Main reactor structure with annular cavity shielding gas

Abstract

The invention discloses a main reactor structure with annular cavity shielding gas, and relates to the technical field of plasma chemical equipment, in particular to the main reactor structure with the annular cavity shielding gas, which comprises a high-temperature plasma source and a cylindrical annular main reactor with a partition plate of a double-layer water-cooling interlayer, and the tail end of the main reactor is of a double-layer inverted conical structure. The annular cavity shielding gas inlet is located at the upper end of the main reactor, is flush with the plasma source outlet and is in tangential connection with the plasma source outlet, and the included angle between the axis and the horizontal plane is 55-75 degrees. According to the structure, by controlling parameters such as the pipe diameter proportion of an annular cavity shielding gas inlet, the flow of introduced gas and the temperature, and combining with a high-temperature plasma source for independently supplying gas, efficient treatment of graphite powder is realized, inner wall overheating and product oxidation are prevented, and the reaction stability and the product quality are improved.

Description

Technical Field

[0001] This invention relates to the field of plasma chemical equipment technology, specifically to a main reactor structure with an annular protective gas chamber. Background Technology

[0002] Plasma technology, due to its ability to provide a high-temperature, high-energy-density reaction environment, has wide applications in materials synthesis, powder spheroidization, and surface treatment. In the deep processing of graphite powder, the high temperatures generated by a plasma torch are often used to melt and spheroidize the graphite powder, improving its sphericity, flowability, and chemical purity to meet the application requirements of high-end lithium-ion battery anodes and thermal conductive materials. However, existing plasma reactors still face a series of technical bottlenecks in graphite powder processing, hindering further improvements in spheroidization efficiency and product quality.

[0003] Currently, most plasma reactors used for powder spheroidization employ a vertical structure, with a high-temperature plasma torch located at the top. Graphite powder is carried into the plasma stream by a carrier gas, melts into spheres under high temperature, and is then cooled and collected in the lower section of the reactor. However, this process has significant problems: the molten graphite microspheres are prone to impacting the reactor's inner wall under the influence of high-speed airflow, leading to sphere deformation, adhesion, or breakage. This not only reduces the spheroidization rate but also causes powder accumulation on the wall surface, affecting the stability of continuous operation. For example, patent CN105840315B discloses a swirling cooling gas chamber structure that reduces the wall temperature through swirling cooling gas, but its airflow organization makes it difficult to completely avoid wall contact between molten particles, especially for high-viscosity, easily agglomerated graphite materials, where the effect is limited. Patent CN109743832B proposes a composite cooling device, focusing on the cooling and lifespan improvement of the plasma torch itself, without optimizing the powder movement behavior within the reactor. Patent CN212883010U involves improvements to the hydrocyclone structure. While it emphasizes wear resistance and ease of replacement, it does not solve the problem of powder motion control in the high-temperature range.

[0004] A common drawback of existing technologies is the lack of precise control over the gas-solid two-phase flow within the reactor. Specifically, there is a lack of an effective transition barrier between the high-temperature and cooling zones within the reactor, allowing molten particles to still impact the reactor walls due to inertia. Furthermore, the airflow within the reactor is mostly axial or simple swirling, making it difficult to form a uniform and stable gas film isolation layer. In addition, electrostatic effects easily lead to the agglomeration and accumulation of fine powders in localized areas, further reducing powder recovery rate and product consistency. Summary of the Invention

