adsorptive components; an analyzer 3, for analyzing the adsorptive components in the sample gas flowing in the mainstream path 2; a calibration gas path 4 as a standard gas path, for supplying a calibration gas as a standard gas to the analyzer 3; a purge gas path (first purge gas path) 5A, for supplying a purge gas (first purge gas) containing moisture to the path for supplying sample gas to the analyzer 3; a second purge gas path 5B, which is connected to the upstream side of the analyzer 3 in the mainstream path 2 and supplies the second purge gas from the connection point toward the upstream side of the mainstream path 2; and an overflow path 6, for discharging a portion of the sample gas flowing in the mainstream path 2 at the upstream side of the analyzer 3.

[0023] A sampling section 7 is provided at one end of the main flow path 2, and the sampling section 7 is used, for example, to sample the gas flowing in the flue. The sampling section 7 has a sampling probe 7P, and the sampling probe 7P is inserted into the flue formed by the pipe D, and the gas is sampled from the sampling probe 7P. In addition, a dust filter 71 is provided in the sampling section 7. Moreover, the main flow path 2 is composed of a hot hose 21 from the sampling section 7 to the frame 8 that accommodates the analyzer 3. In addition, the hot hose 21 can also prevent the adsorption of adsorbent components by using a hot hose made of Teflon. In addition, in Figure 2 In the figure, reference numeral 8F denotes a ventilation unit such as a fan provided on the wall of the housing 8 .

[0024] Specifically, in the main flow path 2, on the downstream side of the hot hose 21, a dust filter 2a, a throttling part 2b such as a throttling hole, an analyzer 3, and a main suction pump 2c are arranged in order from the upstream side. In addition, in the main flow path 2, an electromagnetic on-off valve 2d is arranged on the upstream side of the dust filter 2a. In addition, in the main flow path 2, a pressure sensor 2e, a flow sensor 2f, a check valve 2g, or a pressure regulating valve 2h, etc. can also be arranged between the analyzer 3 and the main suction pump 2c. In this embodiment, the pressure regulating valve 2h and the main suction pump 2c are configured to be arranged outside the frame 8. Furthermore, the piping on the downstream side of the main suction pump 2c in the main flow path 2 can also be heated so that moisture does not condense. Here, the heating temperature can be set according to the moisture concentration in the sample gas. When the moisture concentration in the sample gas is, for example, 6 vol%, it can be considered to set the heating temperature to, for example, 40°C. In addition, a dehumidifier or buffer container may be provided downstream of the main suction pump 2c to remove moisture from the sample gas. In addition, the upstream side of the main suction pump 2c is depressurized and does not need to be heated, but it may be heated and a dehumidifier or buffer container may be provided.

[0025] The analyzer 3 continuously analyzes the concentration of HF, HCl or NH3 as adsorptive components in the sample gas, for example, using an IRLAM (infrared laser absorption modulation) detector which utilizes the infrared laser absorption modulation method (see Japanese Patent No. 6886507).

[0026] Specifically, if Figure 1 and Figure 2As shown, the analyzer 3 includes: a measuring cell 31, into which the sample gas is introduced; a semiconductor laser 32, which irradiates the measuring cell 31 with laser light; a photodetector 33, which receives the laser light that has passed through the measuring cell 31; and a signal processing unit 34, which receives the output signal of the photodetector 33 and calculates the concentration of the measured component based on the value thereof. In addition, the measuring cell 31 is a so-called Herriott cell, which has an inlet port P1 for introducing the sample gas and an outlet port P2 for exporting the sample gas, and a pair of reflectors M1 and M2 are provided inside to perform multiple reflections on the laser light. In addition, the measuring cell 31 is temperature-controlled to a predetermined temperature based on the detection temperature of the temperature sensor 35. Furthermore, the concentration of the measured component obtained by the signal processing unit 34 is displayed on a display unit 10 such as a display.

[0027] Here, as the semiconductor laser 32 , a quantum cascade laser, an interband cascade laser, or a semiconductor laser other than these can be used.

[0028] A quantum cascade laser is a semiconductor laser that uses inter-subband transitions based on a multi-level quantum well structure, and oscillates lasers of a specific wavelength in the wavelength range of about 4μm to about 20μm. In addition, an inter-band cascade laser is a semiconductor laser that uses inter-band transitions based on a multi-level PN junction of a quantum well structure, and oscillates lasers of a specific wavelength in the wavelength range of about 3μm to about 5μm. Furthermore, other semiconductor lasers are semiconductor lasers that use inter-band transitions based on a single PN junction of a quantum well structure, and are semiconductor lasers that can mainly oscillate ultraviolet light, visible light, and near-infrared light in the range of 0.3μm to 3μm.

