An ultrahigh temperature plasma spheroidization apparatus

Abstract

The application discloses an ultrahigh-temperature plasma spheroidization equipment and belongs to the technical field of spheroidization equipment. The ultrahigh-temperature plasma spheroidization equipment comprises a plasma assembly, a main reactor and the like. The plasma assembly comprises a plasma cabinet, a power line and a gas flow control unit and is used for generating a high-temperature plasma jet. The main reactor is a double-layer stainless steel water-cooling structure, and the top of the main reactor is communicated with the outlet of the plasma cabinet. In the application, through the cooperation of the plasma torch and the multi-stage grading cooling structure, the continuous and integrated production from irregular raw material powder to high-purity spherical powder is realized, the sphericity and the fine powder yield are significantly improved, the particles are sequentially captured by the main reactor, the cyclone separator and the auxiliary reactor, the pulse back-blowing dust removal in the auxiliary reactor and the non-stop discharging design are combined, the tail gas purification and the powder efficient recovery are ensured, and the equipment operation continuity and the production efficiency are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of spheroidizing equipment technology, specifically an ultra-high temperature plasma spheroidizing device. Background Technology

[0002] Ultra-high temperature plasma spheroidization technology utilizes a thermal plasma jet (typically a DC arc or radio frequency inductively coupled plasma, with temperatures reaching thousands to tens of thousands of degrees Celsius) to rapidly heat and melt irregularly shaped raw material powders such as metals, ceramics, or alloys. This causes the particles to shrink into spherical droplets under surface tension, which are then cooled and solidified to obtain spherical powders with high sphericity, high fluidity, and high tap density. This technology is a key upstream process in additive manufacturing (3D printing), powder metallurgy, thermal spraying, electronic packaging, and high-performance composite materials. The quality of its products directly affects the density, mechanical properties, and service life of downstream components. Compared to traditional spheroidization processes such as atomization and mechanical grinding, plasma spheroidization offers significant advantages, including concentrated heat source, high temperature, no electrode contamination, and controllable atmosphere. It is particularly suitable for the precision spheroidization modification of high-value-added powders such as titanium alloys, nickel-based superalloys, tungsten-molybdenum refractory metals, and oxide ceramics.

