A chlorine trifluoride filling system and filling method

Abstract

The present invention relates to the field of fine chemical technology, and in particular to a chlorine trifluoride filling system and filling method, which aims to solve the problem that the leakage of extremely small amounts of chlorine trifluoride cannot be effectively judged. The chlorine trifluoride filling system provided by the present invention comprises a vacuuming pipeline, a purge pipeline and a filling pipeline arranged in parallel; the vacuuming pipeline is used to vacuumize the system, the purge pipeline is used to blow gas into the system, and the filling pipeline is used to blow chlorine trifluoride. The chlorine trifluoride filling system provided by the present invention performs vacuuming through the vacuuming pipeline and blowing nitrogen into the purge pipeline to achieve gas purging, and the two are performed alternately and reach a certain number of times to remove chlorine trifluoride and other gases in the system, ensuring that only nitrogen is present when replacing the steel cylinder for storing chlorine trifluoride. At the same time, positive pressure maintenance and negative pressure maintenance can be performed before and after filling chlorine trifluoride to achieve airtightness detection, ensuring that there is no leakage in the system, and ensuring the sealing and safety of each filled product.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemicals, and in particular to a chlorine trifluoride filling system and a filling method. Background Art

[0002] Chlorine trifluoride is a colorless corrosive gas or a pale yellow liquid with a liquid density of 1.825 g / cm 3 , melting point -76.34℃, boiling point 11.75℃. Easily soluble in anhydrous hydrogen fluoride, carbon tetrachloride, etc. Chlorine trifluoride is a strong oxidant with high chemical reactivity. It is one of the most active compounds known. It can react explosively with water and organic compounds and is a hazardous chemical. In recent years, with the rapid development of the semiconductor, liquid crystal, solar energy and LED industries, chlorine trifluoride has been widely used in CVD (chemical vapor deposition chamber) cleaning, wafer etching and other process links, and the demand is on the rise. Chlorine trifluoride has become one of the key special gases in the semiconductor industry. In addition, chlorine trifluoride is also used as a fluorinating agent, combustion agent and propellant, high-temperature metal cutting oil, etc.

[0003] When high-purity chlorine trifluoride products are filled into steel cylinders, the filling pipe will be exposed to a dual gas environment of air and chlorine trifluoride. Although the pipeline has been passivated, the repeated changes in the gas environment will lead to the destruction of the passivation film, thereby aggravating the corrosion. Therefore, the filling system should be verified for air tightness during each filling operation during the process operation. In addition, the corrosion rate of equipment such as corroded pipes and valve components is extremely slow. The fluctuation of the pressure gauge value in ordinary processes cannot show whether the system has leakage. Once a leak occurs, it will not only affect the product quality, but also easily cause major safety accidents.

[0004] Patent CN116658802B discloses a method and system for determining whether a filling system is leaking by obtaining the pressure value in a sealed space in real time through a pressure gauge. The disadvantage is that when chlorine trifluoride leaks, the amount is extremely small, and the pressure gauge value does not change significantly, so the leakage of chlorine trifluoride cannot be effectively determined. Summary of the invention

[0005] The object of the present invention is to provide a chlorine trifluoride filling system and filling method to solve the problem that a very small amount of leakage of chlorine trifluoride cannot be effectively judged.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] A chlorine trifluoride filling system comprises a vacuum pipeline, a purge pipeline and a filling pipeline arranged in parallel;

[0008] The vacuum pipeline is used to vacuum the system, the purge pipeline is used to blow gas into the system, and the filling pipeline is used to blow chlorine trifluoride.

[0009] Further, the vacuum extraction pipeline includes a vacuum generator branch and a vacuum pump branch arranged in parallel, the vacuum generator branch includes a vacuum generator, and the vacuum pump branch includes a first vacuum pump;

[0010] Nitrogen is introduced into the vacuum generator to form a partial vacuum at the vacuum generator; then the vacuum generator works to reduce the system pressure to a set value, and finally the vacuum generator is closed and the first vacuum pump is turned on to reduce the system pressure to a desired value.

[0011] Furthermore, the vacuum generator branch also includes a first micro-leakage valve and a first check valve; the nitrogen gas passes through the first micro-leakage valve and the first check valve in sequence and then reaches the vacuum generator;

[0012] The purge pipeline includes a second micro-leakage valve, a nitrogen valve and a nitrogen inlet valve which are connected in sequence, and the nitrogen passes through the second micro-leakage valve, the nitrogen valve and the nitrogen inlet valve in sequence.

[0013] Furthermore, the chlorine trifluoride filling system also includes a storage pipeline, which is connected to the vacuum pipeline, the purge pipeline and the filling pipeline;

[0014] The storage pipeline comprises a storage tank, and the storage tank is used to store chlorine trifluoride.