[0029] Furthermore, if Figure 2 As shown, the semiconductor laser 32 may also be configured to include a plurality of semiconductor lasers 32. In this case, the plurality of semiconductor lasers 32 may be configured to emit lasers of different wavelengths according to the measurement components. Here, the plurality of semiconductor lasers 32 may be configured to emit lasers at different times from each other, or may be configured so that at least two or more semiconductor lasers 32 emit lasers at the same time. In addition, there may also be a plurality of reflectors 36a to 36h for introducing the lasers respectively emitted from the plurality of semiconductor lasers 32 into the measurement cell 31. In addition, the lasers emitted through the measurement cell 31 are reflected by the reflector 36i and detected by the light detector 33. In addition, in Figure 2 In the figure, the reference numeral 8X abbreviates a piping system (main flow path 2, calibration gas flow path 4, first purge gas flow path 5A, second purge flow path 5B or overflow flow path 6, etc.) which is arranged in the frame 8 and is used to introduce sample gas, purge gas or calibration gas, etc. into the measuring cell 31.

[0030] The calibration gas flow path 4 is connected to the upstream side of the analyzer 3 in the main flow path 2, and supplies calibration gas to the main flow path 2. The calibration gas flow path 4 of this embodiment is connected to the upstream side of the dust filter 2a in the main flow path 2, specifically, is connected between the electromagnetic on-off valve 2d and the dust filter 2a.

[0031] Specifically, the calibration gas flow path 4 includes: a zero point gas flow path 41 for supplying a zero point gas such as N2 gas to the analyzer 3; and a range gas flow path 42 for supplying a range gas of known concentration to the analyzer 3. In the present embodiment, the zero point gas flow path 41 and the range gas flow path 42 merge with each other and are connected to the main flow path 2. In addition, the range gas flow path 42 may also be provided with a plurality of ( Figure 1 In the calibration gas flow paths 41 and 42, electromagnetic on-off valves 41a and 42a are provided to switch the supply of each calibration gas. In addition, pressure regulating valves 41b and 42b and needle valves 41c and 42c for flow rate adjustment may be provided to each calibration gas flow path 41 and 42.

[0032] The first purge gas flow path 5A is connected to the upstream side of the analyzer 3 in the main flow path 2, and supplies the first purge gas containing moisture to the main flow path 2, and supplies the first purge gas containing moisture to the flow path for sample gas flow of the analyzer 3. The first purge gas flow path 5A of this embodiment supplies the atmosphere as the first purge gas containing moisture to the flow path for sample gas flow of the analyzer 3. Therefore, a dust filter 51 is provided in the atmosphere introduction part 50 of the first purge gas flow path 5A. The first purge gas flow path 5A is connected to the upstream side of the dust filter 2a in the main flow path 2, specifically, it is connected between the electromagnetic opening and closing valve 2d and the dust filter 2a. In addition, the first purge gas flow path 5A merges with the calibration gas flow path 4 and is connected to the main flow path 2. As a result, the first purge gas flow path 5A also supplies the atmosphere as the first purge gas to the calibration gas flow path 4. Here, the electromagnetic opening and closing valve 5a is provided in the first purge gas flow path 5A, which is configured to switch the supply of the first purge gas.

[0033] The second purge gas flow path 5B is connected to the upstream side of the analyzer 3 in the main flow path 2, and the second purge gas is supplied to the main flow path 2, and the second purge gas is supplied to the upstream side more than the connection point of the second purge gas flow path 5B. The second purge gas of this embodiment flows back to the main flow path 2, purges the exhaust gas retained in the main flow path 2 and discharges it to the outside from the sampling unit 7. In addition, although not shown in the figure, a second purge gas source (not shown) for pressurizing the second purge gas is connected to the upstream side of the second purge gas flow path 5B. Here, dry air or nitrogen can be used for the second purge air. Specifically, the second purge air flow path 5B is connected to the upstream side of the electromagnetic on-off valve 2d in the main flow path 2. In addition, a three-way valve 2i is provided at the connection point of the second purge gas flow path 5B in the main flow path 2. The three-way valve 2i can be a manual switching valve or an electromagnetic switching valve. In addition, the electromagnetic on-off valve 2d of the main flow path 2 can also be set as a three-way valve, and the electromagnetic on-off valve 2d is connected to the second purge gas flow path 5B.

