High-purity magnesium and magnesium alloy material anti-oxidation processing system and environment regulation and control method

Abstract

According to the high-purity magnesium and magnesium alloy material anti-oxidation processing system and the environment regulation and control method, liquid argon is introduced into the inner pipe of the gasifier I for primary gasification to absorb a large amount of heat, so that cold energy is transmitted to circulating protection bin air in the shell through the pipe wall, and then water vapor in the protection bin air is condensed to achieve deep dehumidification; argon obtained through primary gasification is introduced into a gasifier II for complete secondary gasification, the temperature is increased to be close to the environment temperature so as to replace air in a protection bin, and in the replacement process, a sodium taking mechanical arm takes out metal sodium in a sodium storage vehicle so that the metal sodium can synchronously react with oxygen and water in the air in the bin for relatively thorough oxygen and water removal; after replacement is completed, argon supply and positive pressure are maintained in a bypass mode, so that oxygen and water vapor in the environment are removed in advance before magnesium is processed, and ultra-clean protection is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hot forming processes and engineering technologies for magnesium and ultra-low oxygen content environments of high-purity magnesium, and specifically relates to an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials. The present invention also relates to a method for regulating the anti-oxidation processing environment of high-purity magnesium and magnesium alloy materials. Background Art

[0002] The anti-oxidation processing environment for high-purity magnesium and magnesium alloy materials is within a relatively enclosed space. By replacing air with high-purity argon, an inert gas space with argon as the typical gas is constructed. Using argon protection has better effects than traditional high-temperature greenhouse gases (such as sulfur hexafluoride, carbon dioxide, etc.), but there are still the following problems that need to be urgently solved:

[0003] 1) There is still a small amount of oxygen that is difficult to displace and discharge after the argon replaces the air For the argon replacement, the qualified standard for replacement is that the detected purity reaches 97%. In theory, the best situation is that the argon concentration approaches 100%, but in actual gas component replacement, it is very difficult to achieve 100% replacement. After reaching 97%, the argon discharged during replacement is much greater than the air (3%) component, and it takes time and increases the consumption of argon.

[0004] Materials testing revealed that a small amount of oxygen still reacted with the magnesium material. This oxygen was difficult to remove through combustion. The Oxygen Index (OI) is an important indicator of a material's combustion performance. It refers to the minimum oxygen volume fraction required for combustion in an oxygen-nitrogen mixture under specified test conditions. A higher OI indicates a higher oxygen concentration required for combustion, making the material more difficult to burn and exhibiting better flame-retardant properties. Conversely, a lower OI indicates a more flammable material. Generally, materials with an OI < 21% are considered flammable (as air contains approximately 21% oxygen, these materials are easily combustible in air); those with an OI between 21% and 27% are combustible; those between 27% and 32% are flame-retardant; and those with an OI > 32% are highly flame-retardant. After replacement, using argon purity (97% by volume) as a reference, and with air accounting for 3% by volume (of which oxygen accounts for 21%), the calculation is 3% × 0.21 = 0.63%. Considering that the gas composition during replacement may not be strictly according to the air ratio limit, and oxygen may remain at 3%, plus the fluctuation of 97% argon, the worst-case oxygen volume ratio of 5% is used as the limit. Currently, there are almost no conventional combustible materials with an oxygen index of 5%. Therefore, to consume a small amount of oxygen, non-magnesium-based materials such as sodium can be used to react with oxygen first under heating conditions. The reaction between sodium and oxygen is not limited by the oxygen index and can be fully completed. The use of non-magnesium-based materials to react with oxygen is mainly because the reactants of sodium and oxygen are different from those of magnesium and oxygen, which can be detected by methods such as chromatography. If magnesium-based materials were used to react with oxygen first, it might overlap with oxides that may appear in subsequent process experiments, leading to misjudgments.

[0005] 2) After the gas replacement is completed, a small amount of water vapor still remains in the gas. Magnesium metal reacts with water vapor in the air when heated, and can also be oxidized. However, the replacement of air with argon differs from the replacement of water vapor in the air. At the beginning of the replacement, water vapor and air coexist, and dry argon needs to replace both simultaneously. The density difference between argon and air is small, resulting in slow diffusion. However, argon does not contain water vapor, while air contains a large amount of water vapor, causing rapid diffusion due to the density difference. Therefore, during low-speed argon replacement, rapid diffusion caused by the density difference of water vapor passively occurs. Furthermore, when the relative humidity drops below 10%, the replacement becomes more difficult and wastes more argon. Conventional dehumidification methods are inefficient and limited in their methods when controlling relative humidity below 10%. Therefore, methods that consume water vapor need to be considered. Chemical desiccation methods may generate new impurities, and conventional physical methods are already close to their limit at around 10%, unless deep freezing and regasification of air are used. However, for large-volume cryogenic gas separation, this is not economically viable. Compared to argon replacement, water vapor replacement, which affects relative humidity, should utilize common materials to simplify the process.

