Precise feeding device for toxic powder based on inert gas protection

Abstract

This invention relates to the field of powder feeding equipment technology, and more particularly to a precise feeding device for toxic powders based on inert gas protection. The device includes a feeding tower, a powder storage mechanism, a weighing and metering mechanism, a screw conveyor mechanism, an inert gas protection mechanism, a tail gas treatment mechanism, a sealing and isolation mechanism, and a control mechanism. The control mechanism includes a powder feeding accuracy control module, an inert gas protection safety module, and a collaborative execution module. This invention achieves synergistic optimization of feeding accuracy and safety protection, improving feeding accuracy to ±0.3% and stably controlling oxygen concentration below the safety threshold. It is suitable for the closed and precise feeding of toxic powders in the chemical, pharmaceutical, and new materials production fields.

Description

Technical Field

[0001] This invention relates to the field of powder feeding equipment technology, and in particular to a precise feeding device for toxic powders based on inert gas protection. Background Technology

[0002] In the fields of chemical, pharmaceutical, and new materials production, the feeding of toxic powders (such as arsenic trioxide, sodium cyanide, and certain heavy metal powders) is highly dangerous. Powder leaks not only cause serious environmental pollution but also directly threaten the lives of operators. Furthermore, toxic powders readily react with oxygen in the air during the feeding process, potentially causing combustion, explosion, or the production of toxic byproducts. Therefore, feeding must be carried out in a closed system under inert gas protection.

[0003] The existing technology has the following main drawbacks: First, traditional feeding devices rely on a screw conveyor with a fixed rotation speed, failing to consider the dynamic changes in powder properties (particle size distribution, moisture content, bulk density, angle of repose). When powder moisture increases or particle size decreases, flowability drops sharply, leading to unstable feeding flow rate, large deviations in metering accuracy, and in severe cases, powder bridging and blockage. Second, existing devices lack a real-time weighing feedback and calibration mechanism, setting the feeding amount only through a single weighing, without considering instantaneous flow fluctuations and cumulative weighing deviations during the screw conveying process, resulting in significant deviations between the actual feeding amount and the set value. First, in scenarios where the formulation requirements for fine chemicals are strict, product quality may fail. Second, the existing inert gas protection system uses a fixed flow rate and does not dynamically adjust according to the real-time changes in oxygen concentration inside the reactor. When the feed port is opened or the seal fails, the oxygen concentration rises suddenly and cannot be compensated in time, posing an explosion risk. Third, the existing equipment does not consider the impact and damage to the inert gas protection layer caused by feeding disturbances. When the instantaneous flow rate of the screw conveyor changes suddenly, a negative pressure suction effect is formed at the feed port, which draws external air into the reactor and destroys the inert atmosphere. The fixed flow rate of the protective gas cannot compensate for this quickly.

[0004] For example, Chinese patent CN220386451U discloses a precise feeding and mixing device for epoxy powder raw materials. However, this solution still uses a solenoid valve with a fixed opening to control the discharge, without establishing a basic feeding scheme based on powder physical property parameters. It lacks a mechanism for dynamically correcting the feeding process based on real-time weighing residual data, and it does not perform secondary optimization of the corrected feeding scheme based on environmental disturbance parameters. This results in a significant decrease in feeding accuracy when powder physical properties change or the environment fluctuates. Furthermore, it does not have an inert gas protection mechanism, making it unable to achieve airtight protection during the feeding of toxic powders. It also lacks a three-layer logic safety control function that generates a basic protection scheme based on reactor pressure parameters, corrects it based on real-time oxygen concentration monitoring data, and performs secondary compensation based on feeding disturbance feedback parameters. Therefore, it is not suitable for inert atmosphere airtight feeding scenarios of toxic powders.

[0005] Chinese patent CN120285872A discloses an automated feeding system, but this solution still only uses a high-precision weigher for single-time measurement and judgment, without establishing a basic feeding scheme generation mechanism based on powder physical property parameters. It lacks the logic to perform a first-time calibration of the basic feeding scheme based on real-time weighing residual data, and it also lacks a secondary optimization of the calibration process based on environmental disturbance parameters. This results in a disconnect between weighing feedback and feeding control, and the feeding accuracy cannot be guaranteed. Furthermore, its dual-purpose pump is only used to adsorb scattered materials to prevent waste, and it does not establish an inert gas protective atmosphere. It does not generate a basic protection scheme based on the reactor pressure parameters, lacks a mechanism to dynamically correct the protective gas flow rate based on real-time oxygen concentration monitoring data, and it also lacks a secondary compensation for the corrected protection scheme based on feeding disturbance feedback parameters. It cannot stably control the oxygen concentration in the reactor below the safety threshold, and it does not have the function of forming a positive pressure barrier to prevent powder leakage and external air infiltration through a sealed shell gas-filled sealing structure. Therefore, it is not suitable for explosion-proof and safe feeding scenarios of toxic powders. Summary of the Invention

[0006] To address these issues, the present invention provides a precise feeding device for toxic powders based on inert gas protection, which overcomes the technical problems in the prior art, such as low precision due to fixed-speed feeding, lack of weighing feedback calibration, failure of oxygen concentration control due to fixed inert gas supply, and disruption of the inert atmosphere caused by feeding disturbance.

