A steel cylinder processing system and its use method and application

Abstract

The present invention discloses a steel cylinder processing system and a use method and application thereof, which comprises four units, namely, a steel cylinder unit: one or more steel cylinders wrapped with a heating blanket, a diaphragm valve, a vacuum gauge and a pressure sensor; second, an analysis unit: comprising a diaphragm valve and an analysis device; third, a test gas unit: comprising a diaphragm valve, a one-way valve, a filter and a purification device; fourth, an evacuation unit: comprising a diaphragm valve and a vacuum device; a main pipe coming out of the steel cylinder is connected with a diaphragm valve V1, a vacuum gauge, a pressure sensor, an analysis unit, a test gas unit and an evacuation unit in sequence; the vacuum gauge is connected to the main pipe through a diaphragm valve V2, and the pressure sensor is connected to the main pipe through a diaphragm valve V3; the analysis device is connected to the main pipe through a diaphragm valve V4, and is connected to the test gas unit through a diaphragm valve V7; the purification device is connected to the main pipe through a filter F1, a one-way valve C1 and a diaphragm valve V5 in sequence; and the vacuum device is connected to the main pipe through a diaphragm valve V6.

Description

Technical Field

[0001] The invention relates to a steel cylinder processing system and a use method thereof, and in particular to the processing of steel cylinders for high-purity electronic special gases. Background Art

[0002] Electronic gases are indispensable raw materials for the production of ultra-large-scale integrated circuits (LSI), flat panel display devices, compound semiconductor devices, solar cells, optical fibers, and other electronic industries. They are widely used in thin film, etching, doping, vapor deposition, diffusion and other processes. With the rapid development of the industry, the electronic industry has higher and higher requirements for the purity of electronic gases, and the requirements for impurities such as moisture, oxygen, and nitrogen are becoming more and more stringent. Generally, the purity of ultra-high purity gases is above 99.9999%, and the indicators of impurity moisture, oxygen, and nitrogen are usually required to be less than 1ppmv, and the moisture indicators of some gases are even less than 50ppbv. As an electronic gas manufacturer, the treatment of steel cylinders for filling gas in packaging containers is an important part of the gas purification process. It is particularly important to prevent secondary contamination of steel cylinders.

[0003] Currently, the most common method for treating steel cylinders is to heat the cylinders, fill them with inert gas, evacuate them, and repeatedly fill and evacuate them to treat the impurities in the cylinders. However, the treatment system used has low cleanliness and poor air tightness. The moisture, oxygen and nitrogen impurity gas content in the treated cylinders is still relatively high, which cannot meet the use requirements of the electronics industry.

[0004] Patent application 201710060733.8 discloses a steel cylinder processing system, which places the steel cylinders in an oven for heating. The system is equipped with a nitrogen pipe, an exhaust pipe, a vacuum pump and a processing pool. The purpose of this method is to safely dispose of steel cylinders filled with materials of unknown composition and eliminate potential sources of danger, but the treated steel cylinders cannot meet the use requirements of the electronics industry.

[0005] Patent ZL201720854287.3 discloses a device for reducing the moisture content in a steel cylinder, including an air displacer, a drying mechanism, a nitrogen cylinder, an exhaust pipe and a gas pipe. The device for reducing the moisture content in a steel cylinder heats the steel cylinder to convert the moisture on the inner wall of the steel cylinder into water vapor. The nitrogen is fully mixed with the water vapor in the cylinder and discharged out of the cylinder through a vacuum pump. Although the purpose of reducing the moisture content in the cylinder is achieved, the oxygen and nitrogen impurity gases in the cylinder are not removed, and the use requirements of the electronics industry cannot be met. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a steel cylinder processing system, through which trace impurities such as moisture, oxygen and nitrogen can be removed and detected to meet the use requirements of the electronics industry.

[0007] The second technical problem to be solved by the present invention is to provide a method for using the system.

