Gas intake device and method for gas analysis

Abstract

The present invention relates to an air intake device and method for gas analysis, and belongs to the field of chemical technology. It includes a gas source container to be analyzed, a bus pipeline, an air intake pipeline, an analytical instrument, an air intake pipe purge branch, a vacuum branch, an analytical instrument purge branch and a vacuum pump. Each bus pipeline connected to the gas source container to be analyzed is provided with a gas source valve, a pressure reducing valve, a one-way valve and a branch valve in sequence. An air intake valve is provided at one end of the air intake pipeline close to the analytical instrument; multiple gas source containers to be analyzed are connected to one end of the air intake pipeline through a bus pipeline, and the other end of the air intake pipeline is connected to the analytical instrument. One end of the air intake pipe purge branch is connected to the air intake pipeline close to one side of the bus, and the other end is connected to the pipeline purge gas; one end of the analytical instrument purge branch is connected to the analytical instrument, and the other end is connected to the instrument purge gas. The replacement efficiency of the residual gas to be analyzed is improved, and the usage of the gas source to be analyzed is reduced.

Description

Technical Field

[0001] The invention relates to an air intake device and a method for gas analysis, belonging to the technical field of chemical industry. Background Art

[0002] Process testing and product testing are important means of quality control. For semiconductor production processes, substandard gas purity or component content may cause device performance degradation, shortened life, and even cause the entire chip to be scrapped.

[0003] Usually, the gas source to be tested is installed on the sampling pipeline outside the analytical instrument, and the sampling pipeline is directly purged. However, the impurity gas remaining on the wall of the sampling pipeline and in the dead corner is very stubborn. Only by purging the sampling pipeline inside and outside the instrument for a long time can the impurity gas be completely discharged and the pipeline be kept clean. This purging method not only takes a long time and has a slow detection speed, but also consumes a large amount of the gas source to be tested, greatly increasing the analysis cost. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a gas intake device and method for gas analysis.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A gas intake device for gas analysis, the device comprises a gas source container to be analyzed, a bus pipe, an intake pipe, an analytical instrument, an intake pipe purge branch, a vacuum branch, an analytical instrument purge branch and a vacuum pump, a plurality of gas source containers to be analyzed are connected to one end of the intake pipe through the bus pipe, and the other end of the intake pipe is connected to the analytical instrument, a gas source valve, a pressure reducing valve, a one-way valve and a branch valve are sequentially arranged on the bus pipe connected to each gas source container to be analyzed, the pressure reducing valve is used to reduce the pressure of the gas source to be analyzed to the intake pressure of the analytical instrument; bypasses are arranged on both sides of the pressure reducing valve, and bypass valves are arranged on the bypass; one end of the intake pipe close to the analytical instrument An intake valve is provided; one end of the intake pipe purge branch is connected to the intake pipeline close to the bus side, and the other end is connected to the pipeline purge gas; the pipeline purge gas is used to purge the intake pipeline; one end of the vacuum branch is connected to the intake pipeline close to the intake valve side, and the other end is connected to a vacuum pump; one end of the analytical instrument purge branch is connected to the analytical instrument, and the other end is connected to the instrument purge gas; the instrument purge gas is used to purge the analytical instrument; the intake purge branch, the vacuum branch, and the analytical instrument purge branch are respectively provided with a first valve, a second valve, and a second valve, and a pressure sensor is provided on the intake pipeline for detecting the pressure in the intake pipeline.

[0007] Furthermore, the device also includes a controller, which is used to receive the pressure signal of the pressure sensor and control the opening and closing of each valve.

[0008] Furthermore, the air intake pipeline can be connected to multiple analytical instruments through multiple branches, and each branch is provided with a valve, which can be used for different analytical tests of the gas source to be analyzed.

[0009] Furthermore, the purity of the pipeline purge gas and the instrument purge gas is higher than the purity of the gas source to be analyzed.