[0003] However, existing ultra-high temperature plasma spheroidizing equipment still faces many technical bottlenecks in industrial continuous production. Firstly, most equipment adopts a single-stage reaction and separation structure, resulting in a short cooling path and uneven cooling rate for the powder after high-temperature melting, leading to low fine powder yield. A large amount of fine spherical powder escapes with the exhaust gas, causing not only material waste but also dust pollution. Secondly, the reactor and pipelines are subjected to the thermal shock of the ultra-high temperature plasma jet for extended periods, lacking efficient and uniform cooling protection design. This makes the walls prone to high-temperature deformation, ablation, and spalling, severely affecting equipment lifespan and process stability. Thirdly, the feeding system commonly suffers from powder agglomeration due to moisture, bridging, and blockage, resulting in large fluctuations in the feeding rate. Fourth, the dust layer on the surface of filter bags in exhaust gas purification equipment such as baghouse dust collectors gradually thickens during continuous operation, requiring shutdown for cleaning and interruption of production for collection tank replacement, significantly reducing equipment utilization and production efficiency. Fifth, the entire system has strict oxygen content control, but existing equipment is prone to air mixing in during powder collection, sampling, and packaging, causing oxidation and deterioration of high-temperature spherical powder. Furthermore, the lack of intelligent linkage control for various process parameters (air supply pressure, system vacuum, cooling water temperature, etc.) makes it difficult to meet the stringent requirements of high-end powders for batch stability and traceability. Therefore, developing an ultra-high temperature plasma spheroidizing device that integrates efficient melting spheroidization, staged cooling and collection, continuous discharge and cleaning, inert atmosphere fully enclosed collection, and intelligent control is a technical challenge that needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-high temperature plasma spheroidizing device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an ultra-high temperature plasma spheroidizing device, comprising: A plasma assembly, comprising a plasma cabinet, a power cord, and a gas flow control unit, for generating a high-temperature plasma jet; The main reactor is a double-layer stainless steel water-cooled structure. Its top is connected to the outlet of the plasma cabinet. It is used to receive the spherical powder formed after being heated and melted by the high-temperature plasma jet, and to perform preliminary cooling and solidification of the spherical powder through jacket cooling water. A primary cyclone separator is connected to the gas phase outlet of the main reactor via a connecting pipe. It is used to centrifugally separate spherical powders that escape with the gas flow. At the same time, a secondary cyclone separator is connected to the end of the primary cyclone separator away from the main reactor via a connecting pipe. The auxiliary reactor, which is a pulse bag filter, has its inlet connected to the gas phase outlet of the secondary cyclone separator and is used to filter and intercept the fine spherical powder particles remaining in the separated gas. The feeding assembly includes a feeding mechanism, a feeding hopper, a powder feeder, a vacuum replacement system, and pipeline valves. The powder feeder adopts a scraper feeding method and has a double hopper design, which is used to continuously transport irregular raw material powder to the feeding inlet of the plasma assembly at a set feeding speed. The powder collection assembly includes multiple collection tanks respectively disposed at the bottom of the main reactor, the first-stage cyclone separator, the second-stage cyclone separator, and the auxiliary reactor, for collecting spherical powder collected at each stage under the protection of an inert atmosphere; A vacuum assembly, which is used to evacuate the equipment and maintain the system pressure within a fixed range during operation; As a further preferred embodiment of this technical solution: the plasma assembly further includes an insulating mounting flange and a metal mounting flange, the plasma cabinet is mounted on the metal mounting flange via the insulating mounting flange, the metal mounting flange is connected to the main reactor, and the metal mounting flange is not energized in the working state; As a further preferred embodiment of this technical solution: the main reactor is a vertical cylindrical structure with a cooling water jacket on its inner wall. The cooling water jacket is equipped with a spiral guide plate. Meanwhile, the gas phase outlet pipe of the main reactor extends upward from the bottom and has a sudden constriction structure. A water cooling system is installed on the main reactor to provide a cooling and crystallization environment for the powder after high-temperature melting. As a further preferred embodiment of this technical solution: both the primary cyclone separator and the secondary cyclone separator are tangential flow cyclone separators, and their outer walls are provided with cooling water jackets. The connecting pipeline between the primary cyclone separator and the secondary cyclone separator is a sleeve-type water-cooled structure. As a further preferred embodiment of this technical solution: the auxiliary reactor includes an upper chamber, a middle chamber, an ash hopper, a filter bag, a perforated plate, and a backwashing device. The backwashing device includes a pulse valve, a blow pipe, a gas storage tank, a flow guide, and a controller, which is used to blow high-pressure gas into the inside of the filter bag to remove the powder accumulated on the outside of the filter bag when the pressure drop at the inlet and outlet of the auxiliary reactor reaches a set value. As a further preferred embodiment of this technical solution: a valve group is provided between the bottom collection tank of the auxiliary reactor and the main body of the auxiliary reactor, the valve group being used to isolate and replace the bottom collection tank without shutting down the reactor. As a further preferred embodiment of this technical solution: the powder collection assembly further includes a vacuum glove box and a sealing machine, used to seal the spherical powder collected at each stage under the protection of an inert atmosphere; As a further preferred embodiment of this technical solution: the vacuum assembly also includes a vacuum exhaust gas filtration system and a water ring pump independent water circulation system, and the flow control cabinet includes 8 gas supply channels, of which 3 are used for the plasma cabinet, 4 are used for the ring cavity protection gas, and 1 is a spare. The pressure of each gas supply channel is controlled to be less than 3MPa. As a further preferred embodiment of this technical solution: the feeding hopper on the feeding assembly is equipped with a real-time humidity monitoring unit and a drying unit, and the feeding hopper is equipped with an anti-clogging structure and an active unblocking mechanism, and the scraper-type feeding mechanism of the powder feeder on the feeding assembly is equipped with adjustable agitator speed, turntable speed and carrier gas speed.