[0006] In summary, there is an urgent need for innovative methods and supporting structures to address the impact of trace amounts of oxygen and water vapor present after argon gas replaces air on the anti-oxidation processing of high-purity magnesium and magnesium alloy materials. Summary of the Invention

[0007] The purpose of this invention is to provide an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials, which solves the problem that a small amount of oxygen and water vapor still exists in the processing space after the replacement process in the existing method.

[0008] Another objective of this invention is to provide a method for controlling the oxidation processing environment of high-purity magnesium and magnesium alloy materials.

[0009] The first technical solution adopted in this invention is: a high-purity magnesium and magnesium alloy material anti-oxidation processing system, including a protective chamber. A shell-and-tube vaporizer I is connected to one side of the protective chamber through a heat exchange pipe. The inlet end of the inner tube of vaporizer I is connected to a liquid argon gas storage tank. The outlet end of the inner tube of vaporizer I is connected to a vaporizer II. Bypass pipes are connected in parallel at the inlet and outlet ends of the inner tube of vaporizer I. The outlet end of vaporizer II is connected to the bottom of the protective chamber through a pipe. A replacement exhaust port is opened at the top of the protective chamber. A sodium storage cart and a corresponding sodium-retrieving robotic arm are installed inside the protective chamber.

[0010] The first technical solution of the present invention is further characterized in that, The inlet end of the outer shell of vaporizer I is connected to the protective chamber through heat exchange pipe I. A suction pump is connected to heat exchange pipe I. The outlet end of the outer shell of vaporizer I is connected to the protective chamber through heat exchange pipe II. Heat exchange valves are installed on both heat exchange pipe I and heat exchange pipe II. A drain pipe is connected to the bottom of the outer shell of vaporizer I. A drain valve is installed on the drain pipe.

[0011] The inlet end of the inner tube of vaporizer I is connected to the liquid argon storage tank through vaporization pipe I. The outlet end of the inner tube of vaporizer I is connected to vaporizer II through vaporization pipe II. The two ends of the bypass pipe are connected in parallel to vaporization pipe I and vaporization pipe II, respectively. An inlet valve is installed on the section of vaporization pipe I that is connected in parallel with the bypass pipe. An outlet valve is installed on the section of vaporization pipe II that is connected in parallel with the bypass pipe. A bypass valve is installed on the bypass pipe. The outlet end of vaporizer II is connected to the bottom of the protective chamber through an argon pipe. An argon valve I is installed on the argon pipe.

[0012] The sodium storage car consists of a box-shaped body with an opening at the top, which is filled with kerosene. A sodium plate support is installed at the bottom of the car body, and a louvered sodium plate is placed on the sodium plate support below the kerosene level.

[0013] A cover plate is hinged to one side of the top of the vehicle body, located above the opening. The hinged position of the cover plate is inclined downward and fixed to a connecting rod located on one side of the vehicle body. The other end of the connecting rod is hinged to a telescopic cylinder that is hinged to the outer wall of the vehicle body at the bottom.

[0014] An argon gas storage cylinder is fixed on the outer wall of the vehicle body. An argon gas pipe is connected to the argon gas storage cylinder and extends to the kerosene level inside the vehicle body. An argon gas valve II is installed on the argon gas pipe.

[0015] The sodium-removing robotic arm includes a walking frame, on which the robotic arm is fixed. A clamp is fixed to the free end of the robotic arm, and a heating plate is provided on the clamp.

[0016] A circulating fan is fixed on the traveling frame and faces the clamp. Multiple ultrasonic generators are arranged longitudinally at intervals on the inner wall of the protective chamber.

[0017] A hydrogen concentration sensor is installed at the top of the protective chamber, and argon concentration sensors, oxygen concentration sensors, and relative humidity sensors are arranged on the inner wall of the protective chamber.