[0015] Further, the storage tank includes a main tank body and a second vacuum pump, and the main tank body includes a vacuum tank body, a storage tank body and a temperature control tube;

[0016] The storage tank body is installed in the vacuum tank body and forms a vacuum interlayer with the vacuum tank body, and the temperature control tube is arranged in the vacuum interlayer and is wound and installed on the outer wall of the storage tank body;

[0017] A flowing liquid is introduced into the temperature control tube;

[0018] The second vacuum pump is communicated with the vacuum interlayer, and when the vacuum degree of the vacuum interlayer decreases to a set value, the second vacuum pump is started.

[0019] Furthermore, the storage tank further comprises a control assembly, and the control assembly comprises a control box and a slider;

[0020] The outlet of the second vacuum pump is connected to the control box, and the slider is disposed in the control box and is slidably connected to the control box;

[0021] The sliding block is provided with an exhaust hole and an exhaust groove. The gas extracted by the second vacuum pump enters the control box and passes through the exhaust hole and the exhaust groove in sequence before being discharged from the control box.

[0022] Furthermore, the storage tank also includes a spare tank body, and the control assembly also includes a three-way valve, a connecting rod and a connecting frame;

[0023] The three-way valve is connected to the vacuum interlayer, the storage tank and the second vacuum pump respectively, and the outlet of the control box is connected to the spare tank;

[0024] One end of the connecting rod is hinged to the connecting frame, and the other end is hinged to the handle of the three-way valve, and the connecting frame is slidably connected to the control box;

[0025] The gas in the vacuum interlayer sequentially enters the control box through the three-way valve and the second vacuum pump to push the slider to move, and then the slider abuts against the inner wall of the control box to block the exhaust groove and connect the exhaust hole with the outlet of the control box; at the same time, the slider pushes the connecting frame to move so that the connecting rod drives the handle of the three-way valve to rotate, so that the storage tank is connected with the second vacuum pump;

[0026] At this time, the second vacuum pump extracts the gas in the storage tank, and the gas passes through the three-way valve, the second vacuum pump, the control box, and the exhaust hole in sequence and then enters the spare tank.

[0027] Furthermore, the control assembly also includes a return spring and a magnet;

[0028] The return spring and the magnet are respectively arranged at both ends of the slider, and the magnet is installed on the control box; the return spring is used to apply a pulling force to the slider to make the slider move away from the magnet; the magnet is used to attract the slider so that the slider abuts against the inner wall of the control box, so that the exhaust groove is closed.

[0029] Furthermore, the control component also includes an auxiliary valve, which is connected to the vacuum interlayer; the connecting frame moves to push the handle of the auxiliary valve to rotate, thereby opening the auxiliary valve.

[0030] Another aspect of the present invention provides a chlorine trifluoride filling method, using the above-mentioned chlorine trifluoride filling system, comprising the following steps:

[0031] Bottle replacement and purging: The vacuum pipeline is used to evacuate the system pressure to the set negative pressure value, and the purge pipeline is used to fill nitrogen into the system to raise the system pressure to the set positive pressure value. This is a purge cycle; the purge cycle is performed for a set number of times. When the last purge is completed, the system maintains a positive pressure environment to prevent air from entering the system.

[0032] Filling and purging: Connect the cylinder to the filling system, and perform the first purge, positive pressure maintenance, second purge, product filling, third purge, negative pressure maintenance and fourth purge in sequence;

[0033] The operation of the four purges is the same as the bottle-changing purge; after the first purge, the pressure in the system is positive, and then positive pressure is maintained; after the second purge, the nitrogen pressure in the system is negative, and then chlorine trifluoride is filled into the cylinder through the filling pipeline; after the third purge, the pressure in the system is negative, and then negative pressure is maintained; after the fourth purge, the pressure in the system is positive.

[0034] Based on the above technical solutions, the technical effects that can be achieved by the present invention are:

[0035] The chlorine trifluoride filling system provided by the present invention comprises a vacuuming pipeline, a purge pipeline and a filling pipeline which are arranged in parallel; the vacuuming pipeline is used for vacuuming the system, the purge pipeline is used for blowing gas into the system, and the filling pipeline is used for blowing chlorine trifluoride.

[0036] The chlorine trifluoride filling system provided by the present invention performs gas purging by vacuumizing a vacuum pipeline and blowing nitrogen into a purge pipeline. The two are performed alternately and a certain number of times can remove chlorine trifluoride and other gases in the system, ensuring that only nitrogen is present in the system before replacing a steel cylinder for storing chlorine trifluoride and before filling chlorine trifluoride. At the same time, positive pressure maintenance and negative pressure maintenance can be performed before and after filling chlorine trifluoride to achieve air tightness detection, ensuring that the system has no leakage, and ensuring the sealing and safety of each filled product. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the structure of a chlorine trifluoride filling system provided in an embodiment of the present invention;

[0039] Figure 2 It is a structural schematic diagram of a storage tank;

[0040] Figure 3 This is a schematic diagram of the structure of the main tank;

[0041] Figure 4 It is a schematic diagram of the structure of the control component;

[0042] Figure 5 is another structural schematic diagram of the control component;

[0043] Figure 6 is a cross-sectional schematic diagram of a control box;

[0044] Figure 7 A schematic cross-sectional view of a slider.