[0008] To solve the first technical problem, the technical solution of the present invention is: a steel cylinder processing system, including four units, first, a steel cylinder unit: one or more steel cylinders wrapped with a heating blanket, a diaphragm valve, a vacuum gauge and a pressure sensor; second, an analysis unit: including a diaphragm valve and an analysis device; third, a test gas unit: including a diaphragm valve, a one-way valve, a filter and a purification device; fourth, an evacuation unit: including a diaphragm valve and a vacuum device; the main pipe coming out of the steel cylinder 1 is connected with a diaphragm valve V1, a vacuum gauge 3, a pressure sensor 4, an analysis unit, a test gas unit and an evacuation unit in sequence; the vacuum gauge 3 is connected to the main pipe through a diaphragm valve V2, and the pressure sensor 4 is connected to the main pipe through a diaphragm valve V3; the analysis device 5 is connected to the main pipe through a diaphragm valve V4, and is connected to the test gas unit through a diaphragm valve V7; the purification device 6 is connected to the main pipe through a filter F1, a one-way valve C1, and a diaphragm valve V5 in sequence; the vacuum device 7 is connected to the main pipe through a diaphragm valve V6. The vacuum gauge is preferably a cold cathode ionization vacuum gauge.

[0009] Furthermore, the cylinder processing system introduces a PLC control cabinet 8 to realize automatic control. The PLC control cabinet 8 includes a cylinder processing program and a temperature control module of the heating blanket 2. The heating blanket 2, the vacuum gauge 3 and the pressure sensor 4 are connected to the PLC control cabinet 8. The PLC control cabinet 8 controls the cylinder temperature and the opening and closing of the diaphragm valve. The diaphragm valve is a diaphragm valve with remote control.

[0010] The analysis device 5 is used to complete the detection of trace moisture, trace oxygen and nitrogen in the gas in the cylinder. The minimum detection limit of moisture is not more than 2ppbv, the minimum detection limit of oxygen is not more than 0.01ppmv, and the minimum detection limit of nitrogen is not more than 0.01ppmv.

[0011] The purification equipment 6 is used to purify the detection gas, which includes helium, argon and their mixed gases. The purified detection gas is used to detect the impurity content in the cylinder. The moisture, oxygen and nitrogen content in the purified detection gas should be less than 10ppbv.

[0012] The vacuum equipment 7 is composed of two-stage pumps, the front pump is a Roots pump, and the secondary pump is a turbomolecular pump. The vacuum degree can reach 10 -8 Pa.

[0013] The pipes connecting each unit and equipment are EP-grade stainless steel pipes, the filters are high-precision ultra-clean filters, the one-way valves are EP-grade, the pipes are connected with EP-grade welding joints, and the entire system is connected with metal face sealing (VCR) joints and orbital automatic welding technology (TIG).

[0014] To solve the second technical problem, the present invention provides a method for using the system, comprising the following steps:

[0015] (1) Detection gas test: The detection gas purified by the purification equipment is analyzed by the analysis equipment. The moisture, oxygen and nitrogen contents in the detection gas are all lower than 10ppbv, which is qualified.

[0016] (2) Vacuum test: Test the vacuum degree of the cylinder and wait until the reading of the cold cathode ionization vacuum gauge 3 reaches 10 -8 Pa, disconnect the vacuum equipment and keep the vacuum degree for 30 minutes without reducing it. The vacuum degree is qualified.

[0017] (3) Heating the cylinder: (3) Heating the cylinder: The cylinder is heated to a set temperature by means of a heating blanket 2. The temperature control range of the cylinder is preferably between 100 and 120°C.

[0018] (4) Evacuate: Connect the cylinder to the vacuum equipment and wait until the reading on the vacuum gauge 3 reaches 10. -8 Pa, maintain for 4h, and turn off the vacuum equipment.

[0019] (5) Cylinder test: Introduce the test gas from the purification equipment into the cylinder. When the pressure of the pressure sensor reaches 50-100 psi, stop the gas supply. Use the analysis equipment to analyze the moisture, oxygen and nitrogen content in the test cylinder. If the moisture is less than 50 ppbv, the oxygen is less than 0.10 ppmv, and the nitrogen is less than 0.10 ppmv, it is considered "qualified". Turn off the test equipment and connect the vacuum equipment. Wait until the vacuum gauge reading reaches 10 -8 When the test value of water, oxygen and nitrogen is not up to standard, return to step (4) and process again.