[0018] The second technical solution adopted in this invention is: a method for controlling the anti-oxidation processing environment of high-purity magnesium and magnesium alloy materials based on the above system, comprising the following steps: Step 1: Pre-treat the air inside the protective chamber to the target temperature and humidity; Step 2: The air in the protective chamber is introduced into the outer shell of vaporizer I, and liquid argon is introduced into the inner tube of vaporizer I for primary vaporization. The vaporization absorbs heat and freezes and dehumidifies the air in the outer shell. The argon in the inner tube is then introduced into vaporizer II for secondary vaporization. The resulting argon is introduced into the protective chamber to replace the air. Step 3: The sodium removal robotic arm takes out the metallic sodium from the sodium storage vehicle and brings it into contact with the air in the protective chamber. The sodium reacts with oxygen and water in the air to remove oxygen and water. Step 4: After switching the liquid argon to the bypass pipeline, it is introduced into vaporizer II for vaporization. The resulting argon gas is then introduced into the protective chamber to replenish gas and maintain positive pressure.

[0019] The beneficial effects of this invention are as follows: The high-purity magnesium and magnesium alloy material anti-oxidation processing system and environmental control method of this invention introduces liquid argon into the inner tube of vaporizer I for primary vaporization to absorb a large amount of heat, allowing the cooling energy to be transferred through the tube wall to the circulating protective chamber air in the outer shell, thereby condensing the water vapor in it to achieve deep dehumidification. Then, the argon obtained from the primary vaporization is introduced into vaporizer II for complete secondary vaporization and heated to near the ambient temperature to replace the air in the protective chamber. During the replacement process, the sodium-removing robotic arm takes out metallic sodium from the sodium storage vehicle and allows it to react synchronously with the oxygen and water in the air in the chamber for relatively thorough deoxygenation and dehydration. After the replacement is completed, the argon supply and positive pressure are maintained through the bypass mode, thereby removing oxygen and water vapor in the environment in advance before processing magnesium, achieving ultra-clean protection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the anti-oxidation processing system for high-purity magnesium and magnesium alloy materials of the present invention; Figure 2This is a schematic diagram of the connection relationship of the shell-and-tube vaporizer I in the anti-oxidation processing system for high-purity magnesium and magnesium alloy materials of the present invention. Figure 3 This is a schematic diagram of the sodium storage vehicle in the anti-oxidation processing system for high-purity magnesium and magnesium alloy materials of the present invention; Figure 4 This is a schematic diagram of the structure of the sodium removal robotic arm in the anti-oxidation processing system for high-purity magnesium and magnesium alloy materials of the present invention.

[0021] In the diagram, 1. Protective chamber, 2. Vaporizer I, 3. Liquid argon storage tank, 4. Vaporizer II, 5. Bypass pipeline, 6. Displacement exhaust vent, 7. Sodium storage vehicle, 8. Sodium extraction robotic arm, 9. Heat exchange pipeline I, 10. Suction pump, 11. Heat exchange pipeline II, 12. Heat exchange valve, 13. Drainage pipeline, 14. Drainage valve, 15. Vaporization pipeline I, 16. Vaporization pipeline II, 17. Inlet valve, 18. Outlet valve, 19. Bypass valve, 20. Argon pipeline, 21. Argon valve I, 22. Ultrasonic generator, 23. Hydrogen concentration sensor, 24. Argon concentration sensor / Oxygen concentration sensor / Relative humidity sensor; 71. Vehicle body, 72. Sodium plate bracket, 73. Sodium plate, 74. Cover plate, 75. Connecting rod, 76. Telescopic cylinder, 77. Argon gas storage cylinder, 78. Argon gas pipe, 79. Argon gas valve II; 81. Walking frame, 82. Robotic arm, 83. Gripper, 84. Circulating fan. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] Example 1 This invention provides an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials, such as... Figure 1 and Figure 2As shown, the device includes a protective chamber 1. A shell-and-tube vaporizer I2 is connected to one side of the protective chamber 1 via a heat exchange pipe. The inlet end of the vaporizer I2's outer shell is connected to the protective chamber 1 via a heat exchange pipe I9, which is connected to a suction pump 10. The outlet end of the vaporizer I2's outer shell is connected to the protective chamber 1 via a heat exchange pipe II11. Both heat exchange pipes I9 and II11 are equipped with heat exchange valves 12. A drain pipe 13 is connected to the bottom of the vaporizer I2's outer shell, and a drain valve 14 is installed on the drain pipe 13. During deep dehumidification, the heat exchange valve 12 is opened and the suction pump 10 is started. At this time, the liquid ammonia in the inner tube of the vaporizer I2 absorbs heat due to its latent heat of vaporization. Air from the protective chamber 1 is sent into the outer shell of the vaporizer I2 via the heat exchange pipe I9, where it encounters cooling, causing the water vapor to condense. The dehydrated air returns to the protective chamber 1 via the heat exchange pipe II11. After liquid accumulates in the outer shell of the vaporizer I2, the drain valve 14 is opened, and the liquid is discharged through the drain pipe 13. If the outer wall of the inner tube of vaporizer I2 becomes too cold and frosted, close the heat exchange valve 12 after deep dehumidification is completed to prevent the evaporation of frost water from affecting the protective chamber 1. After opening the drain valve 14, the frost is discharged through heat exchange with the air.