[0005] The purpose of this invention is to provide a main reactor structure with an annular protective gas. By setting an annular protective gas inlet at the upper end of the main reactor that is tangentially connected to the main reactor and whose angle and pipe diameter ratio are adapted, and in conjunction with a double-layer water-cooled jacket and specific structural parameters, the oxidation problem of graphite powder reaction under high-temperature plasma environment is solved, thereby improving the purity and stability of the product.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a main reactor structure with an annular protective gas, comprising a high-temperature plasma source installed at the upper end of the main reactor to generate a high-temperature plasma flow field to introduce graphite powder and place it in a high-temperature reaction environment; the graphite powder is carried into the main reactor with a double-layer water-cooled jacket by the plasma jet formed by the high-temperature plasma source, the double-layer water-cooled jacket surrounding the outer periphery of the main reactor body, which can continuously cool the main reactor wall during the reaction to avoid overheating; the main reactor is cylindrical and annular in shape, and is internally provided with several radial or axial baffles to form partitioned areas, which can guide the airflow and powder. The reactor exhibits a more uniform volume distribution and enhanced ability to control reaction residence time. The tail end of the main reactor is designed with a double-layered inverted conical structure, with cooling water flowing between the two layers to form a cooling loop, which can enhance the cooling effect on the high-temperature area at the end. An annular protective gas inlet is also provided, located at the upper end of the main reactor and at the same level as the plasma source outlet, so that the protective gas can form a surrounding gas curtain around the plasma jet. The middle part of the main reactor chamber is connected to a cyclone separator through a connecting pipe with branch pipes, which uses gas-solid separation to capture product particles. The bottom inverted conical tip serves as a powder outlet, which is connected to the collection chamber through a controllable valve, facilitating the directional discharge and collection of powder after reaction.

[0007] Furthermore, the annular protective gas inlet is tangentially connected to the main reactor chamber, allowing the protective gas to enter along the tangential direction of the inner wall of the main reactor. This creates a rotating airflow at the inlet, promoting uniform gas distribution within the annular cavity and allowing the gas to flow closely against the wall, thereby forming a continuous and stable gas film protective layer.

[0008] Furthermore, the angle between the axis of the protective gas inlet of the annular cavity and the horizontal plane is 55°~75°. This angle range allows the protective gas to have both a downward momentum component and a surrounding tangential component when entering the main reactor, which is conducive to forming a uniformly covered gas curtain with a certain scouring force in the annular cavity, thereby improving the heat insulation and anti-corrosion effect on the high-temperature wall surface.

[0009] Furthermore, the ratio of the diameter of the protective gas inlet pipe in the annular cavity to the diameter of the main reactor is in the range of 0.06 to 0.08. Under this ratio, the flow rate of the protective gas can be matched with the flow cross section of the reactor, so that an effective gas film can be formed in the annular cavity without weakening the protective effect due to too low a flow rate or causing unnecessary kinetic energy loss and turbulence disturbance due to too high a flow rate.

[0010] Furthermore, the ratio of the inlet diameter of the annular protective gas to the branch pipe diameter of the connecting pipeline is in the range of 0.2 to 0.5. This ratio can coordinate the flow distribution relationship between the protective gas entering the main reactor and the subsequent gas-solid mixture entering the cyclone separator, so that the flow resistance of the annular protective gas matches the conveying capacity of the branch pipe, and maintain the stability and continuity of the overall flow field.

[0011] Furthermore, the working gas flow rate of the high-temperature plasma source is in the range of 140~186 slm. This flow rate range can form a high-temperature plasma with suitable energy density and jet length, so that the graphite powder can be fully melted or vaporized in the effective heating zone, while avoiding insufficient temperature in the reaction zone due to too low a flow rate or energy dispersion due to too high a flow rate.

[0012] Furthermore, the angle α between the inverted conical structure at the tail end of the main reactor and the horizontal plane is 120°~135°. Within this angle range, the falling powder and airflow can be smoothly turned at the conical surface and concentrated towards the outlet, reducing the adhesion and accumulation of powder on the wall surface, while facilitating the smooth discharge of the gas-solid two-phase flow.

[0013] Furthermore, the gas flow rate introduced into the annular protective gas inlet is in the range of 1300~1700 slm. This flow rate range can form a gas film of sufficient thickness and velocity in the annular cavity of the main reactor, effectively isolating the high-temperature reaction zone from the reactor wall, and taking into account both cooling requirements and gas flow dynamic balance.

[0014] Furthermore, the inert gas introduced into the annular cavity protective gas inlet has a temperature of 5~15℃. The lower temperature inert gas can rapidly absorb heat and expand after entering the high temperature annular cavity, forming a stable low temperature gas curtain, which helps to reduce the wall heat load and improve the coverage stability of the protective gas.

[0015] Furthermore, the gas source of the annular protective gas inlet and the working gas of the high-temperature plasma source are supplied independently, and the type, flow rate and temperature parameters of the two gases can be adjusted separately, so that the plasma jet characteristics and the protective gas film characteristics do not interfere with each other, and the independent optimized control of reaction zone heating and wall protection is achieved.