[0007] To achieve the above objectives, the present invention provides a precise feeding device for toxic powders based on inert gas protection, comprising: Feeding tower body, powder storage mechanism, weighing and metering mechanism, screw conveyor mechanism, inert gas protection mechanism, exhaust gas treatment mechanism, sealing and isolation mechanism and control mechanism; The powder storage mechanism is connected to the top of the feeding tower body; the weighing and metering mechanism is located below the powder storage mechanism and connected to the screw conveyor mechanism, which extends into the interior of the feeding tower body; the inert gas protection mechanism is connected to the side wall and bottom of the feeding tower body; the exhaust gas treatment mechanism is connected to the top of the feeding tower body; and the sealing and isolation mechanism is located at the feeding port of the feeding tower body; the control mechanism is electrically connected to the weighing and metering mechanism, the screw conveyor mechanism, the inert gas protection mechanism, and the exhaust gas treatment mechanism, respectively. The control mechanism includes: The powder feeding accuracy control module is used to generate a basic feeding scheme based on powder physical property parameters, to perform a first verification of the generation process of the basic feeding scheme based on real-time weighing residual data to obtain a verified feeding scheme, and to perform a second optimization of the first verification process based on environmental disturbance parameters to obtain a target feeding scheme. An inert gas protection safety module is used to generate a basic protection scheme based on the reactor pressure parameters, to make a first correction to the generation process of the basic protection scheme based on real-time oxygen concentration monitoring data to obtain a corrected protection scheme, and to make a second compensation to the first correction process based on the feeding disturbance feedback parameters to obtain a target protection scheme. The collaborative execution module is used to control the rotational speed of the screw conveyor according to the target feeding scheme and to control the flow rate of the inert gas protection mechanism according to the target protection scheme.

[0008] After adopting the above technical solution, the present invention has the following advantages: The basic feeding scheme is generated by using powder physical property parameters, ensuring that the initial screw speed matches the powder flowability, thus solving the problem of powder bridging or over-feeding caused by a fixed speed in the prior art; the basic feeding scheme is calibrated once using real-time weighing residual data, and the screw speed is dynamically corrected based on instantaneous and cumulative weighing deviations, achieving closed-loop control of the feeding flow rate and improving the feeding accuracy to within three per thousand; the initial calibration process is further optimized using environmental disturbance parameters, suppressing the coupling effect of environmental disturbances on feeding accuracy based on temperature change rate, humidity change rate, and vibration acceleration amplitude, ensuring accuracy even in harsh conditions. Stability of feeding under adverse operating conditions: The basic protection scheme is generated based on the reactor pressure parameters, and the inert gas requirement is calculated according to the ideal gas law to match the initial protective gas flow rate with the reactor operating conditions. The basic protection scheme is corrected once by real-time oxygen concentration monitoring data. The inert gas flow rate is dynamically increased or decreased according to the current oxygen concentration and the rate of change of oxygen concentration to stabilize the oxygen concentration in the reactor below the safety threshold. The feeding disturbance feedback parameters are used to perform secondary compensation for the first correction process. The protective gas flow rate is quickly compensated according to the instantaneous flow fluctuation and pressure pulsation at the feeding port to offset the damage of feeding disturbance to the inert atmosphere and ensure that the oxygen concentration does not exceed the standard throughout the feeding process.

[0009] Furthermore, the step of generating a basic feeding scheme based on powder physical property parameters includes: The powder physical properties parameters are obtained, including powder particle size distribution d, powder moisture content h, powder bulk density ρ, and powder angle of repose θ. The powder flow index Φ is calculated based on the powder particle size distribution d, the powder humidity h, the powder bulk density ρ, and the powder angle of repose θ. Φ is defined as ξ×d / d0+δ×h / h0+ε×ρ / ρ0+ζ×θ / θ0, where d0 is the reference particle size, h0 is the reference humidity, ρ0 is the reference bulk density, θ0 is the reference angle of repose, ξ is the first property weight, δ is the second property weight, ε is the third property weight, and ζ is the fourth property weight. The basic screw speed n0 is calculated based on the powder flow index Φ, and n0 is set as n0 = nmax × (1 - Φ / Φmax), where nmax is the maximum allowable screw speed and Φmax is the maximum powder flow index. The basic feed flow rate q0 is calculated based on the basic screw rotation speed n0, and q0 is set as k×n0×ρ×A, where k is the screw conveying coefficient and A is the cross-sectional area of ​​the screw blade. The basic screw rotation speed n0 and the basic feeding flow rate q0 are output as the basic feeding scheme.

[0010] By adopting the aforementioned technical solution, the powder flowability is comprehensively characterized by the powder flow index. The smaller the particle size, the higher the humidity, and the larger the angle of repose, the worse the flowability. The basic screw speed is reduced accordingly to avoid bridging and blockage. At the same time, the higher the bulk density, the higher the mass per unit volume, and the basic feed flow rate is increased accordingly, so as to achieve precise matching between the feed parameters and the powder properties.

[0011] Furthermore, the process of generating the basic feeding scheme based on real-time weighing residual data is calibrated to obtain a calibrated feeding scheme, including: The real-time weighing residual data is acquired, and the real-time weighing residual data includes instantaneous weighing deviation Δm and cumulative weighing deviation Σm. The weighing deviation index Ψ is calculated based on the instantaneous weighing deviation Δm, the cumulative weighing deviation Σm, the first deviation weight ω1, and the second deviation weight ω2. Ψ is set as ω1×|Δm| / Δmmax+ω2×|Σm| / Σmmax, where Δmmax is the maximum permissible instantaneous deviation and Σmmax is the maximum permissible cumulative deviation. The weighing deviation index Ψ is compared with the preset deviation index Ψ0. Based on the comparison result, the feeding accuracy is judged, and based on the judgment result, the basic feeding scheme is calibrated once, wherein: When Ψ≤Ψ0, the feeding accuracy is determined to be normal, and no calibration is performed on the basic feeding scheme. When Ψ>Ψ0, the feeding accuracy is determined to be abnormal. The basic feeding scheme is then calibrated to obtain the calibrated screw speed n1. n1 is set as n0×[1-χ×(Ψ-Ψ0) / Ψmax], where χ is the speed correction coefficient and Ψmax is the maximum weighing deviation index. The calibrated screw speed n1 is then replaced in the basic feeding scheme to obtain the calibrated feeding scheme.

[0012] Using the aforementioned technical solution, the instantaneous weighing deviation reflects the fluctuation of the feed flow rate at the current moment, and the cumulative weighing deviation reflects the systematic deviation of long-term operation. The two are weighted to form a weighing deviation index. When the deviation exceeds the threshold, the screw speed is automatically reduced to suppress overshoot, thereby realizing real-time closed-loop correction of the feed flow rate.