[0020] Furthermore, the cylinder handling system is connected to a PLC control cabinet equipped with a cylinder handling program and a heating blanket temperature control module, and can realize automatic processing, including the following steps:

[0021] (1) Gas test: Start the cylinder processing program in the PLC control cabinet 8. The system automatically opens the diaphragm valve V7 with remote control to analyze the moisture, oxygen and nitrogen content in the test gas. If the analysis values ​​are all lower than 10ppbv, it is qualified. The program automatically closes the diaphragm valve V7 with remote control and enters the vacuum test program.

[0022] (2) Vacuum test: The program automatically opens the diaphragm valve V6 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V1 with remote control in sequence to test the system vacuum degree. Wait until the reading of vacuum gauge 3 reaches 10. -8After reaching Pa, the program automatically closes the diaphragm valve V6 with remote control and maintains it for 30 minutes. If the vacuum degree does not decrease, click the "Test Pass" button to enter the cylinder heating program. If the vacuum degree decreases during the test, the program alarms, reinstalls the cylinder connector, and clicks "Return" to repeat step (2).

[0023] (3) Heating of the cylinder: Start the temperature control module of the heating blanket 2 in the PLC. After the cylinder is automatically heated to the set temperature, it enters the evacuation program.

[0024] (4) Evacuate: Click the "Evacuate" button to open the cylinder valve. The program will automatically open the diaphragm valve V6 with remote control. Wait until the reading on the vacuum gauge 3 reaches 10. -8 Pa, maintained for 4 hours, the program automatically closes the diaphragm valve V1 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V6 with remote control in turn, and enters the cylinder test program.

[0025] (5) Cylinder test: Click the "Test" button, and the program will automatically open the diaphragm valve V5 with remote control, the diaphragm valve V3 with remote control, and the diaphragm valve V1 with remote control in turn. When the pressure of pressure sensor 4 reaches 50-100 psi, the program will automatically close the diaphragm valve V5 with remote control and open the diaphragm valve V4 with remote control to test the moisture, oxygen, and nitrogen in the cylinder. When the moisture is less than 50 ppbv, the oxygen is less than 0.10 ppmv, and the nitrogen is less than 0.10 ppmv, click the "Pass" button, and the program will automatically close the diaphragm valve V3 with remote control, the diaphragm valve V4 with remote control, and automatically open the diaphragm valve V6 with remote control and the diaphragm valve V2 with remote control. When the reading of vacuum gauge 3 reaches 10 -8 Pa, the program prompts that the processing is completed, close the cylinder valve, click the "Finish" button, the program automatically closes the diaphragm valve V6 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V1 with remote control, and the program automatically turns off the power of the heating blanket and returns to the PLC main interface. If the moisture, oxygen and nitrogen test values ​​are unqualified, the program alarms, click the "Unqualified" button, and the program automatically returns to step (4) for reprocessing.

[0026] Compared with the prior art, the steel cylinder treatment system and its use method of the present invention can realize the integrated removal and detection of impurities such as moisture, oxygen, and nitrogen in the steel cylinder, automatically treat and measure the treatment effect of the steel cylinder, avoid pollution incidents caused by unqualified steel cylinder treatment, and the treatment process is simple and efficient, meeting the use requirements of electronic industrial gases. The method can be directly applied to the treatment of steel cylinders of electronic gases such as high-purity sulfur hexafluoride, electronic-grade carbon tetrafluoride, electronic-grade nitrogen trifluoride, and electronic-grade tungsten hexafluoride. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a cylinder handling system of the present invention.