[0006] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, through the synergistic cooperation of the plasma torch and the multi-stage cooling structure, continuous and integrated production from irregular raw material powder to high-purity spherical powder is achieved, which significantly improves the sphericity and fine powder yield. At the same time, the main reactor, cyclone separator and auxiliary reactor sequentially classify and collect particles. Combined with the pulse backflushing cleaning and non-stop discharge design in the auxiliary reactor, not only is tail gas purification and efficient powder recovery guaranteed, but also the continuity of equipment operation and production efficiency are greatly improved.

[0007] 2. In this invention, by integrating a water-cooled jacket, multi-channel precise gas supply control, and a comprehensive intelligent control platform, and through full-process interlocking, automatic pressure feedback adjustment, process curve traceability, and remote / local dual-mode control, the system ensures operational safety and parameter stability under high temperature, high pressure, and high electromagnetic interference environments. At the same time, the vacuum pump group combination design, combined with nitrogen replacement and oxygen content monitoring, effectively avoids powder oxidation and contamination, reduces the intensity of manual intervention, and ensures product quality consistency and long-term operational reliability. Attached Figure Description

[0008] Figure 1 This is a perspective view of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 2 This is a side view of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 3 This is a partial structural schematic diagram of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 4 This is a partial structural schematic diagram of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 5 This is a partial structural schematic diagram of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 6 This is the main control logic diagram of an ultra-high temperature plasma spheroidizing device according to the present invention; Figure 7 This is a flowchart of the ultra-high temperature plasma spheroidizing system of an ultra-high temperature plasma spheroidizing device according to the present invention.

[0009] Legend: 1. Plasma assembly; 101. Plasma cabinet; 102. Power cord; 2. Main reactor; 201. Collection tank; 3. Primary cyclone separator; 4. Secondary cyclone separator; 5. Auxiliary reactor; 6. Feeding assembly; 7. Powder collection assembly; 8. Vacuum assembly. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Example

[0012] Please see Figures 1-7 As shown, the present invention provides a technical solution: an ultra-high temperature plasma spheroidizing device, characterized in that it comprises: Plasma assembly 1, which includes a plasma cabinet 101, a power cord 102, and a gas flow control unit, is used to generate a high-temperature plasma jet. Main reactor 2 is a double-layer stainless steel water-cooled structure. Its top is connected to the outlet of plasma cabinet 101. It is used to receive spherical powder formed after being heated and melted by high-temperature plasma jet, and to perform preliminary cooling and solidification of spherical powder through jacket cooling water. The first-stage cyclone separator 3 is connected to the gas phase outlet of the main reactor 2 via a connecting pipe. It is used to centrifuge the spherical powder that escapes with the airflow. At the same time, the end of the first-stage cyclone separator 3 away from the main reactor 2 is connected to the second-stage cyclone separator 4 via a connecting pipe. Sub-reactor 5 is a pulse bag filter. Its inlet is connected to the gas phase outlet of the secondary cyclone separator 4. It is used to filter and intercept the fine spherical powder particles remaining in the separated gas. The feeding assembly 6 includes a feeding mechanism, a feeding hopper, a powder feeder, a vacuum replacement system, and pipeline valves. The powder feeder adopts a scraper feeding method and has a double hopper design, which is used to continuously transport irregular raw material powder to the feeding inlet of the plasma assembly 1 at a set feeding speed. The powder collection assembly 7 includes multiple collection tanks 201 respectively disposed at the bottom of the main reactor 2, the first-stage cyclone separator 3, the second-stage cyclone separator 4, and the auxiliary reactor 5, for collecting spherical powder collected at each stage under the protection of an inert atmosphere. Vacuum assembly 8 is used to evacuate the equipment and maintain the system pressure within a fixed range during operation.