[0045] Icons: 101, first micro-leakage valve; 102, first check valve; 103, vacuum generator; 104, vacuum generator valve; 201, first vacuum pump; 202, vacuum pump valve; 301, vacuum pipeline valve; 401, second micro-leakage valve; 402, nitrogen valve; 403, nitrogen inlet valve; 501, chlorine trifluoride inlet valve; 601, storage inlet valve; 602, metal hose; 603, storage tank; 604, refrigeration jacket; 70, tail gas system;

[0046] 100, main tank body; 110, vacuum tank body; 120, storage tank body; 130, temperature control tube; 140, first valve; 150, second valve; 160, discharge pipe; 170, feed pipe; 180, recovery pipe; 190, pressure valve; 10, vacuum interlayer;

[0047] 200, a second vacuum pump;

[0048] 300, control assembly; 310, control box; 320, slider; 330, three-way valve; 340, connecting rod; 350, connecting frame; 360, return spring; 370, magnet; 380, auxiliary valve; 321, exhaust hole; 322, exhaust groove. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0052] When high-purity chlorine trifluoride products are filled into steel cylinders, the filling pipe will be exposed to a dual gas environment of air and chlorine trifluoride. Although the pipeline has been passivated, the repeated changes in the gas environment will cause the passivation film to be damaged, thereby aggravating corrosion. Therefore, the filling system should be verified for air tightness during each filling operation. The pressure gauge value fluctuations of ordinary processes cannot show whether the system has leaks, and cannot effectively judge extremely small leaks.

[0053] In view of this, the present invention provides a chlorine trifluoride filling system, comprising a vacuum pipeline, a purge pipeline and a filling pipeline arranged in parallel; the vacuum pipeline is used to vacuum the system, the purge pipeline is used to blow gas into the system, and the filling pipeline is used to blow chlorine trifluoride.

[0054] The chlorine trifluoride filling system provided by the present invention performs gas purging by vacuumizing a vacuum pipeline and blowing nitrogen into a purge pipeline. The two are performed alternately and a certain number of times can remove chlorine trifluoride and other gases in the system, ensuring that only nitrogen is present in the system before replacing a steel cylinder for storing chlorine trifluoride and before filling chlorine trifluoride. At the same time, positive pressure maintenance and negative pressure maintenance can be performed before and after filling chlorine trifluoride to achieve air tightness detection, ensuring that the system has no leakage, and ensuring the sealing and safety of each filled product.

[0055] The following combination Figure 1-Figure 7 The structure and shape of the chlorine trifluoride filling system provided in this embodiment are described in detail:

[0056] In this embodiment, the chlorine trifluoride filling system includes a vacuum pipeline, a purge pipeline, a filling pipeline and a storage pipeline. The vacuum pipeline includes a vacuum generator branch, a vacuum pump branch and a vacuum pipeline valve 301. The vacuum generator branch and the vacuum pump branch are connected in parallel to the vacuum pipeline valve 301, and the vacuum pipeline valve 301 is connected to the storage pipeline. The vacuum pipeline, the purge pipeline and the filling pipeline are arranged in parallel and connected to the storage pipeline.

[0057] In this embodiment, the vacuum generator branch includes a first micro-leakage valve 101, a first check valve 102, a vacuum generator 103 and a vacuum generator valve 104 connected in sequence, and the nitrogen passes through the first micro-leakage valve 101 and the first check valve 102 in sequence to reach the vacuum generator 103 and is discharged into the exhaust system 70; the vacuum pump branch includes a first vacuum pump 201 and a vacuum pump valve 202 connected in sequence. The purge pipeline includes a second micro-leakage valve 401, a nitrogen valve 402 and a nitrogen inlet valve 403 connected in sequence, and the nitrogen passes through the second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403 in sequence for purging. The filling pipeline includes a chlorine trifluoride inlet valve 501. The storage pipeline includes a storage inlet valve 601, a metal hose 602 and a storage tank 603 connected in sequence, and the storage tank 603 is used to store chlorine trifluoride.

[0058] In this embodiment, the storage tank 603 can be set as a steel cylinder. When the storage tank 603 is set as a steel cylinder, the storage pipeline includes a refrigeration jacket 604, and the refrigeration jacket 604 is used to cool the steel cylinder.

[0059] In this embodiment, at least two parallel storage pipelines are provided to simultaneously perform the filling task of two storage tanks 603, thereby improving production efficiency.