[0028] In the figure: 1 is a steel cylinder, 2 is a heating blanket, 3 is a vacuum gauge, 4 is a pressure sensor, 5 is an analysis device, 6 is a purification device, 7 is a vacuum device, 8 is a PLC control cabinet, V1, V2, V3, V4, V5, V6, and V7 are diaphragm valves, F1 is a high-precision ultrapure filter, and C1 is a one-way valve. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and examples. The purifier 6 used in the example is a 7NG060R-2 purifier produced by Semper Semiconductor Technology (Shanghai) Co., Ltd. The vacuum gauge is a cold cathode ionization vacuum gauge, and the diaphragm valve is a diaphragm valve with remote control.

[0030] Example 1

[0031] The steel cylinder to be processed has a stamp number of 1502207, a capacity of 450L, a cylinder valve type of CGA716, and a gas to be filled with high-purity sulfur hexafluoride. The test gas used is helium.

[0032] Start the cylinder processing program in the PLC and enter the first step: gas detection test. The program prompts to install the cylinder. Click "Confirm Installation". The system automatically opens the diaphragm valve V7 with remote control and analyzes the moisture, oxygen and nitrogen content in the test gas. After testing, the moisture content is 4ppbv, the oxygen content is 0.05ppmv, and the nitrogen content is 0.05ppbv. Click "Test Passed". The program automatically closes the diaphragm valve V7 with remote control and prompts to enter the next step: vacuum test; the program automatically opens the diaphragm valve V6 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V1 with remote control in turn to test the system vacuum degree. Wait until the reading of the vacuum gauge 3 reaches 10 -8 After reaching 120°C, the program automatically closes the diaphragm valve V6 with remote control and maintains the vacuum degree for 30 minutes. Click "Test Pass" to proceed to the next step: heating the cylinder; start the temperature control module of the cylinder heating blanket 2 in the PLC. After the cylinder automatically heats up to 120°C, the program automatically enters the next step: evacuate; click "evacuate" to open the cylinder valve, and the program automatically opens the diaphragm valve V6 with remote control. Wait until the reading of the vacuum gauge 3 reaches 10 -8Pa, keep for 4h, the program automatically closes the diaphragm valve V1 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V6 with remote control, and prompts to proceed to the next step: cylinder test; click "Test", the program automatically opens the diaphragm valve V5 with remote control, the diaphragm valve V3 with remote control, and the diaphragm valve V1 with remote control, the pressure sensor 4 pressure reaches 55psi, the program automatically closes the diaphragm valve V5 with remote control, and opens the diaphragm valve V4 with remote control, and tests the moisture, oxygen and nitrogen in the cylinder. After testing, the moisture in the cylinder is 39ppbv, the oxygen is 0.06ppmv, and the nitrogen is 0.08ppmv. Click "Pass", the program automatically closes the diaphragm valve V3 with remote control, the diaphragm valve V4 with remote control, and automatically opens the diaphragm valve V6 with remote control and the diaphragm valve V2 with remote control, and waits for the reading of the vacuum gauge 3 to reach 10 -8 Pa, the program prompts that the processing is completed, close the cylinder valve, click the "Finish" button, the program automatically closes the diaphragm valve V6 with remote control, the diaphragm valve V2 with remote control, and the diaphragm valve V1 with remote control, the program automatically turns off the power of the heating blanket, returns to the main interface, and removes the cylinder for use.

[0033] Example 2

[0034] The steel cylinder to be processed has a stamp number of 16B90125, a capacity of 47L, a cylinder valve type of CGA580, and electronic grade carbon tetrafluoride as the gas to be filled. Helium is used as the test gas.

[0035] The control steps were the same as those in Example 1. The test gas analysis showed that the water content was 2 ppbv, the oxygen content was 0.05 ppmv, and the nitrogen content was 0.05 ppbv. The cylinder was qualified.

[0036] Example 3

[0037] The steel cylinder to be processed has a stamp number of D2931107, a volume of 44L, a cylinder valve type of CGA640, and the gas to be filled is electronic grade nitrogen trifluoride. The test gas part uses argon.

[0038] The operation steps are the same as those in Example 1. The test gas test analysis shows that the water content is 6 ppbv, the oxygen content is 0.03 ppmv, and the nitrogen content is 0.06 ppbv. The steel cylinder is qualified.