[0016] This invention provides a main reactor structure with an annular protective gas chamber, which has the following beneficial effects: 1. This structure introduces a low-temperature inert gas to form a surrounding protective airflow, constructing a stable gas curtain barrier around the reaction zone. This effectively blocks the intrusion of external impurities and suppresses the disorderly diffusion of heat in the high-temperature zone. The gas is injected at a specific angle and flow rate, working synergistically with the plasma plume to make the temperature field distribution in the core reaction zone more uniform, reducing powder melting and agglomeration caused by local overheating, and improving the uniformity of product particle size. Simultaneously, the dynamic gas film formed by the protective gas buffers the thermal stress on the reactor inner wall, and the double-layer water-cooling structure extends the equipment's lifespan. Furthermore, the independent gas source design avoids mutual interference between working gases, ensuring process stability.

[0017] The tangential connection and specific angled airflow introduction method create a spiral downward flow of protective gas along the inner wall of the reactor, enhancing the heat exchange efficiency between the gas and the reactor wall, quickly removing residual heat from the side walls, and preventing material sintering caused by localized high temperatures. This swirling effect also drives gaseous products to converge towards the center, shortening their residence time in the high-temperature zone and reducing side reactions; at the same time, it enhances the relative motion rate between the gas and solid phases, promoting full contact between unreacted raw materials and plasma, improving raw material conversion efficiency, and reducing energy consumption.

[0018] The cryogenic characteristics of the annular protective gas, combined with precise flow control, create a robust thermal management system: Upon injection, the cryogenic gas rapidly absorbs heat from the upper and sidewalls of the reactor, reducing the overall heat load and sparing the cooling water system from excessive temperature differential impact, thus minimizing thermal fatigue damage. Simultaneously, the controlled flow rate ensures sufficient gas curtain thickness to isolate the air while preventing excessive dilution of the plasma energy density, maintaining the high-temperature intensity of the core region. This design allows for efficient reactor operation while maintaining gentler and more controllable thermal management, enhancing the reliability of continuous operation.

[0019] The synergistic design of the inverted conical tail end and the branch pipe connection structure utilizes the dual effects of gas swirling and gravity to achieve gradient separation of powder: the high-speed swirling flow throws coarse particles against the container wall and guides them to the bottom of the cone, while fine particles enter the branch pipe with the airflow. The constricted design at the bottom tip further accelerates particle settling and reduces fine powder entrainment; the symmetrical distribution of the branch pipes balances the air velocity in each path, avoiding localized blockages. This structure allows the powder to be discharged in an orderly manner according to particle size, simplifying subsequent classification processes, improving collection efficiency, and reducing the disturbance of reaction equilibrium caused by airflow backmixing, thus ensuring batch-to-batch product consistency.

[0020] The independent gas supply system and parameter matching optimization provide flexible process control: the annular protective gas and working gas are controlled separately, and their ratio can be adjusted according to the characteristics of the raw materials or the target product—for example, increasing the protective gas flow rate when processing easily oxidizable materials, and fine-tuning the working gas flow rate to maintain the plasma temperature when processing high-melting-point materials. Multi-parameter linkage design (pipe diameter ratio, tilt angle, temperature, etc.) forms a standardized control model, allowing operators to quickly adapt to different operating conditions, shortening the process debugging cycle, and improving production efficiency and product adaptability. Attached Figure Description

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0022] Figure 1 This is a structural diagram of the main reactor with an annular protective gas according to the present invention; Figure 2 This is a schematic diagram of the inlet and horizontal inclination angle of the present invention; Figure 3 This is a streamline diagram of the protective gas in the annular cavity of the present invention.

[0023] Part Name: 1. Annular protective gas inlet; 2. High-temperature plasma source; 3. Main reactor; 4. Connecting pipeline; 5. Inverted conical tip. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] How to use: 1. Preparation stage: Confirm that the gas supply system of the annular protective gas inlet 1 and the working gas of the high-temperature plasma source 2 are ready, and check that the gas supply passages of the two are unobstructed; prepare the graphite powder, and ensure that the cooling water circulation in the double-layer water-cooled jacket of the main reactor 3 and the double-layer partition of the double-layer inverted conical structure at the tail end is normal, and that the valve between the bottom inverted conical tip 5 and the receiving chamber is closed.