[0060] In this embodiment, the storage tank 603 includes a main tank body 100, a second vacuum pump 200, a control component 300 and a spare tank body such as Figure 2 shown.

[0061] Specifically, the main tank body 100 includes a vacuum tank body 110, a storage tank body 120, a temperature control tube 130, a first valve 140, a second valve 150, a discharge pipe 160, a feed pipe 170, a recovery pipe 180 and a pressure valve 190. Figure 3 As shown. The storage tank 120 is used to store chlorine trifluoride. The storage tank 120 is installed in the vacuum tank 110 and forms a vacuum interlayer 10 with the vacuum tank 110. The temperature control tube 130 is arranged in the vacuum interlayer 10 and is wound and installed on the outer wall of the storage tank 120. The temperature control tube 130 is passed through the flowing liquid. The discharge pipe 160, the feed pipe 170 and the recovery pipe 180 are all connected to the storage tank 120 for gas circulation. The discharge pipe 160 is provided with a first valve 140, the feed pipe 170 is provided with a second valve 150, and the recovery pipe 180 is provided with a pressure valve 190.

[0062] In this embodiment, the control assembly 300 includes a control box 310, a slider 320, a three-way valve 330, a connecting rod 340, a connecting frame 350, a return spring 360, a magnet 370 and an auxiliary valve 380. Figure 3 , Figure 4 , Figure 5 , Figure 6 shown.

[0063] The second vacuum pump 200 is disposed between the three-way valve 330 and the control box 310. The three-way valve 330 is used to connect the vacuum interlayer 10, the recovery pipe 180 and the second vacuum pump 200. The outlet of the control box 310 is connected to the spare tank. The slider 320 is arranged in the control box 310 and is slidably connected to the control box 310; the control box 310 is also provided with an exhaust port, and the slider 320 is provided with an exhaust hole 321 and an exhaust groove 322; one end of the connecting rod 340 is hinged to the connecting frame 350, and the other end is hinged to the handle of the three-way valve 330, and the connecting frame 350 is slidably connected to the control box 310; the return spring 360 and the magnet 370 are respectively arranged at both ends of the slider 320, and the return spring 360 is used to apply a pulling force to the slider 320 to make the slider 320 away from the magnet 370; the magnet 370 is installed on the control box 310, and is used to attract the slider 320 so that the slider 320 abuts against the inner wall of the control box 310 to block the exhaust groove 322; the auxiliary valve 380 is connected to the vacuum interlayer 10. Among them, the exhaust hole 321 is an L-shaped hole, and the connecting frame 350 is a J-shaped structure.

[0064] When the second vacuum pump 200 extracts a small amount of gas, the gas enters the control box 310 and passes through the exhaust hole 321 and the exhaust groove 322 in sequence before being discharged from the exhaust port. The pulling force of the return spring 360 can keep the exhaust groove 322 connected with the exhaust port, so as to avoid the second vacuum pump 200 repeatedly pumping gas and gradually pushing the slider 320, so that the slider 320 abuts against the inner wall of the control box 310, and then the exhaust groove 322 is blocked. When the second vacuum pump 200 extracts more gas, the slider 320 overcomes the pulling force of the return spring 360 and slides under the push of the gas. After the slider 320 moves a certain distance, the magnet 370 attracts the slider 320 to ensure that the slider 320 abuts against the inner wall of the control box 310, thereby completing the blocking of the exhaust groove 322, and the exhaust hole 321 is connected with the outlet of the control box 310. At the same time, after the slider 320 moves a certain distance, it can push the connecting frame 350 to move so that the connecting rod 340 swings, and then the connecting rod 340 drives the handle of the three-way valve 330 to rotate, so that the three-way valve 330 switches the connection state, and the storage tank body 120 is connected with the second vacuum pump 200. At this time, the second vacuum pump 200 extracts the gas in the storage tank body 120, and the gas passes through the three-way valve 330, the second vacuum pump 200, the control box 310, and the exhaust hole 321 in turn and then enters the spare tank body.

[0065] As the connecting frame 350 moves, the connecting frame 350 pushes the handle of the auxiliary valve 380 to rotate so that the auxiliary valve 380 is opened. At this time, the gas in the vacuum interlayer 10 can be pumped into the storage container by setting a third vacuum pump to avoid leakage.

[0066] In this embodiment, the working process of the storage tank 603 is as follows:

[0067] The vacuum interlayer 10 provides a vacuum environment to achieve heat preservation; when releasing chlorine trifluoride, a medium at room temperature or a temperature sufficient to convert chlorine trifluoride from liquid to gas flows in the temperature control tube 130, and at this time, the first valve 140 is opened to facilitate the subsequent packaging and use of chlorine trifluoride. When filling chlorine trifluoride into the storage tank 120, a cooling medium is introduced into the temperature control tube 130 to reduce the temperature.