[0039] Example 4

[0040] The steel cylinder to be processed has a stamp number of B07008, a capacity of 40L, a cylinder valve type of CGA638, and the gas to be filled is electronic grade tungsten hexafluoride. The gas part uses argon.

[0041] The control steps were the same as those in Example 1. The test gas analysis showed that the water content was 7 ppbv, the oxygen content was 0.04 ppmv, and the nitrogen content was 0.05 ppbv. The cylinder was qualified.

[0042] The treatment results of the steel cylinders in each embodiment are shown in Table 1.

[0043] Table 1 Treatment results of steel cylinders in the examples

[0044]

Claims

1. A cylinder processing system, comprising four units, first, a cylinder unit: one or more cylinders wrapped with a heating blanket, a diaphragm valve, a vacuum gauge and a pressure sensor; second, an analysis unit: comprising a diaphragm valve and an analysis device; third, a test gas unit: comprising a diaphragm valve, a one-way valve, a filter and a purification device; fourth, an evacuation unit: comprising a diaphragm valve and a vacuum device; a main pipe coming out of the cylinder (1) is connected in sequence with a first diaphragm valve (V1), a vacuum gauge (3), a pressure sensor (4), an analysis unit, a test gas unit and a vacuum device; A gas unit and an evacuation unit; a vacuum gauge (3) is connected to the main pipeline through a second diaphragm valve (V2), and a pressure sensor (4) is connected to the main pipeline through a third diaphragm valve (V3); an analysis device (5) is connected to the main pipeline through a fourth diaphragm valve (V4), and is connected to the test gas unit through a seventh diaphragm valve (V7); a purification device (6) is connected to the main pipeline through a filter (F1), a one-way valve (C1), and a fifth diaphragm valve (V5) in sequence; and a vacuum device (7) is connected to the main pipeline through a sixth diaphragm valve (V6).

2. The cylinder processing system according to claim 1, wherein the vacuum gauge is a cold cathode ionization vacuum gauge.

3. According to claim 2, the cylinder processing system further comprises a PLC control cabinet (8), the PLC control cabinet (8) comprises a cylinder processing program, a temperature control module of the heating blanket (2), the heating blanket (2), the vacuum gauge (3) and the pressure sensor (4) are connected to the PLC control cabinet (8), the PLC control cabinet (8) controls the cylinder temperature and the opening and closing of the diaphragm valve, and the diaphragm valve is a diaphragm valve with remote control.

4. According to the cylinder processing system described in claim 2, the minimum detection limit of moisture of the analysis equipment (5) is not more than 2ppbv, the minimum detection limit of oxygen is not more than 0.01ppmv, and the minimum detection limit of nitrogen is not more than 0.01ppmv.

5. According to the steel cylinder processing system of claim 2, the contents of moisture, oxygen and nitrogen in the test gas purified by the purification equipment (6) are less than 10 ppbv.

6. According to the cylinder processing system of claim 2, the vacuum equipment (7) is composed of a two-stage pump, the front pump is a Roots pump, the secondary pump is a turbomolecular pump, and the vacuum degree reaches 10 -8 Pa.

7. According to the cylinder processing system of claim 2, the pipelines connecting the various units and equipment are EP grade stainless steel pipes, the filters are high-precision ultra-clean filters, the one-way valves are EP grade, the pipelines are connected with EP grade welding joints, and the entire system is connected with metal face sealing (VCR) joints and orbital automatic welding technology (TIG).