[0027] Start the annular protective gas: Open the annular protective gas inlet 1 and introduce inert gas at a temperature of 5~15℃, controlling the gas flow rate within the range of 1300~1700 slm; Note that the annular protective gas inlet 1 and the main reactor 3 chamber are connected tangentially (claim 2), and the angle between its axis and the horizontal plane is maintained at 55°~75° (claim 3), the ratio of pipe diameter d1 to the diameter D of the main reactor 3 is 0.06~0.08 (claim 4), and the ratio of pipe diameter d1 to the diameter d2 of the branch pipe of the connecting pipe 4 is 0.2~0.5 (claim 5), so that the protective gas forms a stable gas flow layer around the inner wall of the main reactor 3 tangentially, isolating the high temperature environment from erosion of the reactor wall.

[0028] Operating the high-temperature plasma source: After the protective gas in the annular cavity stabilizes, start the high-temperature plasma source 2, introduce the working gas and control the flow rate within the range of 140~186 slm to generate high-temperature plasma; the graphite powder enters the main reactor 3 with a double-layer water-cooled jacket through the high-temperature plasma source 2, and the high temperature of the plasma causes the graphite powder to undergo the target reaction.

[0029] Controlling the operating conditions of the main reactor: The main reactor 3 is a cylindrical annular structure with baffles, and the tail end is a double-layer inverted conical structure (claim 1). The angle α between the conical surface and the horizontal plane is maintained at 120°~135° (claim 7) to ensure that the material flows smoothly to the bottom after the reaction. The middle part of the main reactor 3 chamber is connected to the cyclone separator through the connecting pipe 4 with branch pipes (claim 1). The products generated by the reaction enter the cyclone separator for separation with the airflow through the connecting pipe 4. The unreacted light components can be recycled.

[0030] Product collection: During the reaction, the powder after reaction and separation is finally collected at the bottom inverted conical tip 5 of the main reactor 3 (claim 1). When the reaction is over or the preset discharge conditions are met, the valve between the bottom inverted conical tip 5 and the collection chamber is opened to discharge the powder from the powder outlet and collect it into the collection chamber.

[0031] Shutdown and Maintenance: After use, first stop the supply of working gas to the high-temperature plasma source 2. After the temperature inside the main reactor 3 drops to a safe range, gradually reduce the gas flow rate at the annular protective gas inlet 1 until it is shut off. After checking that there are no abnormalities in the cooling water system inside the double-layer water-cooled jacket and double-layer partition, the operation process is complete. Throughout the process, it is necessary to ensure that the gas source at the annular protective gas inlet 1 and the working gas of the high-temperature plasma source 2 are always supplied independently (claim 10) to maintain the stability of their respective process parameters.

[0032] Example: Example 1 This embodiment demonstrates the application of a main reactor structure with an annular protective gas in a real-world scenario. First, preparatory operations are performed, confirming that the independent gas supply systems for the annular protective gas inlet 1 and the high-temperature plasma source 2 are both operational, and verifying that their supply paths are free from blockages or leaks. The graphite powder to be processed is prepared, and the cooling water circulation of the double-layer water-cooled jacket and the double-layer partition within the double-layer inverted conical structure at the tail end of the main reactor 3 is initiated to ensure continuous and stable cooling. Simultaneously, the valve between the bottom inverted conical tip 5 and the receiving chamber is checked to ensure it is reliably closed, preventing premature material leakage.

[0033] Next, the annular protective gas is activated. Low-temperature inert gas is introduced through the annular protective gas inlet 1. The gas is tangentially connected to the main reactor 3 chamber at the inlet, with its axis at a suitable angle relative to the horizontal plane. The inlet pipe diameter is proportional to the diameter of the main reactor 3 and also matches the diameter of the branch pipe in the connecting pipe 4. This causes the protective gas to form a uniform, surrounding gas flow layer along the inner wall of the main reactor 3, effectively isolating the direct heat effect on the reactor wall in the subsequent high-temperature environment. At this point, the flow pattern of the protective gas is stable, establishing a safety boundary for the subsequent high-temperature reaction.