[0013] Furthermore, the secondary optimization of the first calibration process based on environmental disturbance parameters to obtain the target feeding scheme includes: The environmental disturbance parameters are acquired, including the rate of change of ambient temperature τ, the rate of change of ambient humidity φ, and the amplitude of vibration acceleration a. The disturbance gain coefficient Γ is calculated based on the ambient temperature change rate τ, the ambient humidity change rate φ, the vibration acceleration amplitude a, the first disturbance weight α, the second disturbance weight β, and the third disturbance weight γ. Γ is set as α×|τ| / τmax+β×|φ| / φmax+γ×|a| / amax, where τmax is the maximum temperature change rate threshold, φmax is the maximum humidity change rate threshold, and amax is the maximum vibration acceleration threshold. The perturbation gain coefficient Γ is compared with the preset gain coefficient Γ0. Based on the comparison result, the perturbation coupling state is judged, and the first calibration process is optimized a second time based on the judgment result, wherein: When Γ≤Γ0, the disturbance coupling state is determined to be stable coupling, and no secondary optimization is performed on the first calibration process; When Γ>Γ0, the disturbance coupling state is determined to be strong coupling. The first calibration process is then optimized to obtain the target spiral speed n2. n2 is set to n1×[1-η×(Γ-Γ0) / Γmax], where η is the coupling suppression coefficient and Γmax is the maximum disturbance gain. The target spiral speed n2 is then replaced in the calibration feeding scheme to obtain the target feeding scheme.

[0014] Using the aforementioned technical solution, changes in ambient temperature cause changes in the thickness of the water film adsorbed on the powder surface, changes in ambient humidity directly affect the powder flowability, and vibration acceleration interferes with the stability of the weighing sensor signal. The three factors are weighted together to form a disturbance gain coefficient. When the disturbance exceeds the threshold, the screw speed is further reduced to suppress the environmental coupling effect and ensure the stability of the feeding accuracy under harsh working conditions.

[0015] Furthermore, the generation of a basic protection scheme based on the reactor pressure parameters includes: The pressure parameters of the reactor are acquired, including the initial pressure p, the volume v, and the temperature t. The inert gas requirement g0 is calculated based on the initial pressure p of the reactor, the volume v of the reactor, the temperature t of the reactor, and the gas state constant r, and g0 is set as p × v / (r × t). The basic inert gas flow rate f0 is calculated based on the inert gas demand g0, and f0 is set as g0 / tc, where tc is the feeding cycle length. The basic inert gas pressure p0 is calculated based on the basic inert gas flow rate f0, and p0 is set as μ×f0 / (π×d2 / 4), where μ is the pipeline resistance coefficient and d is the diameter of the inert gas pipeline. The basic inert gas flow rate f0 and the basic inert gas pressure p0 are output as the basic protection scheme.

[0016] By adopting the aforementioned technical solution, the inert gas demand is calculated using the ideal gas law, which matches the basic protective gas flow rate with the reactor volume, pressure, and temperature, avoiding insufficient or excessive supply of protective gas and achieving accurate budgeting of inert gas usage.

[0017] Furthermore, the process of generating the basic protection scheme based on real-time oxygen concentration monitoring data is modified to obtain a modified protection scheme, including: The real-time oxygen concentration monitoring data is acquired, including the current oxygen concentration c and the oxygen concentration change rate dc; The oxygen concentration correction coefficient Ω is calculated based on the current oxygen concentration c, the oxygen concentration change rate dc, the first oxygen concentration weight λ1, and the second oxygen concentration weight λ2. The formula is Ω = λ1 × c / cmax + λ2 × |dc| / dcmax, where cmax is the maximum allowable oxygen concentration and dcmax is the maximum allowable oxygen concentration change rate. The oxygen concentration correction coefficient Ω is compared with the preset correction coefficient Ω0. The sealing status is judged based on the comparison result, and the basic protection scheme is modified once based on the judgment result, wherein: When Ω≤Ω0, the sealing condition is determined to be good, and no modification is made to the basic protection scheme. When Ω > Ω0, the sealing condition is determined to be at risk of leakage. The basic protection scheme is modified to obtain the modified inert gas flow rate f1. f1 is set as f0 × [1 + σ × (Ω - Ω0) / Ωmax], where σ is the flow rate correction coefficient and Ωmax is the maximum oxygen concentration correction coefficient. The modified inert gas flow rate f1 is replaced in the basic protection scheme to obtain the modified protection scheme.

[0018] Using the aforementioned technical solution, the current oxygen concentration reflects the overall quality of the inert atmosphere inside the reactor, and the oxygen concentration change rate reflects the urgency of the seal leak. The two are weighted together to form an oxygen concentration correction coefficient. When the oxygen concentration is abnormal, the inert gas flow rate is automatically increased to quickly dilute the oxygen and bring the oxygen concentration back to the safe range.

[0019] Furthermore, the secondary compensation of the first correction process based on the material feeding disturbance feedback parameters to obtain the target protection scheme includes: The feeding disturbance feedback parameters are acquired, including the instantaneous flow rate fluctuation δq and the pressure pulsation at the feeding port δp; The feeding disturbance index Y is calculated based on the instantaneous flow fluctuation δq, the pressure pulsation at the feeding port δp, the first disturbance weight κ1, and the second disturbance weight κ2. Y is set as κ1×|δq| / δqmax+κ2×|δp| / δpmax, where δqmax is the maximum allowable flow fluctuation and δpmax is the maximum allowable pressure pulsation. The feeding disturbance index Y is compared with the preset disturbance index Y0. Based on the comparison result, the disturbance risk status is judged, and based on the judgment result, a second compensation is performed on the first correction process, wherein: When Y≤Y0, the disturbance risk status is determined to be controllable, and no secondary compensation is performed on the first correction process. When Y > Y0, the disturbance risk status is determined to be high-risk. The first correction process is then compensated twice to obtain the target inert gas flow rate f2. f2 is set as f1 × [1 + ρ × (Y - Y0) / Ymax], where ρ is the compensation gain coefficient and Ymax is the maximum feed disturbance index. The target inert gas flow rate f2 is then replaced in the corrected protection scheme to obtain the target protection scheme.