[0068] In the initial state, the three-way valve 330 connects the vacuum interlayer 10 with the second vacuum pump 200. A pressure sensor is provided on the pipeline connecting the three-way valve 330 and the vacuum interlayer 10. The pressure sensor is used to monitor the vacuum degree of the vacuum interlayer 10. When the vacuum degree of the vacuum interlayer 10 is reduced to a set value, the second vacuum pump 200 is started to extract the gas in the vacuum interlayer 10. The gas passes through the exhaust hole 321 and the exhaust groove 322 in sequence and is discharged from the exhaust port, thereby maintaining the vacuum degree of the vacuum interlayer 10. When the vacuum tank body 110 and the storage tank body 120 are not damaged, the gas extracted by the second vacuum pump 200 is small, and the gas is not enough to push the slider 320 a long distance. The slider 320 cannot move to the range of attraction of the magnet. At the same time, the reset spring 360 can reset the slider 320 in time, and the gas is discharged through the exhaust hole 321 and the exhaust groove 322.

[0069] If at least one of the vacuum tank body 110 and the storage tank body 120 is damaged, more gas will enter the vacuum interlayer 10, and the second vacuum pump 200 can continuously draw the gas in the vacuum interlayer 10 into the control box 310. Since the amount of gas delivered by the second vacuum pump 200 is much larger than the discharge amount of the exhaust groove 322, the gas pushes the slider 320 to move and overcome the pulling force of the return spring 360. Finally, the slider 320 abuts against the inner wall of the control box 310 under the action of gas push and magnet 370 attraction, so that the exhaust groove 322 is blocked and the exhaust hole 321 is connected to the spare tank body. At the same time, the slider 320 pushes the connecting frame 350 to move so that the connecting frame 350 drives the connecting rod 340 to swing, thereby driving the handle of the three-way valve 330 to rotate until the storage tank body 120 is connected to the second vacuum pump 200, and the vacuum interlayer 10 is disconnected from the second vacuum pump 200. At this time, the second vacuum pump 200 operates to generate negative pressure to break through the pressure value of the pressure valve 190, thereby extracting the gas stored in the storage tank body 120, and the gas enters the spare tank body through the exhaust hole 321 to realize the timely transfer of the gas.

[0070] When the connecting frame 350 moves, the connecting frame 350 pushes the handle of the auxiliary valve 380 to rotate so that the auxiliary valve 380 opens, so that the third vacuum pump can draw the gas in the vacuum interlayer 10 into the storage container for treatment, so as to avoid chlorine trifluoride entering the vacuum interlayer 10 and being unable to be treated when the storage tank body 120 is damaged.

[0071] In addition, a switch may be provided on the connecting frame 350. When the connecting frame 350 is moved, the temperature of the medium in the temperature control tube 130 may be controlled to increase, thereby accelerating the temperature rise of chlorine trifluoride to increase the transfer speed of the gas.

[0072] Based on the chlorine trifluoride filling system provided in this embodiment, a chlorine trifluoride filling method is proposed, using the above-mentioned chlorine trifluoride filling system, comprising the following steps:

[0073] Bottle replacement and purging: The vacuum pipeline is used to evacuate the system pressure to the set negative pressure value, and the purge pipeline is used to fill nitrogen into the system to raise the system pressure to the set positive pressure value. This is a purge cycle; the purge cycle is performed for a set number of times. When the last purge is completed, the system maintains a positive pressure environment to prevent air from entering the system.

[0074] Filling and purging: Connect the cylinder to the filling system, and perform the first purge, positive pressure maintenance, second purge, product filling, third purge, negative pressure maintenance and fourth purge in sequence;

[0075] The operation of the four purges is the same as the bottle change purge; after the first purge, the pressure in the system is positive, and then positive pressure is maintained; after the second purge, the nitrogen pressure in the system is negative, and then chlorine trifluoride is filled into the cylinder through the filling pipeline; after the third purge, the pressure in the system is negative, and then negative pressure is maintained; after the fourth purge, the system maintains a positive pressure environment to prevent air from entering the system.

[0076] The specific steps of the chlorine trifluoride filling method provided in this embodiment are as follows, wherein the storage tank 603 is set as a steel cylinder:

[0077] S100 Bottle exchange and purging: Automatically close the chlorine trifluoride inlet valve 501 and open the first micro-leakage valve 101 and the first check valve 102, fill high-purity nitrogen into the vacuum generator 103, and form a partial vacuum at the vacuum generator 103. Then automatically open the vacuum generator valve 104 and the vacuum pipeline valve 301 to pump the chlorine trifluoride in the filling system to -0.08MPa, then automatically close the vacuum generator valve 104 and open the vacuum pump valve 202 to pump the chlorine trifluoride in the filling system to -0.095MPa, and then automatically close the vacuum pump valve 202 and the vacuum pipeline valve 301. Then automatically open the second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403, fill high-purity nitrogen until the pressure in the system is 0.02MPa, and then automatically close the second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403, so as to form a purging cycle. The system was purged 100 times in total to completely purge out the chlorine trifluoride in the filling system.