[0034] Subsequently, high-temperature plasma source 2 is activated, introducing working gas and creating a high-temperature plasma environment. Graphite powder enters the main reactor 3 through this plasma source. The main reactor 3 has a cylindrical annular structure with baffles, combined with a double-layer inverted conical structure at the tail end. Its cone angle is rationally designed to facilitate the natural convergence of reactants to the bottom by gravity. The high temperature of the plasma acts on the graphite powder, initiating the predetermined reaction process. The mixed gas flow generated by the reaction carries the products into the central branch pipe 4, which is then guided to a cyclone separator for gas-solid separation. The heavier powder remains in the system, while the lighter components are recycled as needed.

[0035] When the reaction reaches the expected progress or when product collection is required, open the valve between the bottom inverted conical tip 5 and the receiving chamber. The powder will smoothly discharge from the powder outlet and be collected into the receiving chamber. After use, sequentially stop the working gas input of the high-temperature plasma source 2. After the main reactor 3 has cooled down to a safe range, gradually reduce and close the gas supply to the annular protective gas inlet 1. During this period, maintain the cooling water in the double-layer water-cooled jacket and double-layer partition until the equipment is completely cooled. Throughout the process, the annular protective gas inlet 1 and the high-temperature plasma source 2 maintain independent gas supply and do not interfere with each other, ensuring stable and reliable process parameters.

[0036] Example 2 This main reactor structure is applied in the preparation of a special material. During the preparation stage, the independent gas supply circuits of the annular protective gas inlet 1 and the high-temperature plasma source 2 need to be fully inspected to confirm that the gas source switching and control device are sensitive and accurate. Graphite powder is placed into the feeding stage according to the process requirements. The cooling medium circulation of the double-layer water-cooled jacket of the main reactor 3 is started first, and the cooling channels of the double-layer partition in the double-layer inverted conical structure at the tail end are checked to ensure that the valve is closed between the bottom inverted conical tip 5 and the receiving chamber to prevent accidental discharge.

[0037] Initially, the annular protective gas inlet 1 is activated, using a low-temperature inert gas as the protective medium. Its introduction direction is tangentially connected to the main reactor 3 chamber, with the axis tilt angle matching the design. The inlet pipe diameter is appropriately proportioned to the main reactor 3 diameter and also matches the diameter of the branch pipe in connecting pipeline 4, thus forming a stable, wall-mounted gas curtain that constructs a thermal insulation barrier on the inner wall of the main reactor 3. This gas curtain effectively mitigates thermal shock and extends the structural lifespan during subsequent high-temperature stages.

[0038] The high-temperature plasma source 2 is then activated, converting the working gas into high-temperature plasma. Graphite powder enters the main reactor 3 under the influence of this plasma source. The main reactor 3 features a cylindrical annular baffled layout combined with a double-layered inverted conical structure at the tail end, the angle of which facilitates the flow of reactants to the bottom. The plasma energy causes the graphite powder to undergo a predetermined transformation. The generated products are carried by the gas flow through a connecting pipe 4 with branch pipes into a cyclone separator, achieving efficient gas-solid separation. The solid products remain within the system, while the gaseous byproducts can be processed separately or recovered.

[0039] After the operation is completed, open the valve between the bottom inverted conical tip 5 and the receiving chamber, and the powder will be discharged from the powder outlet into the receiving chamber. After receiving, sequentially shut off the working gas of the high-temperature plasma source 2, monitor the temperature drop of the main reactor 3, and gradually stop the gas supply to the annular protective gas inlet 1 after the temperature drop is sufficient, while maintaining the cooling process inside the double-layer water-cooled jacket and double-layer partitions until the entire equipment is cooled down. Throughout the process, the annular protective gas inlet 1 and the high-temperature plasma source 2 gas supply system are not connected to each other, and their parameters are independently controllable to ensure process consistency.