[0020] Using the aforementioned technical solution, the instantaneous flow fluctuation of the feed causes a sudden change in the momentum of the powder at the feed port, forming a local negative pressure suction effect. The pressure pulsation at the feed port directly reflects the degree of damage to the inert gas protective layer. The two are weighted to synthesize the feed disturbance index. When the disturbance exceeds the threshold, the inert gas flow rate is rapidly increased to offset the negative pressure effect and prevent external air from being drawn into the reactor.

[0021] Furthermore, the powder storage mechanism includes a storage tank, an arch-breaking device, and a level sensor; the arch-breaking device is disposed on the inner wall of the storage tank, and the level sensor is disposed on the top of the storage tank and electrically connected to the control mechanism; the storage tank is made of 316L stainless steel, and the inner wall is electropolished with a surface roughness Ra≤0.4μm.

[0022] Using the aforementioned technical solution, 316L stainless steel has excellent corrosion resistance. Electropolishing treatment makes the inner wall surface smooth, and the surface roughness Ra≤0.4μm can effectively reduce the adhesion between the powder and the tank wall and prevent the powder from sticking to the wall and clumping. The arch-breaking device mechanically vibrates to break the arch when the powder is bridging, and the material level sensor monitors the storage amount in real time and feeds it back to the control mechanism.

[0023] Furthermore, the weighing and metering mechanism includes a weighing sensor, a metering hopper, and a discharge valve; the weighing sensor is an electromagnetic force-compensated weighing sensor with an accuracy class of C3 and a graduation value of no more than 0.1g; the metering hopper adopts a conical design with a cone angle of 60°, and its bottom is connected to the screw conveyor mechanism.

[0024] Using the aforementioned technical solution, the electromagnetic force-compensated weighing sensor has an accuracy level of C3 and a graduation value of no more than 0.1g, which can meet the high-precision metering requirements of toxic powders; the 60° cone angle design of the metering hopper ensures that the powder slides smoothly into the screw conveyor mechanism, avoiding dead corners and material accumulation.

[0025] Furthermore, the screw conveying mechanism includes a variable frequency motor, a screw shaft, and a sealing housing; the screw shaft adopts a variable pitch design, with the pitch at the feed end being 1.5 times that at the discharge end; the connection between the sealing housing and the feeding tower body adopts an air-filled sealing structure, with the air pressure being 0.02 MPa higher than the pressure inside the tower.

[0026] Using the aforementioned technical solution, the variable pitch design makes the pitch at the feed end greater than that at the discharge end. The feed end forms a loose fill to facilitate powder entry, while the discharge end forms a dense fill to prevent powder backflow. The air-filled sealing structure maintains a sealing air pressure 0.02 MPa higher than the pressure inside the tower, forming a positive pressure barrier to prevent powder leakage and external air infiltration. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the precise feeding device for toxic powder based on inert gas protection in this embodiment; Figure 2 This is a schematic diagram of the control mechanism. Figure 3 This is a structural diagram of the powder feeding accuracy control module; Figure 4 A schematic diagram of the inert gas protection safety module; In the diagram: 1. Feeding tower body; 2. Storage tank; 3. Arch breaking device; 4. Material level sensor; 5. Weighing sensor; 6. Metering hopper; 7. Discharge valve; 8. Variable frequency motor; 9. Screw shaft; 10. Sealed shell; 11. Inert gas inlet pipe; 12. Flow regulating valve; 13. Pressure sensor; 14. Oxygen concentration sensor; 15. Tail gas treatment tank; 16. Inlet pipe; 17. Outlet pipe; 18. Sealed isolation door; 19. Control mechanism; 20. Reactor. Detailed Implementation

[0028] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0029] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0030] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0031] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] like Figure 1 As shown, the present invention provides a precise feeding device for toxic powder based on inert gas protection, including a feeding tower body 1, a powder storage mechanism, a weighing and metering mechanism, a screw conveying mechanism, an inert gas protection mechanism, a tail gas treatment mechanism, a sealing and isolation mechanism, and a control mechanism 19.

[0033] The powder storage mechanism is connected to the top of the feeding tower 1, the weighing and metering mechanism is located below the powder storage mechanism and connected to the screw conveyor mechanism, and the screw conveyor mechanism extends into the interior of the feeding tower 1; the inert gas protection mechanism is connected to the side wall and bottom of the feeding tower 1, the exhaust gas treatment mechanism is connected to the top of the feeding tower 1, and the sealing and isolation mechanism is located at the feeding port of the feeding tower 1; the control mechanism 19 is electrically connected to the weighing and metering mechanism, the screw conveyor mechanism, the inert gas protection mechanism, and the exhaust gas treatment mechanism respectively.

[0034] In this embodiment, the powder storage mechanism includes a storage tank 2, an arch-breaking device 3, and a level sensor 4. The storage tank 2 has a volume of 0.5 cubic meters, is made of 316L stainless steel, has a wall thickness of 4 mm, and its inner wall is electropolished with a surface roughness Ra=0.3μm. The arch-breaking device 3 is a pneumatic vibrator installed on the outer wall of the conical bottom of the storage tank 2, with a vibration frequency of 25Hz and an amplitude of 2mm. The level sensor 4 is a radar level gauge installed at the top center of the storage tank 2, with a measurement range of 0 to 2m and an accuracy of ±3mm. The level sensor 4 is electrically connected to the control mechanism 19.

[0035] In other embodiments, the volume of the storage tank 2 can be 0.3 cubic meters, 0.8 cubic meters, and 1.0 cubic meters, as long as it meets the actual production batch requirements; the wall thickness can be 3 mm, 5 mm, and 6 mm, as long as it meets the pressure bearing and rigidity requirements; the surface roughness Ra can be 0.2 μm, 0.35 μm, and 0.4 μm, as long as it meets the requirement of powder non-adhesion. If the surface roughness Ra is greater than 0.4 μm, it will lead to increased adhesion between the powder and the tank wall, forming clumping on the wall, causing distortion of the storage quantity measurement and powder deterioration.