[0034] The overflow flow path 6 is connected to the upstream side of the analyzer 3 in the main flow path 2, and a part of the sample gas flowing in the main flow path 2 is discharged. Here, the upstream side of the dust filter 2a connected to the main flow path 2 is specifically connected between the electromagnetic opening and closing valve 2d and the dust filter 2a. That is, only the dust filter 2a and the throttling part 2b are provided between the connection point 6x of the overflow flow path 6 and the analyzer 3, and the distance from the connection point 6x of the overflow flow path 6 to the analyzer 3 is shortened as much as possible. In addition, a secondary suction pump 6a can also be provided in the overflow flow path 6, a needle valve 6b for flow adjustment can be provided on the upstream side of the secondary suction pump 6a, and a flow sensor 6c can be provided on the downstream side of the secondary suction pump 6a. In this embodiment, the secondary suction pump 6a, the needle valve 6b and the flow sensor 6c are configured to be provided outside the frame 8. In addition, in this embodiment, the piping outside the frame 8 in the overflow flow path 6 can also be heated to prevent moisture from condensing. Here, the heating temperature can be set according to the water concentration in the sample gas. When the water concentration in the sample gas is, for example, 6 vol%, the heating temperature can be set to, for example, 40° C. In addition, a dehumidifier or a buffer container can be provided in the piping outside the frame 8 in the overflow flow path 6 to remove the water in the sample gas.

[0035] Furthermore, a bypass passage 9 that bypasses the auxiliary suction pump 6a is connected to the overflow passage 6. In addition, a three-way solenoid valve 6d is provided at the connection point on the upstream side of the overflow passage 6 and the bypass passage 9, so as to be able to switch these passages. In addition, a check valve 6e may be provided on the upstream side of the three-way solenoid valve 6d in the overflow passage 6. In addition, in the present embodiment, the piping outside the frame 8 in the bypass passage 9 may also be heated to prevent moisture from condensing. Here, the heating temperature may be set according to the moisture concentration in the sample gas. When the moisture concentration in the sample gas is, for example, 6 vol%, it may be considered to set the heating temperature to, for example, 40°C. In addition, a dehumidifier or a buffer container may also be provided in the piping outside the frame 8 in the bypass passage 9 to remove moisture from the sample gas.

[0036] In addition, the piping inside the frame 8 in the main flow path 2, the overflow flow path 6, or the bypass flow path 9 may be heated to prevent moisture from condensing. Specifically, in the main flow path 2, the piping connected to the hot hose 21 may be heated up to the orifice 2b. Here, the downstream side of the orifice 2b is depressurized by the main suction pump 2c, and heating is not necessary. In addition, it may be configured to locally heat a portion that is prone to condensation according to conditions such as measurement conditions or usage conditions.

[0037] In addition, the gas continuous analysis system 100 of the present embodiment continuously analyzes corrosive gases such as hydrogen fluoride (HF) or hydrogen chloride (HCl) in the sample gas, so the flow path for the sample gas to flow can also be formed by a material that is resistant to corrosion of the corrosive gas. For example, Teflon tubes or stainless steel tubes (such as SUS316L) can also be used to form the piping constituting the main flow path 2, the piping constituting the overflow flow path 6 and / or the piping constituting the bypass flow path 9. In the case of using stainless steel tubes, it is possible to consider using stainless steel tubes with polished inner surfaces. In addition, in order to facilitate the processing of the piping, it is ideal to use Teflon tubes. In addition, the measuring cell 31 can also be formed by a material that is resistant to corrosion of corrosive gases. For example, it is possible to consider setting the measuring cell 31 to stainless steel (such as SUS316L, etc.), and setting the reflectors M1 and M2 disposed inside the measuring cell 31 to stainless steel (such as SUS316L, etc.) with gold plating applied to the reflecting surface. The above-mentioned members may be made of Hastelloy, Inconel, or the like in addition to stainless steel.

[0038] <Operation of the Gas Continuous Analysis System 100> Below, refer to Figure 3 to Figure 7 The operation of the gas continuous analysis system 100 according to the present embodiment will be described. The gas continuous analysis method is implemented by the operation of the gas continuous analysis system 100 .