[0024] The inlet end of the inner tube of vaporizer I2 is connected to a liquid argon storage tank 3 through vaporization pipe I15. The outlet end of the inner tube of vaporizer I2 is connected to vaporizer II4 through vaporization pipe II16. The two ends of the bypass pipe 5 are connected in parallel to vaporization pipe I15 and vaporization pipe II16 respectively. An inlet valve 17 is installed on the section of vaporization pipe I15 that is connected in parallel with bypass pipe 5. An outlet valve 18 is installed on the section of vaporization pipe II16 that is connected in parallel with bypass pipe 5. A bypass valve 19 is installed on bypass pipe 5. The outlet end of vaporizer II4 is connected to the bottom of protective chamber 1 through argon pipe 20. An argon valve I21 is installed on argon pipe 20. A replacement exhaust port 6 is opened at the top of protective chamber 1. During the replacement of air in protective chamber 1 (simultaneously with deep dehumidification), the humidity inside protective chamber 1 is high at the initial stage of replacement, requiring rapid deep dehumidification. Simultaneously, a large amount of argon gas is needed to replace the air. Therefore, inlet valve 17, outlet valve 18, and argon valve I21 are opened, and bypass valve 19 is closed. Liquid argon gas from liquid argon storage tank 3 enters the inner tube of vaporizer I2 via vaporization pipe I15, where it partially vaporizes, absorbing a large amount of heat. This heat is transferred through the pipe wall to the circulating air in protective chamber 1 within the outer shell, causing the water vapor to condense. Argon gas (potentially a gas-liquid two-phase or cryogenic gas) exiting vaporizer I2 enters the ambient temperature vaporizer II4 via vaporization pipe II16, absorbing heat from the atmosphere to completely vaporize the argon gas and raise its temperature to near ambient temperature. It is then introduced into protective chamber 1 from the bottom via argon pipe 20, preventing cryogenic gas from directly entering protective chamber 1 and causing temperature fluctuations or condensation. During the above process, liquid argon... Almost all of the cooling energy from vaporization is used for dehumidification (the outer shell of vaporizer I2 is insulated, preventing cooling loss), maximizing the utilization of cooling energy. At the same time, vaporizer II4 ensures the temperature and stability of the output argon. The argon entering the protective chamber 1 uses the density difference between argon and air to push the air above the argon out through the replacement exhaust port 6 at the top of the protective chamber 1, thus achieving the replacement of air by argon. Once the replacement is complete and the humidity in the protective chamber 1 has dropped to an extremely low level, continuous deep dehumidification is no longer required. It is only necessary to maintain argon supply and positive pressure. At this time, the inlet valve 17 and outlet valve 18 are closed, and the bypass valve 19 is opened. A small amount of liquid argon in the liquid argon storage tank 3 directly enters vaporizer II4 through the bypass pipe 5 for vaporization, and then is sent to the protective chamber 1 through the argon pipe 20, thus avoiding unnecessary cooling loss (because dehumidification is not required at this time), simplifying the process, reducing energy consumption, and ensuring a stable gas supply by vaporizer II4. Thus, by switching valves, the system can flexibly switch between two modes: the replacement stage and the maintenance stage. In the replacement stage, vaporizer I2 and vaporizer II4 are connected in series to achieve tiered utilization of cold energy through staged vaporization. Vaporizer I2 serves as a cold energy recovery dehumidifier, and vaporizer II4 serves as a final vaporization temperature regulator. In the maintenance stage, vaporizer II4 serves as the main gas supply unit on its own.