[0010] Furthermore, the pipeline purge gas and instrument purge gas adopt a gas source that is lower in cost than the gas source to be analyzed and does not affect the analysis results.

[0011] Furthermore, the one-way valve, the air intake valve, the branch valve, the first valve, the second valve and the third valve are all high-pressure valves.

[0012] Furthermore, the air source valve, bypass valve, air intake valve, branch valve, first valve, second valve and third valve are all pneumatic valves.

[0013] A gas analysis method based on the device, the method steps comprising:

[0014] (1) The air inlet valve is closed, and the third valve is opened. The instrument purge gas enters the air inlet pipeline along the purge branch of the analytical instrument to continuously purge the analytical instrument; air is prevented from entering the instrument from the instrument tail pipe or pipeline joints;

[0015] (2) Close the branch valve and the first valve, open the second valve, use a vacuum pump to evacuate the pipeline to 5-10 Pa, maintain for 2-5 minutes, close the second valve, open the first valve, and allow the pipeline purge gas to enter the intake pipeline along the intake pipe purge branch to purge the pipeline to a pressure of 0.1-0.2 MPa; perform vacuuming and purging alternately for several times to completely replace the residual gas in the intake pipeline;

[0016] (3) Open the gas source valve on the busbar pipeline where the gas source to be analyzed is located, close it after the gas source to be analyzed passes through, close the bypass valve, open the second valve and the branch valve, vacuum the low-pressure end of the pressure reducing valve to 2-5 Pa, maintain it for 0.5-2 minutes, open the bypass valve, vacuum the high-pressure end of the pressure reducing valve to 2-5 Pa, maintain it for 0.5-2 minutes, and close the second valve;

[0017] (4) Close the bypass valve on the busbar pipeline where the gas source to be analyzed is located, and open the gas source valve and branch valve on the busbar pipeline where the gas source to be analyzed is located in sequence. After closing the third valve, immediately open the air inlet valve to introduce the gas source to be analyzed into the analytical instrument for analysis.

[0018] Furthermore, the opening and closing of each valve is controlled by a controller.

[0019] Furthermore, the controller receives the pressure signal from the pressure sensor and controls the opening and closing of each valve.

[0020] Beneficial Effects

[0021] The present invention introduces an intake pipe purge gas branch and a vacuum branch into the analysis bus, and alternately vacuums and purges the pipeline between the branch valve on the bus and the intake valve to replace the residual gas in the intake pipeline, thereby improving the replacement efficiency of the analysis residual gas and reducing the amount of gas source to be analyzed. The invention is particularly suitable for the analysis of higher-value gases.

[0022] The present invention adds bypasses before and after the pressure reducing valve and arranges a bypass valve, and vacuumizes the high-pressure and low-pressure end pipelines of the pressure reducing valve in turn, thereby improving the vacuuming efficiency, reducing the amount of analytical gas source, and accelerating the detection speed.

[0023] The present invention adopts instrument purge gas to continuously purge the analytical instrument, so that the analytical instrument is in a state of waiting for analysis at any time, thereby improving the analysis efficiency.

[0024] The present invention adopts a controller to control the valve, which can realize automatic processing and reduce human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the device of the present invention;

[0026] Among them, 1-gas source container to be analyzed, 2-gas source valve, 3-pressure reducing valve, 4-bypass valve, 5-check valve, 6-branch valve, 7-first valve, 8-pressure sensor, 9-second valve, 10-vacuum pump, 11-inlet valve, 12-third valve, 13-analytical instrument. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with specific embodiments.