[0039] <General Analysis> In the usual continuous analysis, such as Figure 3 As shown, the sampling gas of the total flow rate of the suction flow rate of the main suction pump 2c provided in the main flow path 2 and the suction flow rate of the auxiliary suction pump 6a provided in the overflow flow path 6 is sampled from the sampling section 7. Moreover, a part of the sample gas flowing in the main flow path 2 is introduced into the analyzer 3 through the dust collecting filter 2a and the throttle section 2b. The other sample gas is discharged through the overflow flow path 6. In addition, the sample gas sucked by the main suction pump 2c and introduced into the analyzer 3 through the throttle section 2b is a constant flow rate, and the inside of the measuring cell 31 is in a decompressed state. In this state, the concentration of HF or HCl as an adsorbent component is continuously analyzed by the analyzer 3.

[0040] <Calibration (including purging)> During the continuous analysis, a calibration process is periodically performed, for example, based on a predetermined schedule. Also, a first purge process is performed before the calibration process.

[0041] Specifically, if Figure 4 As shown, the first purge gas is supplied from the first purge gas flow path 5A to the analyzer 3, and the flow path for sample gas flow and a part of the calibration gas flow path 4 of the analyzer 3 are purged. Here, the flow path for sample gas flow is the flow path from the sample gas inlet port (not shown) of the analyzer 3 to the flow path passing through the measuring cell 31. In addition, a part of the calibration gas flow path 4 is the downstream side part from the confluence point where the first purge gas flow path 5A and the calibration gas flow path 4 merge. At this time, the electromagnetic on-off valve 2d of the main flow path 2 is closed, and the electromagnetic on-off valve 5a of the first purge gas flow path 5A is opened. In this state, the atmosphere containing moisture is introduced from the atmosphere inlet part 50 of the first purge gas flow path 5A through the main suction pump 2c, and the atmosphere containing moisture is introduced into the measuring cell 31 of the analyzer 3. Thus, the adsorptive components adsorbed on the inner surface of the pipe from the connection point of the first purge gas flow channel 5A in the main flow channel 2 to the measuring cell 31 , the inner surface of the measuring cell 31 , and the reflecting mirrors M1 and M2 are removed by desorption of water molecules.

[0042] After the first purging process, calibration gas is supplied from the calibration gas flow path 4 to the analyzer 3 to calibrate the analyzer 3. That is, the analyzer 3 is calibrated in the purged state.

[0043] First, if Figure 5As shown, zero-point calibration is performed by supplying zero-point gas from the zero-point gas flow path 41 to the analyzer 3. Here, the electromagnetic on-off valve 2d of the main flow path 2 is closed, and the electromagnetic on-off valve 41a of the zero-point gas flow path 41 is opened. In this state, the zero-point gas is introduced from the zero-point gas flow path 41 to the measuring cell 31 of the analyzer 3 through the main suction pump 2c. In this way, the zero-point calibration of the analyzer 3 is performed. In addition, even if the calibration gas is supplied under pressure from a gas cylinder, it is opened to the atmosphere through the three-way electromagnetic valve 6d of the overflow flow path 6, thereby allowing the sample gas to flow in the main flow path 2 ( Figure 3 ) or when the first purge gas is flowing ( Figure 4 ) at the connection point 6x is minimal.

[0044] Then, if Figure 6 As shown, the span calibration is performed by supplying the span gas from the span gas flow path 42 to the analyzer 3. Here, the electromagnetic on-off valve 2d of the main flow path 2 is closed, and the electromagnetic on-off valve 42a of any one of the span gas flow paths 42 is opened. By setting this state, the span gas is introduced from the span gas flow path 42 to the measuring cell 31 of the analyzer 3 using the main suction pump 2c. In this way, the span calibration of the analyzer 3 is performed. In addition, even if the calibration gas is supplied under pressure from a gas cylinder, it is opened to the atmosphere through the three-way electromagnetic valve 6d of the overflow flow path 6, thereby allowing the sample gas to flow in the main flow path 2 ( Figure 3 ) or when the first purge gas is flowing ( Figure 4 ) at the connection point 6x is minimal.

[0045] After the series of actions of the purge process, zero point calibration and span calibration are completed, continuous analysis is performed again. Specifically, when the series of actions are completed, the electromagnetic on-off valve 2d of the main flow path 2 is opened to restart the introduction of the sample gas to the analyzer 3, and the bypass path 9 is blocked by the three-way electromagnetic valve 6d of the overflow flow path 6 to restart the exhaust of the sample gas by the overflow flow path 6 (refer to Figure 3 ).