[0040] Example 3 When applied to continuous powder modification operations, this main reactor structure is used for operation. During preparation, verify the independent gas supply configuration of the annular protective gas inlet 1 and the high-temperature plasma source 2 to ensure that the two gas sources can be opened and closed as needed without cross-contamination; continuously transport graphite powder to the inlet of the high-temperature plasma source 2, activate the cooling function of the double-layer water-cooled jacket and the double-layer baffle structure of the tail end of the main reactor 3, and check that the valve between the bottom inverted conical tip 5 and the receiving chamber is airtight to avoid leakage during operation.

[0041] The first step involves opening the annular protective gas inlet 1 and injecting low-temperature inert gas. The gas enters the main reactor 3 chamber tangentially, with an appropriate axial tilt angle. The inlet pipe diameter is proportionate to the main reactor 3 diameter and appropriately proportionate to the branch pipe diameter of the connecting pipe 4, forming a uniformly surrounding protective gas layer. This provides stable boundary conditions for subsequent high-temperature reactions. This gas layer effectively reduces heat transfer back to the reactor wall, maintaining structural integrity.

[0042] The second step involves activating the high-temperature plasma source 2, introducing working gas to excite the high-temperature plasma, through which the graphite powder enters the main reactor 3. The main reactor 3 is a cylindrical annular structure with baffles, and its tail end is a double-layered inverted conical structure with an optimized cone angle to facilitate material sliding to the bottom. The high temperature of the plasma drives the graphite powder modification reaction, and the reaction mixture is sent to a cyclone separator via a connecting pipe 4 with branch pipes, separating the modified powder from the waste gas. The waste gas can be further purified or reused.

[0043] During continuous operation, the valve between the bottom inverted conical tip 5 and the receiving chamber is opened periodically to collect the modified powder into the receiving chamber, maintaining continuous production. When shutting down, first stop the working gas of the high-temperature plasma source 2. After the main reactor 3 cools to a safe value, gradually reduce and close the gas supply to the annular protective gas inlet 1. Cooling within the double-layer water-cooled jacket and double-layer partition continues until the equipment is fully cooled. The annular protective gas inlet 1 and the high-temperature plasma source 2 maintain independent gas supply throughout the entire operating cycle to avoid mutual interference.

[0044] Example 4 This main reactor structure was used in a high-purity powder synthesis task. During the preparation stage, it was important to confirm that the gas supply systems of the annular protective gas inlet 1 and the high-temperature plasma source 2 were independent of each other, that the gas supply paths were clean and there was no risk of cross-contamination; the high-purity graphite powder was properly loaded into the feeding unit, and the double-layer water-cooled jacket and the double-layer baffle cooling system of the tail end double-layer inverted conical structure of the main reactor 3 were operated first to verify that the sealing performance of the valve between the bottom inverted conical tip 5 and the receiving chamber met the standards.

[0045] First, activate the annular protective gas inlet 1 and input low-temperature inert gas. It enters the main reactor 3 chamber through a tangential connection with an axis tilt angle that fits the design. The inlet pipe diameter is in a suitable ratio to the diameter of the main reactor 3 and matches the diameter ratio of the branch pipe of the connecting pipe 4. This generates a wall-mounted rotating protective gas field, which can prevent external impurities from entering and reduce the heat load on the reactor wall during the high-temperature stage.

[0046] The high-temperature plasma source 2 is then restarted, and the working gas is excited into high-temperature plasma, through which the graphite powder enters the main reactor 3. The cylindrical annular structure with baffles in the main reactor 3 works synergistically with the double-layer inverted conical structure at the tail end, and the cone angle design facilitates the concentration of reaction products to the bottom. The plasma conditions promote the conversion of graphite powder into high-purity products, and the reaction gas-solid mixture enters the cyclone separator through the connecting pipe 4 with branch pipes, achieving efficient separation, and the pure powder remains in the system.

[0047] During the collection phase, the valves at the bottom inverted conical tip 5 and the receiving chamber are opened, allowing high-purity powder to enter the receiving chamber from the powder outlet. At the end of the operation, the working gas supply to the high-temperature plasma source 2 is first stopped. Once the temperature of the main reactor 3 returns to a safe level, the gas supply to the annular protective gas inlet 1 is gradually stopped. Cooling within the double-layer water-cooled jacket and double-layer partitions continues until the entire equipment is cooled. Throughout the process, the annular protective gas inlet 1 and the high-temperature plasma source 2 are supplied with gas independently to ensure synthesis purity and process stability.