[0028] Example 1

[0029] like Figure 1As shown, an air intake device for gas analysis, the device includes a gas source container 1 to be analyzed, a bus, an air intake pipeline, an analytical instrument 13, an air intake purge branch, a vacuum branch, an analytical instrument purge branch and a vacuum pump 10, a plurality of gas source containers 1 to be analyzed are connected to one end of the air intake pipeline through the pipeline of the bus, and the other end of the air intake pipeline is connected to the analytical instrument 13, and a gas source valve 2, a pressure reducing valve 3, a one-way valve 5 and a branch valve 6 are sequentially arranged on the bus pipeline connected to each gas source container to be analyzed, the pressure reducing valve 3 is used to reduce the pressure of the gas source to be analyzed to the intake pressure of the analytical instrument 13; bypasses are arranged on both sides of the pressure reducing valve 3, and bypass valves 4 are arranged on the bypass; an air intake valve 11 is arranged on the end of the air intake pipeline close to the analytical instrument 13 ; One end of the intake pipe purge branch is connected to the intake pipeline close to the bus side, and the other end is connected to the pipeline purge gas; the pipeline purge gas is used to purge the intake pipeline; one end of the vacuum branch is connected to the intake pipeline close to the intake valve 11 side, and the other end is connected to the vacuum pump 10; the vacuum pump 10 is used to vacuum the pipeline; one end of the analytical instrument purge branch is connected to the analytical instrument 13, and the other end is connected to the instrument purge gas; the instrument purge gas is used to purge the analytical instrument 13; the intake purge branch, the vacuum branch, and the analytical instrument purge branch are respectively provided with a first valve 7, a second valve 9, and a second valve 12, and a pressure sensor 8 is provided on the intake pipeline for detecting the pressure in the intake pipeline.

[0030] The device also includes a controller, which is used to receive the pressure signal of the pressure sensor and control the opening and closing of each valve.

[0031] The air inlet pipeline can be connected to multiple analytical instruments through multiple branches, and each branch is provided with a valve, which can be used for different analytical tests on the gas source to be analyzed.

[0032] The purity of the pipeline purge gas and the instrument purge gas is higher than the purity of the gas source to be analyzed.

[0033] The pipeline purge gas and instrument purge gas adopt a gas source which has a lower cost than the gas source to be analyzed and does not affect the analysis result.

[0034] The one-way valve 5, the air intake valve 11, the branch valve 6, the first valve 7, the second valve 9 and the third valve 12 are all high-pressure valves.

[0035] The gas source valve 2, the bypass valve 4, the air inlet valve 11, the branch valve 6, the first valve 7, the second valve 9 and the third valve 12 are all pneumatic valves.

[0036] A gas analysis method based on the device, the method steps comprising:

[0037] (1) The air inlet valve 11 is closed, and the third valve 12 is opened. The instrument purge gas enters the air inlet pipeline along the purge branch of the analytical instrument to continuously purge the analytical instrument 13;

[0038] (2) Close the branch valve 6 and the first valve 7, open the second valve 9, use the vacuum pump 10 to evacuate the intake pipeline to 5-10 Pa, maintain for 2-5 minutes, close the second valve 9, open the first valve 7, and the pipeline purge gas enters the intake pipeline along the intake pipe purge branch to purge the pipeline between the branch valve 6 and the intake valve 11 to a pressure of 0.1-0.2 MPa; vacuuming and purging are performed alternately for several times to replace the residual gas in the intake pipeline;

[0039] (3) Open the gas source valve 2 on the busbar pipeline where the gas source to be analyzed is located, close it after the gas source to be analyzed passes through, close the bypass valve 4, open the second valve 9 and the branch valve 6, evacuate the low-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain it for 0.5-2 minutes, open the bypass valve 4, evacuate the high-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain it for 0.5-2 minutes, and close the second valve 9;

[0040] (4) Close the bypass valve 4 on the bus pipe where the gas source to be analyzed is located, open the gas source valve 2 and the branch valve 6 on the bus pipe where the gas source to be analyzed is located in sequence, and immediately open the air inlet valve 11 after closing the third valve 12 to introduce the gas source to be analyzed into the analytical instrument for analysis.

[0041] The opening and closing of each valve is controlled by a controller.

[0042] The controller receives the pressure signal from the pressure sensor 8 and controls the opening and closing of each valve.

[0043] Example 2

[0044] The H2O in the neon gas in the container to be analyzed is analyzed using an optical cavity oscillation water analyzer.