[0036] In this embodiment, the weighing and measuring mechanism includes a weighing sensor 5, a weighing hopper 6, and a discharge valve 7. The weighing sensor 5 is an electromagnetic force-compensated weighing sensor with a range of 50kg, an accuracy class of C3, a graduation value of 0.05g, and three of them, evenly distributed at 120° below the weighing hopper 6. The weighing hopper 6 adopts a conical design, with a volume of 30L, a cone angle of 60°, and is made of 316L stainless steel with an electropolished inner wall. The discharge valve 7 is a pneumatic butterfly valve with a diameter of DN100 and an opening time of no more than 2s.

[0037] In other embodiments, the weighing sensor 5 can have a range of 20kg, 100kg, and 200kg, as long as it meets the actual measurement range requirements; the graduation value can be 0.02g, 0.08g, and 0.1g, as long as it meets the feeding accuracy requirements. If the graduation value is greater than 0.1g, it will cause the measurement deviation of the trace toxic powder to exceed the safe allowable range; the cone angle of the metering hopper 6 can be 55°, 65°, and 70°, as long as it meets the requirement of smooth powder flow. If the cone angle is less than 55°, it will cause the powder to accumulate on the hopper wall and form a dead angle. If the cone angle is greater than 70°, it will cause the metering hopper to be too tall and occupy too much space.

[0038] In this embodiment, the screw conveying mechanism includes a variable frequency motor 8, a screw shaft 9, and a sealing housing 10; the variable frequency motor 8 has a power of 1.5kW and a speed range of 0 to 150rpm; the screw shaft 9 adopts a variable pitch design, with a screw pitch of 120mm at the feed end and 80mm at the discharge end, a screw diameter of 100mm, and the screw blades are made of polytetrafluoroethylene-coated stainless steel substrate; the connection between the sealing housing 10 and the feeding tower body 1 adopts an air-filled sealing structure, the sealing gas source is nitrogen, and the filling pressure is 0.02MPa higher than the pressure inside the tower.

[0039] In other embodiments, the power of the variable frequency motor 8 can be 0.75kW, 2.2kW, and 3.0kW, as long as it meets the conveying torque requirements; the feed end pitch can be 100mm, 110mm, and 140mm, and the discharge end pitch can be 60mm, 70mm, and 90mm, as long as the feed end pitch is 1.2 to 1.8 times the discharge end pitch. If the ratio is less than 1.2, it will cause the feed end to be too densely packed, increasing the starting torque; if the ratio is greater than 1.8, it will cause the discharge end to be too loose, resulting in powder backflow.

[0040] In this embodiment, the inert gas protection mechanism includes an inert gas inlet pipe 11, a flow regulating valve 12, and a pressure sensor 13. The inert gas inlet pipe 11 is made of 316L stainless steel seamless pipe with a nominal diameter of DN50, and is connected to the side wall and bottom of the feeding tower body 1. The flow regulating valve 12 is an electric regulating valve, installed on the inert gas inlet pipe 11, with an adjustment accuracy of ±1% and a response time of no more than 3s. The pressure sensor 13 is a diffused silicon pressure sensor with a range of 0 to 0.6MPa and an accuracy of ±0.25%FS, and is installed at the bottom of the feeding tower body 1.

[0041] In other embodiments, the nominal diameter of the inert gas inlet pipe 11 can be DN25, DN40, or DN80, as long as it meets the maximum inert gas flow rate requirement; the adjustment accuracy of the flow regulating valve 12 can be ±2% or ±0.5%, as long as it meets the flow control accuracy requirement.

[0042] In this embodiment, the exhaust gas treatment mechanism includes an exhaust gas treatment tank 15, an inlet pipe 16, and an outlet pipe 17. The exhaust gas treatment tank 15 is a packed absorption tower with a volume of 0.1 cubic meters, filled with activated carbon and alkaline absorbent. One end of the inlet pipe 16 is connected to the exhaust port at the top of the feeding tower 1, and the other end extends to the bottom of the exhaust gas treatment tank 15. The outlet pipe 17 is located at the top of the exhaust gas treatment tank 15 and discharges the treated gas into the atmosphere.

[0043] In other embodiments, the volume of the exhaust gas treatment tank 15 can be 0.05 cubic meters, 0.08 cubic meters, and 0.2 cubic meters, as long as it meets the exhaust gas treatment load requirements.

[0044] In this embodiment, the sealing and isolation mechanism includes a sealing and isolation door 18 and an inflatable sealing ring; the sealing and isolation door 18 is a pneumatic quick-opening blind plate with an opening time of no more than 5 seconds; the inflatable sealing ring is a silicone rubber inflatable sealing ring with an inflation pressure of 0.3 MPa.

[0045] In other embodiments, the opening time of the sealed isolation door 18 can be 3s, 4s, or 6s, as long as it meets the requirement of rapid isolation.

[0046] In this embodiment, the control mechanism 19 is an industrial PLC controller, using the Siemens S7-1500 series, including a CPU module, an analog input module, an analog output module, and a communication module; the CPU module has a built-in powder feeding accuracy control algorithm and an inert gas protection safety algorithm; the analog input module is electrically connected to the weighing sensor 5, the oxygen concentration sensor 14, the pressure sensor 13, and the material level sensor 4 respectively; the analog output module is electrically connected to the variable frequency motor 8, the flow regulating valve 12, and the unloading valve 7 respectively.

[0047] Please see Figure 2 As shown, this is a schematic diagram of the control mechanism, which includes: The powder feeding accuracy control module is used to generate a basic feeding scheme based on powder physical property parameters, to perform a first verification of the generation process of the basic feeding scheme based on real-time weighing residual data to obtain a verified feeding scheme, and to perform a second optimization of the first verification process based on environmental disturbance parameters to obtain a target feeding scheme. An inert gas protection safety module is used to generate a basic protection scheme based on the reactor pressure parameters, to make a first correction to the generation process of the basic protection scheme based on real-time oxygen concentration monitoring data to obtain a corrected protection scheme, and to make a second compensation to the first correction process based on the feeding disturbance feedback parameters to obtain a target protection scheme. The inert gas protection safety module is connected to the powder feeding accuracy control module. The collaborative execution module is used to control the rotational speed of the screw conveyor according to the target feeding scheme and to control the flow rate of the inert gas protection mechanism according to the target protection scheme. The collaborative execution module is connected to the inert gas protection safety module.