[0013] Furthermore, this invention discloses a technical solution for an ultra-high temperature plasma spheroidizing device, which is generally adaptable to the high-temperature spheroidizing modification processing of various irregular powders such as metals, ceramics, and alloys. Specifically, the metal and alloy powders include, but are not limited to, one or more of the following: tungsten powder, molybdenum powder, tantalum powder, niobium powder, zirconium powder, hafnium powder, rhenium powder, titanium alloy powder, 718 (In718 high-temperature alloy) powder, 316L powder, 3625 (3625 Hastelloy) powder, Nb521 (niobium alloy) powder, Ta15 (tantalum alloy) powder, GH4251 powder, and SAC (tin powder). The ceramic powders include, but are not limited to, one or more of the following: alumina powder, silicon carbide powder, silicon nitride powder, aluminum nitride powder, yttrium-stabilized zirconium oxide powder, high-purity silicon powder, TiC powder, titanium carbonitride powder, and cast tungsten carbide powder. Graphite powders include graphite powder. The above powders can be used individually. Furthermore, for different materials, the plasma power and supply can be adjusted through a gas flow control unit, a powder feeder, a vacuum component 8, and a water cooling system. The gas flow rate, powder feeding rate, carrier gas velocity, system pressure, and cooling intensity allow irregular raw material powders to melt, spheroidize, and solidify in an ultra-high temperature plasma jet. The powder is then collected in stages through the main reactor 2, primary cyclone separator 3, secondary cyclone separator 4, and auxiliary reactor 5, resulting in high-sphericity, high-purity spherical powders. Powders can also be mixed as needed. This enables fully automated operation, including continuous powder feeding, high-temperature melting and spheroidization, staged cooling, multi-stage separation and dust removal, and inert atmosphere-sealed collection and packaging. It effectively solves industry pain points such as low powder recovery rate, fine powder pollution, easy high-temperature ablation of equipment, easy feed blockage, inability to change materials without stopping the machine, and easy oxidation and deterioration of powders in traditional plasma spheroidization equipment. The equipment consists of eight core modules: plasma component 1, main reactor 2, primary cyclone separator 3, secondary cyclone separator 4, auxiliary reactor 5, feeding component 6, powder collection component 7, and vacuum component 8. These modules work together to achieve high-precision, high-efficiency, and high-purity powder spheroidization production.

[0014] In this embodiment, specifically: the plasma assembly 1 further includes an insulating mounting flange and a metal mounting flange. The plasma cabinet 101 is mounted on the metal mounting flange through the insulating mounting flange. The metal mounting flange is connected to the main reactor 2, and the metal mounting flange is not energized in the working state.

[0015] Furthermore, the plasma cabinet 101 is fixedly installed on the metal mounting flange via an insulating mounting flange. The insulating mounting flange is made of high-strength, high-temperature resistant ceramic insulating material, which can achieve complete electrical isolation between the plasma cabinet 1 and the lower metal structure, eliminating the safety hazards of leakage and short circuit. The metal mounting flange is directly and sealed to the top of the main reactor, and the metal mounting flange is grounded throughout, so it always maintains zero potential and is not energized when the equipment is in operation, completely avoiding equipment breakdown and abnormal powder ionization caused by energized metal parts under high-temperature working conditions.

[0016] In this embodiment, specifically: the main reactor 2 is a vertical cylindrical structure with a cooling water jacket on its inner wall. The cooling water jacket is equipped with a spiral guide plate. At the same time, the gas phase outlet pipe of the main reactor 2 extends upward from the bottom and has a constricted structure. A water cooling system is installed on the main reactor 2 to provide a cooling and crystallization environment for the powder after high-temperature melting.

[0017] Furthermore, the top opening of the main reactor 2 is sealed and connected to the jet outlet of the plasma cabinet 1, allowing it to directly receive the liquid spherical powder formed after being heated and melted by the ultra-high temperature plasma jet. The main reactor 2 has a uniform wall thickness, and a sealed cooling water jacket is formed between the double-layer structure. Spiral guide plates are evenly distributed inside the cooling water jacket, and the cooling water flows spirally from top to bottom along the spiral guide plates, which greatly extends the heat exchange path of the cooling water, eliminates dead zones in local heat exchange in the cavity, and achieves uniform cooling of the entire inner wall of the main reactor 2. This effectively resists the thermal radiation and thermal scouring of the ultra-high temperature plasma, and avoids high-temperature deformation and ablation damage to the cavity.

[0018] In this embodiment, specifically: the primary cyclone separator 3 and the secondary cyclone separator 4 are both tangential flow cyclone separators, and their outer walls are equipped with cooling water jackets. The connecting pipe between the primary cyclone separator 3 and the secondary cyclone separator 4 is a shell-and-tube water-cooled structure.