[0045] Nitrogen with a purity of 99.9999% is used as instrument purge gas and pipeline purge gas. The inlet pressure requirement of the water analyzer is 0.17MPa, and the pressure reducing valve 3 is used to reduce the gas source to be analyzed from 15MPa to 0.17MPa. In order to reduce the damage to the valve and pipe fittings when the pressure reducing valve 3 is out of control, the design pressure of the one-way valve 5, the branch valve 6, the first valve 7, the second valve 9, the inlet valve 11, and the third valve 12 is 20MPa, and the upper limit of the range of the vacuum pressure gauge is 20MPa. The previous analysis was used to analyze H2O in helium. In the last analysis, the H2O in helium was 0.48ppm.

[0046] The specific steps of the analysis are as follows:

[0047] (1) Purging the analytical instrument: The air inlet valve 11 is closed, the third valve 12 is kept open, and 99.9999% nitrogen is continuously purged through the internal pipeline of the water analyzer, and the reading of the water analyzer is kept less than 10 ppb.

[0048] (2) Vacuuming and purging the intake air: Since the H2O in the helium gas analyzed last time was 0.48ppm, and the H2O in the neon gas is required to be less than 0.20ppm, the analysis bus needs to be fully replaced. Close the branch valve 6, the intake valve 11 and the first valve 7, open the second valve 9 and use the vacuum pump 10 to evacuate to 5Pa, and maintain for 2 minutes; close the second valve 9, open the first valve 7, fill in 99.9999% nitrogen to a pressure of 0.2MPa, and close the first valve 7; repeat the above vacuuming and replacement 3 times, and finally evacuate the pipeline to 5Pa.

[0049] (3) Evacuate the busbar pipeline where the gas source to be analyzed is located: open the gas source valve 2 and close it after the gas source to be analyzed passes through. Close the bypass valve 4, open the second valve 9 and the branch valve 6, and evacuate the low-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain for 2 minutes, then open the bypass valve 4 to evacuate the high-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain for 0.5 minutes, and finally close the second valve 9.

[0050] (4) Gas sample analysis: Close the bypass valve 4, open the gas source valve 2 and the branch valve 6 in sequence, close the third valve 12, and immediately open the air inlet valve 11 to introduce the neon gas to be analyzed into the analysis instrument 13 for analysis. The analysis result is 0.12 ppm.

[0051] Nitrogen gas with a purity of 99.9999% was introduced to evacuate the analytical bus and evacuate the high and low ends of the pressure reducing valve in turn, which improved the replacement efficiency and reduced the use of the more expensive neon gas.

[0052] Example 3

[0053] Helium ion chromatography is used to analyze the impurity content of Xe in the container to be analyzed. The impurities to be analyzed are H2, O2+Ar, N2, CH4, CO and CO2. The inlet pressure of helium ion chromatography is required to be <0.5MPa. The pressure reducing valve 3 is used to reduce the gas source to be analyzed from 10MPa to 0.3MPa.

[0054] Since helium ionization chromatography does not respond to helium, helium with a purity of 99.9999% is used as instrument purge gas and pipeline purge gas. Xenon gas is expensive, costing 100,000 yuan per cubic meter. The helium ionization chromatography results of pipeline purge gas helium are used to judge the replacement effect of the analysis bus, thereby reducing the amount of xenon gas used for analysis.

[0055] The specific steps of the analysis are as follows:

[0056] (1) Purging the analytical instrument: the inlet valve 11 is closed, the third valve 12 is continuously opened, 99.9999% helium is continuously supplied to the helium ion chromatography column, and the electrical signal is maintained at 1×10 5 the following.