8. A method for using the cylinder handling system of claim 2, comprising the following steps: (1) Test gas test: Analyze the test gas purified by the purification equipment with an analytical device. If the moisture, oxygen and nitrogen content in the test gas is less than 10ppbv, it is qualified; (2) Vacuum test: Test the vacuum degree of the cylinder and wait until the reading of the vacuum gauge (3) reaches 10. -8 After Pa, disconnect the vacuum equipment and keep the vacuum degree for 30 minutes without decreasing, the vacuum degree is qualified; (3) Heating the cylinder: The cylinder is heated to a set temperature by means of a heating blanket (2), and the temperature control range of the cylinder is 100 to 120°C; (4) Evacuate: Connect the cylinder to the vacuum equipment and wait until the reading on the vacuum gauge (3) reaches 10. -8 Pa, maintain for 4h, and turn off the vacuum equipment; (5) Cylinder test: Introduce the test gas from the purification equipment into the cylinder. When the pressure of the pressure sensor reaches 50-100 psi, stop the gas supply. Use the analysis equipment to analyze the moisture, oxygen and nitrogen content in the test cylinder. If the moisture is less than 50 ppbv, the oxygen is less than 0.10 ppmv, and the nitrogen is less than 0.10 ppmv, it is considered "qualified". Turn off the test equipment and connect the vacuum equipment. Wait until the vacuum gauge reading reaches 10 -8 When the cylinder valve and heating blanket are closed, the cylinder treatment is completed; if the moisture, oxygen and nitrogen test values ​​are unqualified, return to step (4) and re-process.

9. A method for using the cylinder handling system according to claim 3, comprising the following steps: (1) Gas testing: Start the cylinder processing program in the PLC control cabinet (8), and the system automatically opens the seventh diaphragm valve (V7) with remote control to analyze the moisture, oxygen and nitrogen content in the test gas. If the analysis values ​​are all lower than 10 ppbv, it is qualified. The program automatically closes the seventh diaphragm valve (V7) with remote control and enters the vacuum test program; (2) Vacuum test: The program automatically opens the sixth diaphragm valve with remote control (V6), the second diaphragm valve with remote control (V2), and the first diaphragm valve with remote control (V1) in sequence to test the system vacuum degree. When the reading of the vacuum gauge (3) reaches 10 -8 After Pa, the program automatically closes the sixth diaphragm valve (V6) with remote control and maintains it for 30 minutes. If the vacuum degree does not decrease, click the "Test Pass" button to enter the cylinder heating program. If the vacuum degree decreases during the test, the program alarms, reinstalls the cylinder connector, and clicks "Return". The program repeats step (2). (3) Heating of the cylinder: Start the temperature control module of the heating blanket (2) in the PLC, and the cylinder will automatically heat up to the set temperature and then enter the evacuation program; (4) Evacuate: Click the "Evacuate" button to open the cylinder valve. The program will automatically open the sixth diaphragm valve (V6) with remote control. Wait until the reading on the vacuum gauge (3) reaches 10. -8 Pa, maintained for 4 hours, the program automatically closes the first diaphragm valve with remote control (V1), the second diaphragm valve with remote control (V2), and the sixth diaphragm valve with remote control (V6) in sequence, and enters the cylinder test program; (5) Cylinder test: Click the "Test" button, the program automatically opens the fifth diaphragm valve (V5) with remote control, the third diaphragm valve (V3) with remote control, and the first diaphragm valve (V1) with remote control in sequence. When the pressure of the pressure sensor (4) reaches 50-100 psi, the program automatically closes the fifth diaphragm valve (V5) with remote control and opens the fourth diaphragm valve (V4) with remote control to test the moisture, oxygen and nitrogen in the cylinder. When the moisture is less than 50 ppbv, the oxygen is less than 0.10 ppmv, and the nitrogen is less than 0.10 ppmv, click the "Pass" button, the program automatically closes the third diaphragm valve (V3) with remote control, the fourth diaphragm valve (V4) with remote control, and automatically opens the sixth diaphragm valve (V6) with remote control and the second diaphragm valve (V2) with remote control. When the reading of the vacuum gauge (3) reaches 10 -8 Pa, the program prompts that the processing is completed, close the cylinder valve, click the "Finish" button, the program automatically closes the sixth diaphragm valve (V6) with remote control, the second diaphragm valve (V2) with remote control, and the first diaphragm valve (V1) with remote control, and the program automatically turns off the power of the heating blanket and returns to the PLC main interface; if the moisture, oxygen and nitrogen test values ​​are unqualified, the program alarms, click the "Unqualified" button, and the program automatically returns to step (4) for reprocessing.

10. Use of a steel cylinder treated according to the method of claim 8 or 9 in electronic gas.

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