[0025] The protective chamber 1 is equipped with a sodium storage cart 7 and a corresponding sodium-retrieving robotic arm 8. During the replacement process, when the argon concentration reaches a set value (e.g., 97%), the sodium-retrieving robotic arm 8 removes the metallic sodium from the sodium storage cart 7 and reacts it synchronously with the oxygen and water in the air inside the protective chamber 1 to achieve relatively thorough deoxygenation and dehydration. In the sodium hydroxide and hydrogen gas formed by the reaction, most of the sodium hydroxide settles as large particles after the reaction, and a small portion of the particles can be captured by the FFU (high-efficiency filter with fan) in the protective chamber 1. A small amount of hydrogen gas will rise to the top of the protective chamber 1 due to its low density and will be directly discharged with the exhaust gas during the replacement process. For safety reasons, a hydrogen concentration sensor 23 is installed at the top of the protective chamber 1. When the alarm value is reached, the argon gas supply is accelerated and discharged from the replacement exhaust port 6. Since most of the gas in the replacement space is argon inert gas, a small amount of hydrogen gas will not pose a significant risk. Argon concentration sensor 24, oxygen concentration sensor 24 and relative humidity sensor 24 are arranged on the inner wall of the protective chamber 1 to monitor the real-time parameters of argon, oxygen and water vapor. The specific arrangement height can be arranged according to the working surface, the upper part of the working surface, the lower part of the working surface, the top, etc.

[0026] Through the above methods, the combined effects of argon gas dilution of the air inside the protective chamber 1 and refrigeration dehumidification achieve a synergistic treatment of relative humidity through dilution and refrigeration. This requires only the kinetic energy of airflow circulation, fully utilizing the endothermic effect of liquid argon vaporization. Furthermore, residual oxygen and water vapor are effectively controlled through sodium heating for oxygen removal and chemical reaction for water removal.

[0027] Example 2 This invention provides an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials, based on Example 1, such as... Figure 3 As shown, the sodium storage vehicle 7 preferably has a box-shaped body 71 with an opening at the top. The body 71 is filled with kerosene. A sodium plate support 72 is provided at the bottom of the body 71. A louvered sodium plate 73 is placed on the sodium plate support 72, which is below the kerosene level.

[0028] The box-shaped vehicle body 71 is mostly filled with kerosene, which protects the metallic sodium from reacting with air. The sodium plate 73 is fixed in the box-shaped vehicle body 71 by the sodium plate bracket 72. During the replacement process, the sodium removal robotic arm 8 removes the metallic sodium from the box-shaped vehicle body 71 from the kerosene, allowing it to react synchronously with the oxygen and water in the air in the protective chamber 1 for relatively thorough deoxygenation and dehydration. The use of louvered sodium plates 73 allows airflow to pass through and increases the contact surface.

[0029] Example 3 This invention provides an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials. Based on Example 2, an argon gas storage cylinder 77 is fixed on the outer wall of the vehicle body 71. An argon gas pipe 78 extending from the argon gas storage cylinder 77 to the kerosene surface inside the vehicle body 71 is connected to the argon gas storage cylinder 77. An argon gas valve II 79 is installed on the argon gas pipe 78. During the replacement process, the sodium storage vehicle 7 can simultaneously open the internal replacement, that is, the argon gas valve II 79 opens, and the argon gas in the argon gas storage cylinder 77 is sent into the space above the kerosene surface inside the vehicle body 71 through the argon gas pipe 78 to achieve inert gas protection and prevent the oxygen concentration in the protective chamber 1 from increasing due to air being introduced into the equipment.

[0030] In addition, a cover plate 74 can be hinged to one side of the top of the vehicle body 71, located above the opening. By adding the cover plate 74, the diffusion of volatile kerosene vapor into the protective chamber 1 can be greatly limited, thereby isolating the source of pollution to the greatest extent. The hinge position of the cover plate 74 is tilted downward and fixed to a connecting rod 75 located on one side of the vehicle body 71. The other end of the connecting rod 75 is hinged to a telescopic cylinder 76, which is hinged to the outer wall of the vehicle body 71 at the bottom. During the replacement process, the sodium storage vehicle 7 can simultaneously open the internal replacement, that is, the argon valve II 79 is opened, and the argon gas in the argon gas storage cylinder 77 is sent into the space between the kerosene surface and the cover plate 74 inside the vehicle body 71 through the argon gas pipe 78 to achieve inert gas protection and avoid the oxygen concentration in the protective chamber 1 from rising due to air brought in by the equipment. When sodium needs to be removed, the telescopic cylinder 76 retracts and opens the cover plate 74 through the connecting rod 75. The sodium removal robotic arm 8 clamps the sodium plate 73 in the kerosene. After standing for the kerosene to drip down, the telescopic cylinder 76 extends and closes the cover plate 74.