[0048] Please see Figure 3 The diagram shown is a structural diagram of a powder feeding accuracy control module, which includes: The basic feeding unit is used to generate a basic feeding plan based on the powder's physical properties. The weighing calibration unit is used to calibrate the generation process of the basic feeding scheme based on real-time weighing residual data to obtain the calibrated feeding scheme. The weighing calibration unit is connected to the basic feeding unit. The disturbance optimization unit is used to perform secondary optimization on the primary calibration process based on environmental disturbance parameters to obtain the target feeding scheme. The disturbance optimization unit is connected to the weighing calibration unit.

[0049] Specifically, the generation of a basic feeding scheme based on powder physical property parameters includes: The powder physical properties parameters are obtained, including powder particle size distribution d, powder moisture content h, powder bulk density ρ, and powder angle of repose θ. The powder particle size distribution d refers to the range of powder particle diameter distribution measured by a laser particle size analyzer, in micrometers. In this embodiment, d = 50 μm. The powder particle size distribution d characterizes the fineness of the powder particles; the smaller the particle size, the larger the specific surface area of ​​the powder, the stronger the surface adsorption force, and the worse the flowability. The powder moisture content h refers to the powder water content measured by a halogen moisture analyzer, in percentages. In this embodiment, h = 2%. The powder moisture content h characterizes the thickness of the adsorbed water film on the powder surface; the higher the moisture content, the thicker the powder surface water film. The greater the interparticle liquid bridging force, the worse the flowability. The powder bulk density ρ refers to the unit volume mass of the powder in its natural stacked state, measured by a loose packing density meter, in kilograms per cubic meter. In this embodiment, ρ = 800 kg / m³. The powder bulk density ρ characterizes the compactness of the powder. The greater the bulk density, the greater the powder mass per unit volume, and the greater the load on the screw conveyor. The powder angle of repose θ refers to the angle between the inclined plane of the powder's natural stacking cone and the horizontal plane, measured by a powder flowability tester, in degrees. In this embodiment, θ = 40°. The powder angle of repose θ characterizes the internal friction characteristics of the powder. The larger the angle of repose, the greater the friction between powder particles, and the worse the flowability.

[0050] The powder flow index Φ is calculated based on the powder particle size distribution d, the powder humidity h, the powder bulk density ρ, and the powder angle of repose θ. The formula is Φ = ξ × d / d0 + δ × h / h0 + ε × ρ / ρ0 + ζ × θ / θ0, where d0 is the reference particle size, h0 is the reference humidity, ρ0 is the reference bulk density, θ0 is the reference angle of repose, ξ is the first property weight, δ is the second property weight, ε is the third property weight, and ζ is the fourth property weight. The reference particle size d0 is a reference value used as a normalization benchmark when calculating the powder flow index, and is set to d0 = 100 μm. This reference particle size corresponds to a typical value for medium-sized powders and serves as the normalization benchmark. The relative proportional relationship of powder flowability is established; the reference humidity h0 refers to the reference value used as the normalization reference when calculating the powder flowability index, with a value of h0=5%, and the reference humidity corresponds to the typical moisture content of conventionally dried powder; the reference bulk density ρ0 refers to the reference value used as the normalization reference when calculating the powder flowability index, with a value of ρ0=1000kg / m3, and the reference bulk density corresponds to the typical bulk density of conventional powder; the reference angle of repose θ0 refers to the reference value used as the normalization reference when calculating the powder flowability index, with a value of θ0=45°, and the reference angle of repose corresponds to the typical angle of repose of powder with medium flowability; the first property weight ξ refers to the weight of the powder flowability index. The weighting coefficient assigned to powder particle size distribution when calculating the powder flow index is ξ=0.3. The rationale for this first property weight is that particle size distribution accounts for 30% to 35% of the powder flowability; smaller particle size leads to increased specific surface area and surface energy, resulting in stronger van der Waals forces between particles, hence the weight of 0.3. The second property weight δ refers to the weighting coefficient assigned to powder moisture when calculating the powder flow index, with a value of δ=0.35. The rationale for this second property weight is that moisture accounts for 35% to 40% of the powder flowability; increased moisture leads to a significant increase in liquid bridging forces between particles, which is the dominant factor in flowability degradation, hence the highest weight of 0.35. The third property weight ε refers to the weighting coefficient assigned to the powder bulk density when calculating the powder flow index, with a value of ε=0.15. The reason for this third property weight is that the bulk density accounts for 10% to 15% of the powder flowability. The bulk density mainly affects the conveying load rather than the flowability itself, hence the low weight of 0.15. The fourth property weight ζ refers to the weighting coefficient assigned to the powder angle of repose when calculating the powder flow index, with a value of ζ=0.2. The reason for this fourth property weight is that the angle of repose accounts for 20% to 25% of the powder flowability. The angle of repose directly reflects the internal friction characteristics of the powder, hence the weight of 0.2 complements the first property weight.

[0051] In this embodiment, substituting d=50μm, h=2%, ρ=800kg / m3, and θ=40°, we calculate Φ=0.3×50 / 100+0.35×2 / 5+0.15×800 / 1000+0.2×40 / 45=0.15+0.14+0.12+0.178=0.588.

[0052] The basic screw speed n0 is calculated based on the powder flow index Φ, and n0 is set as n0 = nmax × (1 - Φ / Φmax), where nmax is the maximum allowable screw speed and Φmax is the maximum powder flow index. The maximum allowable screw speed nmax refers to the highest speed of the screw shaft without excessive powder compaction or mechanical damage to the equipment, and is set to nmax = 120 rpm. The maximum allowable screw speed corresponds to 80% of the rated speed of the strain frequency motor, with a 20% margin to accommodate the need for speed reduction. The maximum powder flow index Φmax refers to the theoretical upper limit of the powder flow index, and is set to Φmax = 2.0. The maximum powder flow index corresponds to the upper limit of the normalized index for powders with extremely poor flowability (ultrafine, high moisture, large angle of repose).