[0046] <When continuous analysis ends (before or during system shutdown)> If the continuous analysis is finished, before or when the system is stopped, Figure 7 As shown, the three-way valve 2i is switched to supply the second purge gas from the second purge gas flow path 5B. Here, the three ports of the three-way valve 2i are in the following state: the port connected to the downstream side of the main flow path 2 is closed, and the port connected to the upstream side of the main flow path 2 is connected to the port connected to the second purge gas flow path 5B. In addition, in the <normal analysis> and <calibration (including purge)> described above, the three ports of the three-way valve 2i are in the following state: the port connected to the second purge gas flow path 5B is closed, and the port connected to the upstream side of the main flow path 2 is connected to the port connected to the downstream side of the main flow path 2.

[0047] In this way, the second purge gas is made to flow back to the main flow path 2 through the three-way valve 2i. Thus, the exhaust gas retained in the main flow path 2 is purged and discharged to the outside from the sampling unit 7 (second purge process). In this state, the gas continuous analysis system is stopped. In addition, in the second purge process of supplying the second purge gas from the second purge gas flow path 5B to the upstream side of the main flow path, the first purge gas can also be supplied to the downstream side of the main flow path 2 in the same manner as the above-mentioned <Calibration (including purge)> to purge the analyzer 3 and the like.

[0048] <Effects of the present embodiment> According to the gas continuous analysis system 100 of the present embodiment configured in this way, the flow path for the sample gas of the analyzer 3 is purged using the first purge gas containing water before calibrating the analyzer 3, so that the time until the indicated value of the analyzer 3 during calibration is stabilized can be shortened. Here, since the first purge gas containing water is used, the adsorbent component adsorbed on the inner surface of the measuring cell 31 of the analyzer 3 is easily detached by water molecules. As a result, the time for calibration performed between continuous analysis can be shortened, and the interruption time in the continuous analysis of the sample gas can be shortened.

[0049] <Other embodiments> For example, in the gas analysis system 100 of the embodiment, during normal continuous analysis, the sample gas is sucked by the auxiliary suction pump 6a and overflows the overflow flow path 6, and during calibration, the calibration gas is pressurized and supplied from the calibration gas cylinder in a state of being opened to the atmosphere through the bypass flow path 9. That is, in the embodiment, the pressure at the connection point 6x of the overflow flow path 6 is different during continuous analysis and calibration, and due to this influence, the internal pressure of the measuring cell 31 is different, and the indicated value of the analyzer changes.

[0050] Therefore, if Figure 8 As shown, it is ideal that the bypass flow path 9 is removed and suction is performed through the overflow flow path 6 by the auxiliary suction pump 6a during normal continuous analysis and calibration. Here, a compensation gas introduction passage 12 for introducing compensation gas such as the atmosphere is connected to the overflow flow path 6. A check valve 12a and an electromagnetic opening and closing valve 12b are provided in the compensation gas introduction passage 12. In addition, Figure 8 *1 in the figure indicates that the make-up gas introduction passage 12 branches off from the first purge gas passage 5A, and the atmosphere having passed through the dust filter 51 is introduced into the make-up gas introduction passage 12. Alternatively, the make-up gas introduction passage 12 may be provided independently of the first purge gas passage 5A.

[0051] Furthermore, when the calibration gas is pressurized from the calibration gas cylinder and supplied to the measuring cell 31 (during calibration), the electromagnetic on-off valve 12b is opened to supply the compensation gas from the compensation gas flow path 12 to the overflow flow path 6. Thus, during calibration, the compensation gas can be used to make up for the shortage of the calibration gas flow rate relative to the suction flow rate of the auxiliary suction pump 6a. Therefore, the pressure difference at the connection point 6x can be reduced during continuous analysis and calibration.

[0052] In addition, a gas at a predetermined flow rate of, for example, 1.5 L / min needs to flow in the main flow path 2. If the calibration gas at a flow rate exceeding the predetermined flow rate is not supplied from the calibration gas cylinder during calibration, the make-up gas flows back to the main flow path 2 through the make-up gas flow path 12. Therefore, it is desirable to provide flow rate sensors 41d and 42d of the calibration gas in each calibration gas flow path 4 (41, 42). With the above structure, the calibration gas supplied to the main flow path 2 can be accurately measured, and the make-up gas can be prevented from flowing back to the main flow path 2 through the make-up gas flow path 12.