[0031] Example 4 This invention provides an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials, based on Example 1, such as... Figure 4 As shown, the preferred walking frame 81 is used for the sodium-removing robotic arm 8. The robotic arm 82 is fixed on the walking frame 81. The free end of the robotic arm 82 is fixed with a clamp 83, and the clamp 83 is equipped with a heating plate.

[0032] During the replacement process, when sodium needs to be removed, the walking frame 81 and the body 71 of the sodium storage vehicle 7 move closer to each other. After the cover 74 of the sodium storage vehicle 7 is opened, the robotic arm 82 drives the clamp 83 to pick up the sodium plate 73 from the kerosene in the sodium storage vehicle 7. After the kerosene drips down, the cover 74 of the sodium storage vehicle 7 is closed. The electric heating plate heats the clamp 83 to 100-150 degrees Celsius so that the sodium reacts with the oxygen and water vapor in the circulating gas.

[0033] Example 5 The present invention provides an anti-oxidation processing system for high-purity magnesium and magnesium alloy materials. Based on Example 4, a circulating fan 84 facing the clamp 83 is fixed on the walking frame 81, and multiple ultrasonic generators 22 are arranged longitudinally on the inner wall of the protective chamber 1.

[0034] During the replacement process, when sodium needs to be removed, the walking frame 81 and the body 71 of the sodium storage vehicle 7 move closer to each other. After the cover 74 of the sodium storage vehicle 7 is opened, the robotic arm 82 drives the clamp 83 to pick up the sodium plate 73 from the kerosene in the sodium storage vehicle 7. After the kerosene drips down, the cover 74 of the sodium storage vehicle 7 is closed. The electric heating plate heats the clamp 83 to 100-150 degrees Celsius. At the same time, the circulating fan 84 is started to start the circulation. The ultrasonic generator 22 is turned on simultaneously to assist the circulating fan 84 in promoting airflow, thereby promoting the reaction of metallic sodium with oxygen and water vapor in the circulating gas.

[0035] Example 6 This invention provides a method for controlling the oxidation-resistant processing environment of high-purity magnesium and magnesium alloy materials, comprising the following steps: Step 1: Pre-treat the air in protective chamber 1 to the target temperature and humidity: First, use a conventional household or industrial dehumidifier to reduce the humidity in protective chamber 1 to approximately 30%RH. The specific amount should be selected based on the ambient air parameters and the internal volume of the factory. The dehumidification principle is mechanical refrigeration below the air dew point, where water vapor condenses on the surface cooler. It is important to choose a dehumidifier with a water tank. Drainage pipes should not be installed inside protective chamber 1 to prevent water accumulation or leakage. Second, when the relative humidity drops below 60%RH, turn on the filter to filter 0.5–10μm dust particles. Excessive humidity will increase the surface resistance of the filter. Physical self-cleaning uses an FFU (high-efficiency particulate air filter with fan). The filtration performance can be selected according to the "High-Efficiency Air Filters" (GB / T 13554-2020). Generally, a high-efficiency filter is selected; for filtration of 99.999% or higher, an ultra-high-efficiency filter can be used. The rated airflow of the filter should be calculated based on the internal volume of the factory and the rated airflow of the high-efficiency filter, resulting in approximately 3 cycles per hour. In addition, the filter can also perform activated carbon adsorption during filtration. Finally, since subsequent replacement requires the calculation of air parameters, relatively certain temperature, relative humidity, and cleanliness are helpful in calculating replacement parameters. Moreover, the temperature rise after dehumidification causes the air volume to expand and the density to decrease, and the relative humidity to decrease, which is conducive to replacement. Therefore, except for winter operating conditions, the target temperature and humidity parameters before replacement are usually set to ≥30℃ and ≤30%RH.