[0057] (2) Vacuum the intake pipeline: close the branch valve 6, the intake valve 11 and the first valve 7, open the second valve 9 to evacuate the bus to -0.1MPa, and maintain for 2 minutes; close the second valve 9, open the first valve 7, fill with 99.9999% helium to a pressure of 0.2MPa, and close the first valve 7; repeat the above vacuum replacement 3 times, and finally evacuate the pipeline to -0.1MPa. Open the pipeline purge gas valve 7, close the third valve 12, and then open the intake valve 11, analyze the pipeline purge gas until the H2, O2+Ar, N2, CH4, CO and CO2 in the helium meet the impurity content requirements of Xe, and stop vacuum replacement of the analysis bus.

[0058] (3) Evacuate the busbar pipeline where the gas source to be analyzed is located: open the gas source valve 2 and close it after the gas source to be analyzed passes through. Close the bypass valve 4, open the second valve 9 and the branch valve 6, and evacuate the low-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain for 1 minute, then open the bypass valve 4 to evacuate the high-pressure end of the pressure reducing valve 3 to 2-5 Pa, maintain for 0.5 minutes, and finally close the second valve 9.

[0059] (4) Gas sample analysis: close the bypass valve 4, open the gas source valve 2 and the branch valve 6 in sequence, close the third valve 12, and immediately open the air inlet valve 11 to introduce the neon gas to be analyzed into the analysis instrument 13 for analysis.

[0060] The xenon gas index and the helium ionization chromatography analysis results of helium and xenon are shown in Table 1.

[0061] Table 1 Helium ionization chromatography analysis results

[0062]

[0063] Example 4

[0064] Based on the device described in Example 1, this embodiment is further provided with a controller, each valve is pneumatically controlled, and a vacuum pressure gauge is remotely transmitted for automatic control. Only one gas source to be analyzed is analyzed each time, and the branch valve 6 and the first valve 7 are interlocked and cannot be opened at the same time. The air inlet valve 11 and the third valve 12 are interlocked and cannot be opened at the same time.

[0065] The intake pipeline is automatically controlled to be vacuumed, purged and replaced: the controller controls the branch valve 6, the intake valve 11 and the first valve 7 to be closed, controls the second valve 9 to be opened, and the vacuum pump 10 to evacuate. When the pressure sensor detects that the pressure in the pipeline reaches 5-10Pa, the controller receives the pressure signal of the pressure sensor and controls the state of the above valves to be maintained for 2-5min; then, the controller controls the second valve 9 to be closed and the first valve 7 to be opened. When the pipeline purge gas is filled and purged to a pressure of 0.1-0.2MPa, the pressure sensor transmits the pressure signal to the controller, and the controller controls the first valve 7 to be closed;

[0066] The vacuuming of the bus pipeline where the gas source to be analyzed is located is automatically controlled: the controller controls the gas source valve 2 to open, and closes it after the gas source to be analyzed passes through; and controls the bypass valve 4 to close, the second valve 9 and the branch valve 6 to open, and the vacuum pump 10 to vacuum the low-pressure end of the pressure reducing valve 3. When the pressure sensor detects that the pressure in the pipeline reaches 2-5Pa, the controller receives the pressure signal of the pressure sensor and controls the state of the above valve to be maintained for 0.5-2min. Subsequently, the bypass valve 4 is controlled to open, and the high-pressure end of the pressure reducing valve 3 is vacuumed. When the pressure sensor detects that the pressure in the pipeline reaches 2-5Pa, the controller receives the pressure signal of the pressure sensor and controls the state of the above valve to be maintained for 0.5-2min. Finally, the second valve 9 is controlled to be closed.

[0067] In summary, the invention includes but is not limited to the above embodiments. Any equivalent substitution or partial improvement made under the spirit and principle of the invention shall be deemed to be within the protection scope of the invention.