[0053] In this embodiment, n0 = 120 × (1 - 0.588 / 2.0) = 120 × 0.706 = 84.7 rpm, which is rounded down to 85 rpm.

[0054] The basic feed flow rate q0 is calculated based on the basic screw rotation speed n0, and q0 is set as k × n0 × ρ × A, where k is the screw conveying coefficient and A is the cross-sectional area of ​​the screw blade. The screw conveying coefficient k is a dimensionless coefficient characterizing the screw conveying efficiency, with a value of k = 0.85. The screw conveying coefficient takes into account the friction loss between the powder and the screw blade and the shell, and a value of 0.85 corresponds to the low friction condition of the PTFE-coated blade. The cross-sectional area A of the screw blade refers to the projected area of ​​the screw blade perpendicular to the conveying direction, in square meters. In this embodiment, the screw diameter is 100 mm, the screw pitch is 100 mm, and A = π × (0.1)² / 4 = 0.00785 m².

[0055] In this embodiment, q0 = 0.85 × 85 × 800 × 0.00785 = 452.5 kg / h.

[0056] In other embodiments, the powder particle size distribution d can be 30μm, 80μm, and 150μm; the powder moisture content h can be 0.5%, 3%, and 5%; the powder bulk density ρ can be 500kg / m3, 1000kg / m3, and 1200kg / m3; and the powder angle of repose θ can be 30°, 35°, and 50°, as long as it meets the actual powder physical property parameter range. The first physical property weight ξ can be 0.25, 0.3, and 0.35; the second physical property weight δ can be 0.3, 0.35, and 0.4; the third physical property weight ε can be 0.1, 0.15, and 0.2; and the fourth physical property weight ζ can be 0.15, 0.2, and 0.25, as long as ξ+δ+ε+ζ=1. If the sum of the weights is not 1, it will cause the powder flow index calculation to be distorted, and the basic screw speed setting will deviate from the actual flowability requirements.

[0057] Specifically, the step of verifying the generation process of the basic feeding scheme based on real-time weighing residual data to obtain the verified feeding scheme includes: The real-time weighing residual data is acquired, which includes instantaneous weighing deviation Δm and cumulative weighing deviation Σm. The instantaneous weighing deviation Δm refers to the difference between the measured value of the weighing sensor at the current sampling time and the set feeding amount, in grams. In this embodiment, the sampling period is 0.5s, and Δm is acquired in real time by the weighing sensor 5. The cumulative weighing deviation Σm refers to the algebraic sum of all instantaneous deviations from the start of feeding to the current time, in grams, and Σm is calculated by the integration module of the control mechanism 19.

[0058] The weighing deviation index Ψ is calculated based on the instantaneous weighing deviation Δm, the cumulative weighing deviation Σm, the first deviation weight ω1, and the second deviation weight ω2. Ψ is set as ω1×|Δm| / Δmmax+ω2×|Σm| / Σmmax, where Δmmax is the maximum permissible instantaneous deviation, and Σmmax is the maximum permissible cumulative deviation. The maximum permissible instantaneous deviation Δmmax refers to the maximum permissible weighing deviation within a single sampling period, with a value of Δmmax=50g. This maximum permissible instantaneous deviation corresponds to a 0.5% instantaneous fluctuation tolerance when the feed amount is set to 10kg. The maximum permissible cumulative deviation Σmmax refers to the maximum permissible cumulative deviation within the entire feeding period, with a value of Σmmax=100g. The deviation corresponds to a 1% cumulative error tolerance when the feed rate is set to 10kg. The first deviation weight ω1 is the weight coefficient assigned to the instantaneous weighing deviation when calculating the weighing deviation index, with a value of ω1=0.6. The reason for the first deviation weight is that the instantaneous deviation reflects the fluctuation of the feed flow rate at the current moment, and its immediate impact on the feed accuracy accounts for more than 60%, so a higher weight is assigned to prioritize the suppression of instantaneous overshoot. The second deviation weight ω2 is the weight coefficient assigned to the cumulative weighing deviation when calculating the weighing deviation index, with a value of ω2=0.4. The reason for the second deviation weight is that the cumulative deviation reflects the systematic drift over a long period of operation, and its impact on the final feed accuracy accounts for 30% to 40%, so a weight of 0.4 is assigned to complement the first deviation weight.

[0059] The weighing deviation index Ψ is compared with the preset deviation index Ψ0. Based on the comparison result, the feeding accuracy is judged, and based on the judgment result, the basic feeding scheme is calibrated once, wherein: When Ψ≤Ψ0, the feeding accuracy is determined to be normal, and no calibration is performed on the basic feeding scheme. When Ψ > Ψ0, the feeding accuracy is determined to be abnormal. The basic feeding scheme is then calibrated to obtain the calibrated screw speed n1. n1 is set as n0 × [1 - χ × (Ψ - Ψ0) / Ψmax], where χ is the speed correction coefficient and Ψmax is the maximum weighing deviation index. The preset deviation index Ψ0 is the critical threshold for determining whether the feeding accuracy has entered the abnormal region, with a value of Ψ0 = 0.5. The preset deviation index is a dimensionless normalized threshold. When Ψ = 0.5, the instantaneous deviation reaches 50% of the maximum allowable value, and the cumulative deviation reaches 50% of the maximum allowable value. Exceeding this value indicates that the feeding flow rate has significantly deviated from the set value. The speed correction coefficient χ is the control factor during the calibration process. The adjustment parameter for reducing the screw speed is set to χ=0.5. The reason for setting the speed correction coefficient is as follows: According to the conservative control strategy, it is necessary to ensure that the screw speed n1 ≥ 0.5n0 after calibration under the maximum deviation condition. Substituting χ=0.5 and Ψmax=2.0, when Ψ=Ψmax, n1=n0×[1-0.5×(2.0-0.5) / 2.0]=0.625n0, which effectively suppresses overshoot and avoids complete shutdown leading to material feeding interruption. The maximum weighing deviation index Ψmax refers to the theoretical upper limit of the weighing deviation index, which is set to Ψmax=2.0. The maximum weighing deviation index corresponds to the superposition state where the instantaneous deviation and cumulative deviation reach the maximum allowable value at the same time under extreme conditions.