[0078] When the last purge is completed, keep the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403 open to form a micro-positive pressure environment of nitrogen in the filling system pipeline to prevent air from entering the filling system, and then connect the pretreated cylinder to the filling system.

[0079] S200 replacement of cylinders: After the cylinders are connected to the filling system, the filling mass is set to 20kg according to the tare weight of the cylinders.

[0080] S300 filling and purging: Connect the cylinder to the filling system and perform the first purge, positive pressure maintenance, second purge, product filling, third purge, negative pressure maintenance and fourth purge in sequence.

[0081] S310 First purge: automatically close the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403, open the first micro-leakage valve 101 and the first check valve 102, fill high-purity nitrogen into the vacuum generator 103, and form a partial vacuum at the vacuum generator 103. Then automatically open the vacuum generator valve 104 and the vacuum pipeline valve 301 to pump the chlorine trifluoride in the filling system to -0.08MPa, then automatically close the vacuum generator valve 104 and open the vacuum pump valve 202 to pump the chlorine trifluoride in the filling system to -0.095MPa, and then automatically close the vacuum pump valve 202 and the vacuum pipeline valve 301. Then, the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403 are automatically opened, and high-purity nitrogen is filled until the pressure in the system is 0.05-0.07 MPa, and then the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403 are automatically closed, which is one purge cycle. A total of 80 purges are performed, and the pressure in the system is 0.067 MPa after the last purge.

[0082] S320 Positive pressure maintenance: automatically open the storage inlet valve 601, close the other valves, maintain the pressure for 1 hour, and the pressure change within 1 hour does not exceed 0.003MPa, the pressure maintenance is qualified. If the pressure change exceeds 0.003MPa, the system will alarm to remind the relevant technical personnel to handle it, such as leak detection, tightening the connection between the cylinder and the pipeline, replacing the valve gasket, etc.

[0083] S330 Second purge: automatically open the first micro-leakage valve 101 and the first check valve 102, fill high-purity nitrogen into the vacuum generator 103, and form a partial vacuum at the vacuum generator 103. Then automatically open the vacuum generator valve 104 and the vacuum pipeline valve 301 to pump the chlorine trifluoride in the filling system to -0.08MPa, then automatically close the vacuum generator valve 104, automatically open the vacuum pump valve 202, pump the chlorine trifluoride in the filling system to -0.095MPa, and then automatically close the vacuum pump valve 202 and the vacuum pipeline valve 301. The second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403 are automatically opened, and high-purity nitrogen is filled until the pressure in the system is 0.05-0.07MPa. The second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403 are automatically closed. This is one purge cycle. A total of 80 purges are performed. When the last purge is completed, the pressure in the system is -0.098MPa.

[0084] S340 product filling: automatically open the chlorine trifluoride inlet valve 501 and storage inlet valve 601, open the manual valve of the cylinder to fill the chlorine trifluoride, and when the filling mass reaches 20kg, the filling system automatically closes the chlorine trifluoride inlet valve 501. The filling system will alarm to remind that the filling is complete, and the technician closes the manual valve of the cylinder to complete the filling.

[0085] S350 The third purge: automatically open the first micro-leakage valve 101 and the first check valve 102, fill the vacuum generator 103 with high-purity nitrogen, and form a partial vacuum at the vacuum generator 103. Then automatically open the vacuum generator valve 104 and the vacuum pipeline valve 301 to pump the chlorine trifluoride in the filling system to -0.08MPa, then automatically close the vacuum generator valve 104 and open the vacuum pump valve 202 to pump the chlorine trifluoride in the filling system to -0.095MPa, and then automatically close the vacuum pump valve 202 and the vacuum pipeline valve 301. The second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403 are automatically opened, and high-purity nitrogen is filled until the pressure in the system is 0.05-0.07 MPa. The second micro-leakage valve 401, the nitrogen valve 402 and the nitrogen inlet valve 403 are automatically closed. This is one purge cycle. A total of 100 purges are performed. When the last purge is completed, the pressure in the system is -0.098 MPa.

[0086] S360 Negative pressure maintenance: The filling system automatically opens the storage inlet valve 601, and the other valves are closed to maintain the pressure for 1 hour. If the pressure change does not exceed 0.003MPa within 1 hour, the pressure maintenance is completed; if the pressure change exceeds 0.003MPa, it means that there is an internal leakage at the connection between the cylinder and the pipeline, and the control system will alarm to remind the relevant technical personnel to handle it, such as evacuating the filling system, replacing the cylinder, etc.