Claims

1. A gas analysis method based on an air intake device, characterized in that: The device comprises a gas source container (1) to be analyzed, a bus, an air intake pipeline, an analytical instrument (13), an air intake purge branch, a vacuum branch, an analytical instrument purge branch and a vacuum pump (10). A plurality of gas source containers (1) to be analyzed are connected to one end of the air intake pipeline via a bus pipeline, and the other end of the air intake pipeline is connected to the analytical instrument (13). The bus pipeline connected to each gas source container to be analyzed is provided with a gas source valve (2), a pressure reducing valve (3), a non-return valve (5) and a branch valve (6) in sequence. The pressure reducing valve (3) is used to reduce the pressure of the gas source to be analyzed to the intake pressure of the analytical instrument (13); bypasses are provided on both sides of the pressure reducing valve (3), and bypass valves (4) are provided on the bypass; the air intake pipeline An air intake valve (11) is provided at one end of the upper portion close to the analytical instrument (13); one end of the air intake purge branch is connected to the air intake pipeline close to the bus, and the other end is connected to the pipeline purge gas; one end of the vacuum branch is connected to the air intake pipeline between the bus close to the air intake valve (11) and the air intake valve (11), and the other end is connected to a vacuum pump (10); one end of the analytical instrument purge branch is connected to the analytical instrument (13), and the other end is connected to the instrument purge gas; the air intake purge branch, the vacuum branch, and the analytical instrument purge branch are respectively provided with a first valve (7), a second valve (9), and a third valve (12); a pressure sensor (8) is provided on the air intake pipeline for detecting the pressure in the air intake pipeline; The steps of the gas analysis method include: (1) the air inlet valve (11) is closed, the third valve (12) is opened, and the instrument purge gas enters the air inlet pipeline along the analytical instrument purge branch to continuously purge the analytical instrument (13); (2) Close the branch valve (6) and the first valve (7), open the second valve (9), use the vacuum pump (10) to evacuate the intake pipeline to 5-10 Pa, maintain for 2-5 minutes, close the second valve (9), open the first valve (7), and allow the pipeline purge gas to enter the intake pipeline along the intake purge branch to purge the pipeline between the branch valve (6) and the intake valve (11) to a pressure of 0.1-0.2 MPa; perform vacuuming and purging alternately for several times to completely replace the residual gas in the intake pipeline; (3) Open the gas source valve (2) on the busbar pipeline where the gas source to be analyzed is located, close it after the gas source to be analyzed passes through, close the bypass valve (4), open the second valve (9) and the branch valve (6), evacuate the low-pressure end of the pressure reducing valve (3) to 2-5 Pa, maintain it for 0.5-2 minutes, open the bypass valve (4), evacuate the high-pressure end of the pressure reducing valve (3) to 2-5 Pa, maintain it for 0.5-2 minutes, and close the second valve (9); (4) Close the bypass valve (4) on the busbar pipeline where the gas source to be analyzed is located, open the gas source valve (2) and the branch valve (6) on the busbar pipeline where the gas source to be analyzed is located in sequence, and immediately open the gas inlet valve (11) after closing the third valve (12) to introduce the gas source to be analyzed into the analytical instrument for analysis.

2. A gas analysis method according to claim 1, characterized in that: The device also includes a controller, which is used to receive the pressure signal of the pressure sensor and control the opening and closing of each valve.

3. A gas analysis method according to claim 1, characterized in that: The air intake pipeline is connected to a plurality of analytical instruments via a plurality of branches, and valves are arranged on the branches.

4. A gas analysis method according to claim 1, characterized in that: The purity of the pipeline purge gas and the instrument purge gas is higher than the purity of the gas source to be analyzed.

5. A gas analysis method according to claim 1, characterized in that: The pipeline purge gas and instrument purge gas adopt a gas source which has a lower cost than the gas source to be analyzed and does not affect the analysis result.

6. A gas analysis method according to claim 1, characterized in that: The one-way valve (5), the air intake valve (11), the branch valve (6), the first valve (7), the second valve (9) and the third valve (12) are all high-pressure valves.

7. A gas analysis method according to claim 1, characterized in that: The air source valve (2), the bypass valve (4), the air intake valve (11), the branch valve (6), the first valve (7), the second valve (9) and the third valve (12) are all pneumatic valves.

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