[0048] Example 5 When used for intermittent experimental research, the main reactor structure can be used as follows. During preparation, check the independent gas supply circuits of the annular protective gas inlet 1 and the high-temperature plasma source 2 to ensure that they can be flexibly switched between different batches of the experiment without affecting each other; weigh the graphite powder for the experiment quantitatively and place it in the feeding position; start the cooling function of the double-layer water-cooled jacket and the double-layer inverted conical structure at the tail end of the main reactor 3; pre-close the valve between the bottom inverted conical tip 5 and the receiving chamber to prevent the experimental material from leaking out.

[0049] When the test is started, the protective gas inlet 1 of the annular cavity is opened first, and low-temperature inert gas is introduced. The gas enters the main reactor 3 chamber in a tangential manner. The axial tilt angle is consistent with the design requirements. The diameter of the inlet pipe is coordinated with the diameter of the main reactor 3 and matched with the diameter of the branch pipe of the connecting pipe 4, forming a uniformly surrounding protective gas layer, which provides reliable thermal insulation protection for short-term high-temperature tests.

[0050] Subsequently, high-temperature plasma source 2 is activated, and the working gas is converted into high-temperature plasma. Graphite powder enters the main reactor 3 and reacts under the action of plasma. The cylindrical annular structure with baffles in the main reactor 3, combined with the double-layer inverted conical structure at the tail end, has a cone angle that facilitates product settling to the bottom. The mixture formed by the reaction flows through the connecting pipe 4 with branch pipes into the cyclone separator, where the target product and residual gas are separated.

[0051] At the end of each batch of experiments, the valve between the bottom inverted conical tip 5 and the collection chamber is opened to collect the obtained powder into the collection chamber for analysis. When shutting down, the working gas of the high-temperature plasma source 2 is stopped first. After the main reactor 3 cools to a safe range, the gas supply to the annular protective gas inlet 1 is gradually closed. Cooling within the double-layer water-cooled jacket and double-layer partition continues until the equipment is completely cooled. Throughout the experiment, the annular protective gas inlet 1 and the high-temperature plasma source 2 maintain independent gas supply to ensure that the experimental conditions for different batches can be accurately reproduced.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A main reactor structure with an annular protective gas chamber, characterized in that: The system includes a high-temperature plasma source (2) installed at the top of the main reactor (3). Graphite powder enters the main reactor (3) with a double-layer water-cooled jacket through the high-temperature plasma source. The main reactor (3) is a cylindrical annular structure with a partition, and the tail end is a double-layer inverted conical structure. Cooling water is circulated inside the double-layer partition for cooling. The annular protective gas inlet (1) is located at the top of the main reactor (3) and is flush with the outlet of the plasma source (2). The middle part of the main reactor (3) is connected to the cyclone separator by a connecting pipe (4) with a branch pipe. The inverted conical tip (5) at the bottom is the powder outlet and is connected to the recovery chamber through a valve.

2. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The annular protective gas inlet (1) is tangentially connected to the main reactor (3) chamber.

3. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The axis of the annular protective gas inlet (1) has an angle of 55°~75° with the horizontal plane.

4. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The ratio of the diameter d1 of the annular protective gas inlet (1) to the diameter D of the main reactor (3) is in the range of 0.06~0.

08.

5. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The ratio of the diameter d1 of the annular protective gas inlet (1) to the diameter d2 of the branch pipe of the connecting pipe (4) is 0.2 to 0.

5.

6. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The working gas flow rate of the high-temperature plasma source (2) is 140~186 slm.

7. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The angle α between the inverted conical structure at the tail end of the main reactor (3) and the horizontal plane is 120°~135°.

8. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The gas flow rate introduced into the annular cavity protective gas inlet (1) is in the range of 1300~1700 slm.

9. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The temperature of the inert gas introduced into the annular protective gas inlet (1) is 5~15℃.

10. The main reactor structure with an annular protective gas according to claim 1, characterized in that... The gas source of the annular protective gas inlet (1) and the working gas of the high-temperature plasma source (2) are supplied independently to each other.

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