[0019] Furthermore, this equipment adopts a two-stage tangential cyclone separator series structure, namely a primary cyclone separator 3 and a secondary cyclone separator 4. The two separators work together to complete the graded centrifugal separation of escaped micro powder. The primary cyclone separator 3 is connected to the gas phase outlet of the main reactor 2 through a high-temperature resistant sealed connection pipe. It is mainly used to centrifuge the medium and fine spherical powder particles that escape from the gas flow of the main reactor 2. The secondary cyclone separator 4 is connected to the gas phase outlet of the primary cyclone separator 3 through a sleeve-type water-cooled pipeline. It performs secondary precise separation of the ultrafine powder that was not retained in the primary separation, which greatly improves the overall powder recovery rate. Both the primary cyclone separator 3 and the secondary cyclone separator 4 adopt a tangential feeding structure, with the airflow swirling tangentially along the separator cavity at high speed. Centrifugal force is used to achieve efficient gas-solid separation, which improves the separation efficiency by more than 20% compared to traditional direct-flow separators. The outer walls of both cyclone separators are integrally equipped with cooling water jackets to continuously cool the high-temperature gas-solid mixture entering the separator, accelerate the solidification and molding of ultrafine powder, and prevent the high-temperature powder from sticking and agglomerating. At the same time, the connecting pipeline between the primary cyclone separator 3 and the secondary cyclone separator 4 adopts a sleeve-type water-cooling structure, with circulating cooling water flowing between the inner and outer layers of the pipeline. This can continuously cool the high-temperature airflow flowing inside the pipeline, prevent high-temperature deformation of the pipeline and powder from sticking to the wall and clogging, and ensure smooth airflow. The gas phase outlet of the two cyclone separators at the end away from the main reactor 2 is connected to the subsequent dust removal equipment through pipelines to achieve step-by-step purification of the airflow.

[0020] In this embodiment, specifically: the auxiliary reactor 5 includes an upper chamber, a middle chamber, an ash hopper, a filter bag, a tube sheet, and a backwashing device. The backwashing device includes a pulse valve, a blowpipe, a gas storage tank, a flow guide, and a controller. It is used to blow high-pressure gas into the inside of the filter bag to remove the powder accumulated on the outside of the filter bag when the pressure drop at the inlet and outlet of the auxiliary reactor 5 reaches a set value.

[0021] Further: The tube sheet is fixed between the upper and middle chambers to uniformly suspend the array of high-precision filter bags. When the pulse bag filter is working, the dust-laden gas enters the ash hopper from the bottom of the chamber. Due to the sudden expansion of the airflow cross-sectional area and the decrease in flow velocity, some of the coarse and dense dust particles in the airflow settle down in the ash hopper under the action of gravity. The fine and low-density dust particles enter the bag filter chamber and, through the combined effects of inertia, collision, sieving, interception and electrostatics on the surface of the filter bag, the dust settles on the surface of the filter bag and forms a dust layer. The purified gas enters the clean air chamber and is discharged by the exhaust pipe through the fan. Among them, the resistance value of the bag filter increases with the increase of the thickness of the dust layer on the surface of the filter bag. During this process, the resistance at any time during filtration is... The value can be obtained by the following formula: ; In the formula, The filtration velocity is m / s. The gas dynamic viscosity coefficient is Pa·s. The initial dust content of the gas is kg / m3, A and B are coefficients that depend on the porosity, geometric properties and gas dynamic characteristics of the filter material, and their values ​​are determined by experimental methods, and t is time; Furthermore, when its resistance value reaches a certain specified value, jet cleaning must be performed, under a given dust collector pressure drop Δp. min In this case, the required cleaning cycle t can be calculated using the following formula. p : ： ; The symbols in the formula have the same meaning as before; Pulse jet cleaning is controlled by a pulse controller (or PLC) that controls the opening and closing of the pulse valve. When the pulse valve is open, the compressed air in the air tank is injected through the pulse valve and small holes on the jet pipe into the filter bag opening. This creates an induced airflow that is several times the volume of the induced airflow and enters the filter bag, causing an instantaneous positive pressure inside the filter bag and rapid expansion. The dust deposited on the outside of the filter bag falls off and into the ash hopper, thus achieving the purpose of cleaning.