[0053] Furthermore, the load of the main suction pump 2c changes during normal continuous measurement and calibration. Therefore, when calibration is performed from continuous measurement and continuous measurement is performed again, the internal pressure of the measuring cell during continuous measurement before calibration and the internal pressure of the measuring cell during continuous measurement after calibration change, resulting in a problem of poor reproducibility.

[0054] Therefore, if Figure 8 As shown, in order to reduce the load variation of the main suction pump 2c during continuous measurement and calibration, a pressure regulating flow path 13 is connected between the measuring cell 31 in the main flow path 2 and the main suction pump 2c. Here, the pressure regulating flow path 13 suppresses the load variation of the main suction pump 2c by introducing the atmosphere and the like into the main flow path 2. A dust collecting filter 13a and a pressure regulating valve 13b are provided in the pressure regulating flow path 13. Thus, the load variation of the main suction pump 2c can be reduced during continuous measurement and calibration. In addition, in order to measure the flow rate of the gas flowing in the measuring cell 31, a flow sensor 2i is provided between the connection point of the pressure regulating flow path 13 in the main flow path 2 and the measuring cell 31.

[0055] In the above-described embodiment, the zero point calibration and the span calibration are performed after the first purge process, but the first purge process and the zero point calibration may be performed simultaneously. In this case, the gas continuous analysis system 100 supplies the first purge gas from the first purge gas flow path 5A to the analyzer 3 in the middle of the continuous analysis to purge the analyzer 3, and performs the zero point calibration on the analyzer 3, and then supplies the span gas from the calibration gas flow path 4 to the analyzer 3 to perform the span calibration on the analyzer 3.

[0056] Furthermore, in the above-described embodiment, the overflow flow path 6 is provided, but the overflow flow path 6 may be omitted.

[0057] Furthermore, in the above-described embodiment, the configuration is provided with the second purge gas flow path 5B, but the configuration may be provided without the second purge gas flow path 5B.

[0058] The standard gas flow path 4 of the above embodiment supplies calibration gas as a standard gas for calibrating the analyzer 3, but may also supply verification gas as a standard gas for verifying the analyzer 3. The verification gas is a gas used to confirm the performance of the analyzer 3. By supplying the verification gas to the analyzer 3, the performance of the analyzer 3 can be confirmed.

[0059] Furthermore, the analyzer 3 of the embodiment uses an IRLAM detector, but may also be a detector using an infrared absorption method such as a detector using a non-dispersive infrared absorption method (NDIR) or a detector using a Fourier transform infrared spectroscopy method (FTIR).

[0060] In addition, if Fig. 9 As shown, the gas continuous analysis system of the present invention includes: a sampling section 7 for sampling the gas containing adsorptive components flowing in the pipeline; a main flow path 2 for the sample gas sampled by the sampling section 7 to flow; a chromatograph or a mass analyzer 11 for analyzing the adsorptive components in the sample gas flowing in the main flow path 2; and an overflow flow path 6 for discharging a part of the sample gas flowing in the main flow path 2 on the upstream side of the chromatograph or the mass analyzer 11. Examples of the chromatograph include an ion chromatograph, a gas chromatograph, and the like. In addition, in Figure 8 In the embodiment, the structures marked with the same reference numerals as those in the above embodiment are the same as those in the above embodiment. With the above structure, the sample gas introduced into the main flow path 2 can be increased in flow rate through the overflow flow path 6. As a result, the adsorptive components can be less likely to be adsorbed on the inner surface of the pipe constituting the main flow path 2, and the analysis accuracy of the trace adsorptive components analyzed by the chromatograph or mass analyzer 11 can be improved.

[0061] In addition, various modifications or combinations of the embodiments may be made within the scope not departing from the spirit of the present invention. Industrial Applicability

[0062] According to the present invention, the time required for calibration or verification of an analyzer for analyzing a sample gas containing adsorptive components can be shortened. Description of Reference Numerals

[0063] 100 Infrared Gas Analyzer 2 Main flow 3 Analyzer 4Calibration gas flow path (standard gas flow path) 41 Zero gas flow path 42 Range Gas Flow 5A purge gas flow path (first purge gas flow path) 5B Second purge gas flow path 6 Overflow flow path 2b Throttle 2c Main suction pump 6a Auxiliary suction pump.