[0087] S360 Fourth purge: The filling system automatically opens the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403, fills high-purity nitrogen until the pressure in the system is 0.02-0.03MPa, and automatically closes the second micro-leakage valve 401, nitrogen valve 402 and nitrogen inlet valve 403. Automatically open the first micro-leakage valve 101 and the first check valve 102, fill high-purity nitrogen into the vacuum generator 103, and form a partial vacuum at the vacuum generator 103. Then automatically open the vacuum generator valve 104 and the vacuum pipeline valve 301, pump the chlorine trifluoride in the filling system to -0.08MPa, then automatically close the vacuum generator valve 104 and automatically open the vacuum pump valve 202, pump the chlorine trifluoride in the filling system to -0.095MPa, and then automatically close the vacuum pump valve 202 and the vacuum pipeline valve 301. This is one purge cycle, and there are 100 purges in total. After the last purge, the pressure in the system is 0.023MPa.

[0088] After the fourth purge is completed, the filling and purging are all completed, and then the bottle replacement purging is carried out, and the cylinder replacement operation is carried out under the condition of slight positive pressure in the pipeline.

[0089] During bottle change purging, the first purging, the second purging, the third purging and the fourth purging, the storage inlet valve 601 is in the closed state; the manual valve of the cylinder is opened only when the product is filled.

[0090] In this embodiment, the cylinder pretreatment operation is as follows:

[0091] After passivation for 36 hours with a gradient concentration of fluorine and nitrogen mixture, the cylinder was heated to remove trace amounts of water to prevent H 2 O and ClF 3 It reacts slowly at room temperature to generate HF, which in turn causes the HF concentration of the product in the cylinder to slowly increase, shortening the shelf life of the product and thus affecting product quality.

[0092] The chlorine trifluoride filling system provided in this embodiment can integrate the control unit into a filling cabinet, and automatically complete related operations, such as opening and closing of valves, by clicking the "bottle change and purge" and "filling and purge" buttons on the filling cabinet operation panel, thereby saving labor and improving efficiency.

[0093] A high-precision electronic scale is used to weigh the tare weight of the cylinder. The electronic scale data is connected to the filling cabinet system, so that the electronic scale value is automatically displayed and filling is automatically stopped according to the electronic scale value.

[0094] Since the corrosion rate of devices and equipment such as pipelines and valve components is extremely slow, the leakage rate is also extremely slow, and the pressure gauge value fluctuations of ordinary processes cannot show whether the system has leaks. The positive pressure maintenance and negative pressure maintenance in this embodiment are both 1 hour. The standard for judging whether there is a leak is whether the pressure change during the pressure maintenance period exceeds 0.003MPa. Long-term pressure maintenance and strict judgment standards can detect trace leaks, which makes up for the defect that ordinary process design cannot judge trace leaks.

[0095] In the filling method provided in this embodiment, positive pressure maintenance and negative pressure maintenance are performed each time the cylinder is filled to detect air tightness, thereby ensuring the sealing and safety of the product filled each time.

[0096] In the filling method provided in this embodiment, both the bottle changing purging and the filling purging operations can be automated. By clicking the corresponding buttons on the filling cabinet operation panel, the purging, pressure maintaining, filling and other operations can be automatically performed. The degree of automation is high, and there is no need for personnel to wait at the production site, which reduces labor costs and improves the safety of personnel operations.

[0097] When the filling system provided in this embodiment is filling one of the cylinders, the other cylinder can be purged and pressure maintained, and then the other cylinder can be filled. The filling tasks of two cylinders can be performed simultaneously, thereby improving production efficiency.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chlorine trifluoride filling system, characterized in that: It includes a vacuum pipeline, a purge pipeline and a filling pipeline arranged in parallel; The vacuum pipeline is used to vacuum the system, the purge pipeline is used to blow gas into the system, and the filling pipeline is used to blow chlorine trifluoride.

2. The chlorine trifluoride filling system according to claim 1, characterized in that: The vacuum extraction pipeline comprises a vacuum generator branch and a vacuum pump branch which are arranged in parallel, the vacuum generator branch comprises a vacuum generator (103), and the vacuum pump branch comprises a first vacuum pump (201); Nitrogen is introduced into the vacuum generator (103) to form a partial vacuum at the vacuum generator (103); then the vacuum generator (103) works to reduce the system pressure to a set value, and finally the vacuum generator (103) is closed and the first vacuum pump (201) is opened to reduce the system pressure to a desired value.

3. The chlorine trifluoride filling system according to claim 2, characterized in that: The vacuum generator branch further comprises a first micro-leakage valve (101) and a first check valve (102); the nitrogen gas passes through the first micro-leakage valve (101) and the first check valve (102) in sequence and then reaches the vacuum generator (103); The purge pipeline comprises a second micro-leakage valve (401), a nitrogen valve (402) and a nitrogen inlet valve (403) which are connected in sequence, and the nitrogen passes through the second micro-leakage valve (401), the nitrogen valve (402) and the nitrogen inlet valve (403) in sequence.