[0022] In this embodiment, specifically: a valve group is provided between the bottom collection tank 201 of the auxiliary reactor 5 and the main body of the auxiliary reactor 5. The valve group is used to isolate and replace the bottom collection tank 201 without shutting down the reactor.

[0023] Furthermore, an independent valve group is specially installed between the bottom collection tank 201 of the auxiliary reactor 5 and the main body of the equipment. This valve group adopts a double-valve linkage sealing structure, which can independently isolate the bottom collection tank 201 without stopping the equipment, depressurizing the system, or disrupting the inert atmosphere. Operators can directly disassemble and replace the collection tank to complete the powder unloading operation, thus completely solving the problem that traditional dust removal equipment requires shutdown for unloading, which affects the continuity of production.

[0024] In this embodiment, specifically: the powder collection component 7 also includes a vacuum glove box and a sealing machine, used to seal the spherical powder collected at each stage under the protection of an inert atmosphere.

[0025] Furthermore, the powder collection operation is completed under the protection of an inert atmosphere throughout the entire process. Specifically, the raw material powder is automatically packaged and unloaded under the protection of the atmosphere (nitrogen, argon, helium). The temperature of the spherical powder is detected at the bottom of the collection tank 201. The collection valve is opened only after the temperature meets the requirements. At the same time, the collection tank 201 is sealed and connected to the equipment cavity, preventing the outside air from mixing in and avoiding oxidation and deterioration of the high-temperature spherical powder during the cooling process. In addition, the equipment is equipped with an integrated vacuum glove box and an automated packaging machine. After the powder is collected, the powder sampling, transfer and packaging operations can be completed directly in the inert atmosphere sealed environment. The collection system is equipped with a quick-opening window for easy removal of the packaged sample, which can accommodate the space for two-hand operation. Finally, the packaged powder can be directly stored or used in subsequent production without secondary processing.

[0026] In this embodiment, specifically: the vacuum assembly 8 also includes a vacuum exhaust gas filtration system and a water ring pump independent water circulation system. The flow control cabinet includes 8 gas supply channels, of which 3 are for use by the plasma cabinet 101, 4 are for use by the ring cavity protection gas, and 1 is a spare. The pressure control of each gas supply channel is less than 3MPa.

[0027] Further details: Vacuum assembly 8 mainly consists of a water ring vacuum pump, a mechanical vacuum pump, matching stainless steel pipelines and ferrules / VCR connectors, a pneumatic diaphragm regulating valve and a shut-off valve; The water ring vacuum pump is installed at the end of the vacuum pipeline, near the exhaust port, to treat the tail gas from the auxiliary reactor 5. For example, it is installed after the gas phase outlet of the auxiliary reactor 5, so that after the gas flows through the main reactor 2, the cyclone separator and the auxiliary reactor 5, it is finally extracted by the water ring vacuum pump and discharged into the tail gas treatment system. The mechanical vacuum pump is connected in parallel with the main pumping pipe of the water ring vacuum pump through a bypass pipe, and valves are installed on the inlet and outlet pipes to isolate it after the pre-vacuuming is completed, and then the water ring vacuum pump is switched to run alone. The pneumatic diaphragm regulating valve is installed on the vacuum pipeline between the gas phase outlet of the main reactor 2 and the water ring vacuum pump. It is used to adjust the pumping volume at this point in real time, thereby controlling the pressure of the entire system. Specifically, the valve opening is adjusted before the suction inlet of the water ring vacuum pump and the mechanical vacuum pump to control the flow rate of gas pumped out of the system by the downstream pump group. The shut-off valve is installed on the upstream and downstream gas phase pipelines connected to the sub-reactor 5. It is used to automatically trigger the interlock by the control system in abnormal operating conditions, quickly cut off the passage between the sub-reactor 5 and the upstream and downstream, realize isolation protection, and prevent high pressure gas from impacting the filter bag or causing powder backflow. Meanwhile, the gas flow control unit is equipped with multiple independent gas supply channels, with a total of 8 gas supply channels. Specifically, 3 channels are dedicated to supplying the plasma cabinet 101, 4 channels are used to supply inert annular protective gas to each cavity of the equipment, and the remaining channel is a spare channel. This can adapt to the gas supply expansion needs of different powder processing conditions. Each gas supply channel is equipped with an independent pressure sensor, flow regulating valve, and pressure stabilizing device, so that the pressure of the plasma cabinet 101 and the spare channel is controlled to be less than 3 MPa, and the flow rate is controlled to be 0-200 slm. The pressure of the 4 annular protective gas channels is controlled to be less than 3 MPa, and the flow rate is controlled to be 0-500 slm.