Claims

1. A gas continuous analysis system, characterized in that: include: a main flow path for the flow of sample gas containing adsorptive components; an analyzer for analyzing adsorptive components in the sample gas flowing in the main flow path; A standard gas flow path for supplying standard gas for calibration or verification to the analyzer; as well as a purge gas flow path for supplying a purge gas containing water to a flow path of the analyzer through which the sample gas passes; The sample gas is introduced into the main flow path and the sample gas is continuously analyzed by the analyzer. In the middle of the continuous analysis, the purge gas is supplied from the purge gas flow path to the analyzer to purge the flow path of the analyzer through which the sample gas passes. Then, the standard gas is supplied from the standard gas flow path to the analyzer to calibrate or verify the analyzer.

2. The gas continuous analysis system according to claim 1, characterized in that: The purge gas flow path supplies atmospheric air to a flow path of the analyzer through which the sample gas passes.

3. The gas continuous analysis system according to claim 1 or 2, characterized in that: The analyzer analyzes HF, HCl or NH 3 as the adsorptive component.

4. The gas continuous analysis system according to any one of claims 1 to 3, characterized in that: The standard gas flow path has: a zero-point gas flow path for supplying a zero-point gas to the analyzer; and A span gas flow path supplies the span gas to the analyzer, In the exhaust continuous analysis system, in the middle of the continuous analysis, the purge gas is supplied from the purge gas flow path to the analyzer to purge the flow path of the analyzer through which the sample gas passes. Next, the zero point gas is supplied from the zero point gas flow path to the analyzer to perform zero point calibration on the analyzer, and the range gas is supplied from the range gas flow path to the analyzer to perform range calibration on the analyzer.

5. The gas continuous analysis system according to any one of claims 1 to 3, characterized in that: The standard gas flow path supplies the range gas to the analyzer. In the exhaust gas continuous analysis system, in the middle of the continuous analysis, the purge gas is supplied from the purge gas flow path to the analyzer to purge the flow path of the analyzer through which the sample gas passes, and the analyzer is zero-calibrated. Then, the range gas is supplied from the standard gas flow path to the analyzer to perform a range calibration on the analyzer.

6. The gas continuous analysis system according to any one of claims 1 to 5, characterized in that: The apparatus further comprises a second purge flow path connected to the upstream side of the analyzer in the main flow path, and a second purge gas is supplied from the connection point toward the upstream side of the main flow path. In the exhaust gas continuous analysis system, after the continuous analysis is completed, the second purge gas is supplied from the second purge flow path to purge the upstream side of the connection point of the second purge flow path.

7. The gas continuous analysis system according to any one of claims 1 to 6, characterized in that: An overflow flow path is further included, the overflow flow path discharging a portion of the sample gas flowing in the main flow path on the upstream side of the analyzer.

8. The gas continuous analysis system according to claim 7, characterized in that: A throttling portion is provided between the connection point of the overflow flow path in the main flow path and the analyzer, and a main suction pump is provided on the downstream side of the analyzer in the main flow path. The overflow flow path is provided with a sub-suction pump.

9. A gas continuous analysis system, characterized in that: include: A sampling section for sampling the gas containing the adsorptive component flowing in the pipeline; A main flow path for the sample gas sampled by the sampling part to flow; a chromatograph or a mass analyzer for analyzing adsorptive components in the sample gas flowing in the main flow path; as well as The overflow flow path discharges a portion of the sample gas flowing in the main flow path on the upstream side of the analyzer.

10. A gas continuous analysis method, which is a gas continuous analysis method using a measurement system, the measurement system comprising: a main flow path for the flow of sample gas containing adsorptive components; an analyzer for analyzing adsorptive components in the sample gas flowing in the main flow path; A standard gas flow path supplies a standard gas for calibration or verification to the analyzer; and a purge gas flow path supplies a purge gas containing water to a flow path of the analyzer through which the sample gas passes. The gas continuous analysis method is characterized in that: The sample gas is introduced into the main flow path and the sample gas is continuously analyzed by the analyzer. In the middle of the continuous analysis, the purge gas is supplied from the purge gas flow path to the analyzer to purge the flow path of the analyzer through which the sample gas passes. Then, the standard gas is supplied from the standard gas flow path to the analyzer to calibrate or verify the analyzer.

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