[0036] Step 2: Open heat exchange valve 12 and start suction pump 10. Introduce air from protective chamber 1 into vaporizer 12 shell through heat exchange pipe I9. At the same time, open inlet valve 17, outlet valve 18 and argon valve I21, and close bypass valve 19. Introduce liquid argon from liquid argon storage tank 3 into vaporizer 12 inner tube through vaporization pipe I15 for primary vaporization. Primary vaporization absorbs heat to freeze and dehumidify the air inside vaporizer 12 shell. After freezing and dehumidification, the air returns to protective chamber 1 through heat exchange pipe II11. After liquid accumulates in vaporizer 12 shell, open drain valve 14 and discharge it through drain pipe 13. Gas-liquid two-phase argon or low-temperature argon in vaporizer 12 inner tube is introduced into vaporizer II4 through vaporization pipe II16 for secondary vaporization. The resulting fully vaporized argon is introduced into the bottom of protective chamber 1 through argon pipe 20 to replace the air upwards. The air above the argon is pushed out from the replacement exhaust port 6 at the top of protective chamber 1.

[0037] Step 3: During the replacement process, argon valve II 79 is opened, and argon gas from argon storage cylinder 77 is sent through argon pipe 78 into the space between the kerosene level and cover plate 74 inside vehicle body 71 to achieve inert gas protection. After argon concentration sensor 24 detects that the argon concentration reaches 97% or relative humidity sensor 24 detects that the relative humidity is ≤10%RH, the walking frame 81 and vehicle body 71 move closer to each other, and telescopic cylinder 76 retracts to open cover plate 74 through connecting rod 75. The robotic arm 82 drives clamp 83 to clamp sodium plate 73 from sodium plate support 72 in sodium storage vehicle 7. After standing for kerosene to drip down, telescopic cylinder 76 extends to close cover plate 74. The electric heating plate heats clamp 83 to 100-150℃, and at the same time, circulating fan 84 starts to start circulation. Ultrasonic generator 22 is turned on simultaneously to assist circulating fan 84 in promoting airflow, thereby promoting the reaction of metallic sodium with oxygen and water vapor in the circulating gas. During the reaction, if the hydrogen concentration sensor 23 detects that the hydrogen concentration has reached the alarm value, it will accelerate the argon supply, thereby discharging the hydrogen from the replacement exhaust port 6. The oxygen concentration sensor 24 and the relative humidity sensor 24 monitor the real-time oxygen and water vapor parameters. If the target value is not reached, the sodium can be taken out of the sodium storage vehicle 7 again by the sodium removal robotic arm 8, so that it reacts synchronously with the oxygen and water in the air in the protective chamber 1 to remove oxygen and water, until the oxygen and water vapor parameters reach the target value.

[0038] Step 4: After the replacement is completed and the humidity in the protective chamber 1 has dropped to an extremely low level, continuous deep dehumidification is no longer required. It is only necessary to maintain argon supply and positive pressure. At this time, close the inlet valve 17 and the outlet valve 18, open the bypass valve 19, and a small amount of liquid argon in the liquid argon storage tank 3 will directly enter the vaporizer II 4 through the bypass pipe 5 for vaporization, and then be sent into the protective chamber 1 through the argon pipe 20 to maintain positive pressure and prevent external air from entering the protective chamber 1.

[0039] The method for controlling the oxidation-resistant processing environment of high-purity magnesium and magnesium alloy materials provided by the present invention, through the above-described manner, has the following advantages: 1) It cleverly utilizes the heat absorption characteristics of argon gas during liquid vaporization to achieve deep dehumidification without consuming energy.

[0040] 2) Deep dehumidification reduces the volumetric mass during gas replacement, thus improving efficiency compared to dilution by water vapor replacement.

[0041] 3) Highly active sodium metal is used to oxidize and eliminate trace amounts of oxygen that are difficult to remove by displacement.

Claims

1. A high-purity magnesium and magnesium alloy anti-oxidation processing system, characterized in that, The protective chamber (1) is connected to a shell-and-tube vaporizer I (2) via a heat exchange pipe on one side of the protective chamber (1). The inlet end of the inner tube of vaporizer I (2) is connected to a liquid argon storage tank (3). The outlet end of the inner tube of vaporizer I (2) is connected to vaporizer II (4). The inlet and outlet ends of the inner tube of vaporizer I (2) are connected in parallel to a bypass pipe (5). The outlet end of vaporizer II (4) is connected to the bottom of the protective chamber (1) via a pipe. A replacement exhaust port (6) is opened at the top of the protective chamber (1). A sodium storage vehicle (7) and a corresponding sodium-retrieving robotic arm (8) are installed inside the protective chamber (1).

2. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 1, characterized in that, The inlet end of the outer shell of the vaporizer I (2) is connected to the protective chamber (1) through heat exchange pipe I (9). A suction pump (10) is connected to heat exchange pipe I (9). The outlet end of the outer shell of the vaporizer I (2) is connected to the protective chamber (1) through heat exchange pipe II (11). Heat exchange valves (12) are provided on both heat exchange pipe I (9) and heat exchange pipe II (11). A drain pipe (13) is connected to the bottom of the outer shell of the vaporizer I (2). A drain valve (14) is provided on the drain pipe (13).

3. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 1, characterized in that, The inlet end of the inner tube of the vaporizer I (2) is connected to the liquid argon storage tank (3) through the vaporization pipe I (15). The outlet end of the inner tube of the vaporizer I (2) is connected to the vaporizer II (4) through the vaporization pipe II (16). The two ends of the bypass pipe (5) are connected in parallel to the vaporization pipe I (15) and the vaporization pipe II (16) respectively. The section of the vaporization pipe I (15) connected in parallel with the bypass pipe (5) is equipped with an inlet valve (17). The section of the vaporization pipe II (16) connected in parallel with the bypass pipe (5) is equipped with an outlet valve (18). The bypass pipe (5) is equipped with a bypass valve (19). The outlet end of the vaporizer II (4) is connected to the bottom of the protective chamber (1) through the argon pipe (20). The argon pipe (20) is equipped with an argon valve I (21).

4. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 1, characterized in that, The sodium storage vehicle (7) includes a box-shaped vehicle body (71) with an opening at the top. The vehicle body (71) is filled with kerosene. A sodium plate support (72) is provided at the bottom of the vehicle body (71). A louvered sodium plate (73) is placed on the sodium plate support (72) below the kerosene level.

5. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 4, characterized in that, The top side of the vehicle body (71) is hinged to a cover plate (74) located above the opening. The hinge position of the cover plate (74) is inclined downward and fixed to a connecting rod (75) located on one side of the vehicle body (71). The other end of the connecting rod (75) is hinged to a telescopic cylinder (76) that is hinged to the bottom of the vehicle body (71) and connected to the outer wall of the vehicle body (71).

6. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 4 or 5, characterized in that, An argon gas storage cylinder (77) is fixed on the outer wall of the vehicle body (71). An argon gas pipe (78) extending to the kerosene level inside the vehicle body (71) is connected to the argon gas storage cylinder (77). An argon gas valve II (79) is installed on the argon gas pipe (78).

7. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 1, characterized in that, The sodium-removing robotic arm (8) includes a walking frame (81), on which a robotic arm (82) is fixed. A clamp (83) is fixed to the free end of the robotic arm (82), and an electric heating plate is provided on the clamp (83).

8. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 7, characterized in that, The walking frame (81) is fixed with a circulating fan (84) facing the clamp (83), and multiple ultrasonic generators (22) are arranged longitudinally on the inner wall of the protective chamber (1).

9. The anti-oxidation processing system for high-purity magnesium and magnesium alloy materials as described in claim 1, characterized in that, A hydrogen concentration sensor (23) is installed at the top of the protective chamber (1), and an argon concentration sensor (24), an oxygen concentration sensor (24) and a relative humidity sensor (24) are arranged on the inner wall of the protective chamber (1).

10. A method for controlling the anti-oxidation processing environment of high-purity magnesium and magnesium alloy materials based on the system described in claim 1, characterized in that, include: Step 1: Pre-treat the air inside the protective chamber to the target temperature and humidity; Step 2: The air in the protective chamber is introduced into the outer shell of vaporizer I, and liquid argon is introduced into the inner tube of vaporizer I for primary vaporization. The vaporization absorbs heat and freezes and dehumidifies the air in the outer shell. The argon in the inner tube is then introduced into vaporizer II for secondary vaporization. The resulting argon is introduced into the protective chamber to replace the air. Step 3: The sodium removal robotic arm takes out the metallic sodium from the sodium storage vehicle and brings it into contact with the air in the protective chamber. The sodium reacts with oxygen and water in the air to remove oxygen and water. Step 4: After switching the liquid argon to the bypass pipeline, it is introduced into vaporizer II for vaporization. The resulting argon gas is then introduced into the protective chamber to replenish gas and maintain positive pressure.

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