4. The chlorine trifluoride filling system according to claim 3, characterized in that: It also includes a storage pipeline, which is connected to the vacuum pipeline, the purge pipeline and the filling pipeline; The storage pipeline comprises a storage tank (603), and the storage tank (603) is used to store chlorine trifluoride.

5. The chlorine trifluoride filling system according to claim 4, characterized in that: The storage tank (603) comprises a main tank body (100) and a second vacuum pump (200), and the main tank body (100) comprises a vacuum tank body (110), a storage tank body (120) and a temperature control tube (130); The storage tank body (120) is installed in the vacuum tank body (110) and forms a vacuum interlayer (10) with the vacuum tank body (110); the temperature control tube (130) is arranged in the vacuum interlayer (10) and is wound around the outer wall of the storage tank body (120); A flowing liquid is introduced into the temperature control tube (130); The second vacuum pump (200) is in communication with the vacuum interlayer (10), and when the vacuum degree of the vacuum interlayer (10) decreases to a set value, the second vacuum pump (200) is started.

6. The chlorine trifluoride filling system according to claim 5, characterized in that: The storage tank (603) further comprises a control assembly (300), wherein the control assembly (300) comprises a control box (310) and a slider (320); The outlet of the second vacuum pump (200) is connected to the control box (310), and the slider (320) is disposed in the control box (310) and is slidably connected to the control box (310); The slider (320) is provided with an exhaust hole (321) and an exhaust groove (322); the gas extracted by the second vacuum pump (200) enters the control box (310), passes through the exhaust hole (321) and the exhaust groove (322) in sequence, and is then discharged from the control box (310).

7. The chlorine trifluoride filling system according to claim 6, characterized in that: The storage tank (603) further includes a spare tank body, and the control assembly (300) further includes a three-way valve (330), a connecting rod (340) and a connecting frame (350); The three-way valve (330) is connected to the vacuum interlayer (10), the storage tank (120) and the second vacuum pump (200) respectively, and the outlet of the control box (310) is connected to the spare tank; One end of the connecting rod (340) is hinged to the connecting frame (350), and the other end is hinged to the handle of the three-way valve (330); the connecting frame (350) is slidably connected to the control box (310); The gas in the vacuum interlayer (10) enters the control box (310) through the three-way valve (330) and the second vacuum pump (200) in sequence to push the slider (320) to move, and then the slider (320) abuts against the inner wall of the control box (310) to block the exhaust groove (322) and connect the exhaust hole (321) with the outlet of the control box (310); at the same time, the slider (320) pushes the connecting frame (350) to move so that the connecting rod (340) drives the handle of the three-way valve (330) to rotate, thereby connecting the storage tank body (120) with the second vacuum pump (200); At this time, the second vacuum pump (200) extracts the gas in the storage tank (120), and the gas passes through the three-way valve (330), the second vacuum pump (200), the control box (310), the exhaust hole (321) in sequence and then enters the spare tank.

8. The chlorine trifluoride filling system according to claim 7, characterized in that: The control assembly (300) further includes a return spring (360) and a magnet (370); The return spring (360) and the magnet (370) are respectively arranged at two ends of the slider (320), and the magnet (370) is installed on the control box (310); the return spring (360) is used to apply a pulling force to the slider (320) so that the slider (320) is away from the magnet (370); the magnet (370) is used to attract the slider (320) so that the slider (320) abuts against the inner wall of the control box (310), so that the exhaust groove (322) is closed.

9. The chlorine trifluoride filling system according to claim 8, characterized in that: The control assembly (300) further comprises an auxiliary valve (380), wherein the auxiliary valve (380) is connected to the vacuum interlayer (10); the connecting frame (350) moves to push the handle of the auxiliary valve (380) to rotate, thereby opening the auxiliary valve (380).

10. A chlorine trifluoride filling method, characterized in that: The chlorine trifluoride filling system according to any one of claims 1 to 9 comprises the following steps: Bottle replacement and purging: The vacuum pipeline is used to evacuate the system pressure to the set negative pressure value, and the purge pipeline is used to fill nitrogen into the system to raise the system pressure to the set positive pressure value. This is a purge cycle; the purge cycle is performed for a set number of times. When the last purge is completed, the system maintains a positive pressure environment to prevent air from entering the system. Filling and purging: Connect the cylinder to the filling system, and perform the first purge, positive pressure maintenance, second purge, product filling, third purge, negative pressure maintenance and fourth purge in sequence; The operation of the four purges is the same as the bottle-changing purge; after the first purge, the pressure in the system is positive, and then positive pressure is maintained; after the second purge, the nitrogen pressure in the system is negative, and then chlorine trifluoride is filled into the cylinder through the filling pipeline; after the third purge, the pressure in the system is negative, and then negative pressure is maintained; after the fourth purge, the pressure in the system is positive.

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