[0028] In this embodiment, specifically: the feeding hopper on the feeding assembly 6 is equipped with a real-time humidity monitoring unit and a drying unit, and the feeding hopper is equipped with an anti-blocking structure and an active unblocking mechanism, and the scraper-type feeding mechanism of the powder feeder on the feeding assembly 6 is equipped with adjustable agitator speed, turntable speed and carrier gas speed.

[0029] Furthermore, the feeding hopper integrates a real-time humidity monitoring unit and a hot air drying unit. The humidity monitoring unit can collect the humidity data of the powder in the hopper in real time. When the humidity exceeds the set threshold, the drying unit will automatically start to perform constant temperature hot air drying, effectively removing the moisture adsorbed by the raw material powder and avoiding defects such as powder clumping due to moisture and hollow powder or cracked powder after spheroidization. At the same time, the feeding hopper is equipped with a conical anti-blocking structure and an active spiral unblocking mechanism, which can actively disturb and unblock the bridging and accumulated powder, eliminating the problems of material blockage and material interruption in the feeding hopper. The powder feeder adopts a dual-hopper scraper-type feeding design, with the two hoppers feeding alternately to achieve uninterrupted continuous feeding, avoiding the downtime of single-hopper feeding, and greatly improving production efficiency. The scraper-type feeding mechanism is equipped with multi-dimensional adjustable operating parameters, which can precisely adjust the agitator speed, turntable feeding speed and carrier gas conveying speed according to the density, particle size and flowability of different powders, to achieve quantitative feeding, ensure uniform and stable feeding, and ensure that every powder particle can fully enter the plasma jet area to complete melting and spheroidization.

[0030] Working principle or structural principle: First, the entire cavity of the device is evacuated to 10°C using vacuum assembly 8. - ¹Pa, then the vacuum pump group is shut down and high-purity nitrogen is introduced to a slightly positive pressure. The vacuuming-nitrogen filling operation is repeated several times until the oxygen content in the system is lower than the process set value, completing the inert gas replacement. The system pressure is then adjusted to the working standard value to ensure that the entire production process is carried out in a low-oxygen clean environment, effectively preventing high-temperature oxidation of the powder. Then, the feeding component 6 is started, and the feeding hopper completes the powder drying and anti-clogging. The scraper-type powder feeder continuously feeds the irregular raw material powder into the feed port of the plasma component 1 at a set speed. The plasma component 1 precisely controls the process gas through the gas flow control unit to generate an ultra-high temperature plasma jet. The raw material powder is fully melted in the jet area, and the surface tension contracts to form liquid spherical powder. The spherical powder enters the main reactor. 2. After initial cooling and solidification by a double-layer water-cooled jacket, large powder particles settle directly to the bottom of the main reactor 2 for collection. The airflow containing fine powder enters a two-stage cyclone separator through an inclined constriction outlet. The first-stage cyclone separator 3 and the second-stage cyclone separator 4 use centrifugal force to classify and intercept medium and fine spherical powders. The entire process is water-cooled to refine the powder solidification effect. The unseparated ultrafine powder enters the auxiliary reactor 5 with the airflow and is precisely filtered and intercepted by a pulse bag filter. At the same time, the pulse jet cleaning device automatically cleans the dust to ensure continuous operation of the equipment. The spherical powders separated and collected at each stage fall into the corresponding collection tanks 201. Finally, the powder is sealed and encapsulated under the protection of an inert atmosphere. The entire process is automated, with high spheroidization efficiency, high powder purity, no material waste, and no environmental pollution.

[0031] 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 high-temperature plasma spheroidizing device, characterized in that, include: Plasma assembly (1), the plasma assembly (1) includes a plasma cabinet (101), a power cord (102), and a gas flow control unit, for generating a high-temperature plasma jet; The main reactor (2) is a double-layer stainless steel water-cooled structure. Its top is connected to the outlet of the plasma cabinet (101) to receive the spherical powder formed after being heated and melted by the high-temperature plasma jet, and to preliminarily cool and solidify the spherical powder by the jacket cooling water. A primary cyclone separator (3) is connected to the gas phase outlet of the main reactor (2) via a connecting pipe. It is used to centrifuge the spherical powder that escapes with the airflow. At the same time, a secondary cyclone separator (4) is connected to the end of the primary cyclone separator (3) away from the main reactor (2) via a connecting pipe. The auxiliary reactor (5) is a pulse bag filter, whose inlet is connected to the gas phase outlet of the secondary cyclone separator (4) for filtering and intercepting the fine spherical powder particles remaining in the separated gas. The feeding assembly (6) includes a feeding mechanism, a feeding bin, a powder feeder, a vacuum replacement system and pipeline valves. The powder feeder adopts a scraper feeding method and has a double hopper design, which is used to continuously transport irregular raw material powder to the feeding inlet of the plasma assembly (1) at a set feeding speed. The powder collection assembly (7) includes multiple collection tanks (201) respectively disposed at the bottom of the main reactor (2), the first-stage cyclone separator (3), the second-stage cyclone separator (4), and the auxiliary reactor (5), for collecting spherical powder collected at each stage under the protection of an inert atmosphere; Vacuum assembly (8) is used to evacuate the equipment and maintain the system pressure within a fixed range during operation.

2. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The plasma assembly (1) also includes an insulating mounting flange and a metal mounting flange. The plasma cabinet (101) is mounted on the metal mounting flange via the insulating mounting flange. The metal mounting flange is connected to the main reactor (2), and the metal mounting flange is not energized in the working state.

3. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The main reactor (2) is a vertical cylindrical structure with a cooling water jacket on its inner wall. The cooling water jacket is equipped with a spiral guide plate. The gas phase outlet pipe of the main reactor (2) extends upward from the bottom and has a sudden contraction structure. The main reactor (2) is equipped with a water cooling system to provide a cooling and crystallization environment for the powder after high-temperature melting.

4. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: Both the primary cyclone separator (3) and the secondary cyclone separator (4) are tangential cyclone separators, and their outer walls are equipped with cooling water jackets. The connecting pipe between the primary cyclone separator (3) and the secondary cyclone separator (4) is a sleeve-type water-cooled structure.

5. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The auxiliary reactor (5) includes an upper chamber, a middle chamber, an ash hopper, a filter bag, a tube sheet, and a backwashing device. The backwashing device includes a pulse valve, a blow pipe, a gas storage tank, a flow guide, and a controller. It is used to blow high-pressure gas into the inside of the filter bag to remove the powder accumulated on the outside of the filter bag when the pressure drop at the inlet and outlet of the auxiliary reactor (5) reaches a set value.

6. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: A valve group is provided between the bottom collection tank (201) of the sub-reactor (5) and the main body of the sub-reactor (5). The valve group is used to isolate and replace the bottom collection tank (201) without shutting down the reactor.

7. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The powder collection assembly (7) also includes a vacuum glove box and a sealing machine for sealing the spherical powder collected at each stage under an inert atmosphere.

8. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The vacuum assembly (8) also includes a vacuum exhaust gas filtration system and an independent water circulation system for the water ring pump. The flow control cabinet includes 8 gas supply channels, of which 3 are used by the plasma cabinet (101), 4 are used by the ring cavity protection gas, and 1 is a spare. The pressure control of each gas supply channel is less than 3MPa.

9. The ultra-high temperature plasma spheroidizing device according to claim 1, characterized in that: The feeding hopper on the feeding assembly (6) is equipped with a real-time humidity monitoring unit and a drying unit, and the feeding hopper is equipped with an anti-blocking structure and an active unblocking mechanism. The scraper feeding mechanism of the powder feeder on the feeding assembly (6) is equipped with adjustable agitator speed, turntable speed and carrier gas speed.

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