[0060] In this embodiment, assuming that at a certain moment Δm=30g and Σm=40g, then Ψ=0.6×30 / 50+0.4×40 / 100=0.36+0.16=0.52>Ψ0=0.5, the feeding accuracy is determined to be abnormal, and a calibration is performed, n1=85×[1-0.5×(0.52-0.5) / 2.0]=85×0.995=84.6rpm.

[0061] In other embodiments, the maximum permissible instantaneous deviation Δmmax can be 30g, 40g, and 60g, and the maximum permissible cumulative deviation Σmmax can be 80g, 120g, and 150g, as long as the actual feeding accuracy requirements are met; the first deviation weight ω1 can be 0.5, 0.55, and 0.65, and the second deviation weight ω2 can be 0.35, 0.4, and 0.45, as long as ω1+ω2=1 is satisfied; the preset deviation index Ψ0 can be 0.4, 0.45, and 0.6, as long as the actual working conditions require sensitivity to deviation. If Ψ0 is set too high, it will lead to a delayed calibration response; if Ψ0 is set too low, it will lead to frequent calibrations causing speed oscillations.

[0062] Specifically, the secondary optimization of the primary calibration process based on environmental disturbance parameters to obtain the target feeding scheme includes: The environmental disturbance parameters are acquired, including the rate of change of ambient temperature τ, the rate of change of ambient humidity φ, and the amplitude of vibration acceleration a. The rate of change of ambient temperature τ refers to the change in ambient temperature per unit time, in degrees Celsius per minute. In this embodiment, it is acquired in real time by a temperature sensor, and τ = 0.5℃ / min. The rate of change of ambient humidity φ refers to the change in relative humidity per unit time, in percentage per minute. In this embodiment, it is acquired in real time by a humidity sensor, and φ = 1% / min. The amplitude of vibration acceleration a refers to the peak value of vibration acceleration at the installation position of the weighing and measuring mechanism, in meters per second squared. In this embodiment, it is acquired in real time by an acceleration sensor, and a = 0.5 m / s².

[0063] The disturbance gain coefficient Γ is calculated based on the ambient temperature change rate τ, the ambient humidity change rate φ, the vibration acceleration amplitude a, the first disturbance weight α, the second disturbance weight β, and the third disturbance weight γ. Γ is set as α × |τ| / τmax + β × |φ| / φmax + γ × |a| / amax, where τmax is the maximum temperature change rate threshold, φmax is the maximum humidity change rate threshold, and amax is the maximum vibration acceleration threshold. The maximum temperature change rate threshold τmax refers to the maximum allowable rate of change of ambient temperature, with a value of τmax = 2℃ / min. This threshold corresponds to extreme temperature fluctuations during summer when the workshop air conditioning malfunctions or during winter when doors and windows are open. The maximum humidity change rate threshold φmax refers to the maximum allowable rate of change of ambient humidity, with a value of φmax = 5% / min. This threshold corresponds to extreme humidity fluctuations during the rainy season or when drying equipment starts and stops. The maximum vibration acceleration threshold amax refers to the maximum allowable ambient vibration acceleration of the weighing and measuring institution, with a value of amax = 2 m / s². The maximum vibration acceleration threshold corresponds to the extreme vibration when nearby equipment is running or vehicles pass by; the first disturbance weight α is the weighting coefficient assigned to the rate of change of ambient temperature when calculating the disturbance gain coefficient, and its value is α=0.4. The reason for the first disturbance weight is that temperature changes cause changes in the thickness of the water film adsorbed on the powder surface, which in turn affects the powder flowability, accounting for 35% to 45% of the impact on feeding accuracy, hence the weight of 0.4 is assigned; the second disturbance weight β is the weighting coefficient assigned to the rate of change of ambient humidity when calculating the disturbance gain coefficient, and its value is β=0. 35. The reason for the second disturbance weight is that humidity changes directly affect the powder moisture content, which is the direct cause of changes in flowability. It accounts for 30% to 40% of the impact on feeding accuracy, so it is assigned a weight of 0.35. The third disturbance weight γ refers to the weight coefficient assigned to the vibration acceleration amplitude when calculating the disturbance gain coefficient. The value is γ=0.25. The reason for the third disturbance weight is that vibration acceleration interferes with the stability of the weighing sensor signal, causing fluctuations in the weighing reading. It accounts for 20% to 30% of the impact on feeding accuracy, so it is assigned a weight of 0.25.

[0064] The perturbation gain coefficient Γ is compared with the preset gain coefficient Γ0. Based on the comparison result, the perturbation coupling state is judged, and the first calibration process is optimized a second time based on the judgment result, wherein: When Γ≤Γ0, the disturbance coupling state is determined to be stable coupling, and no secondary optimization is performed on the first calibration process; When Γ > Γ0, the disturbance coupling state is determined to be strong coupling. A secondary optimization is performed on the first calibration process to obtain the target screw speed n2. n2 is set as n1 × [1 - η × (Γ - Γ0) / Γmax], where η is the coupling suppression coefficient and Γmax is the maximum disturbance gain. The preset gain coefficient Γ0 refers to the critical threshold for determining whether the disturbance coupling state has entered the strong coupling region, with a value of Γ0 = 0.5. The preset gain coefficient is a dimensionless normalized threshold. When Γ = 0.5, it corresponds to a superposition state where the temperature change rate reaches 50% of the maximum threshold and the humidity change rate reaches 50% of the maximum threshold. Exceeding this value indicates that environmental disturbances have a significant coupling effect on the feeding accuracy. The coupling suppression coefficient η refers to the value of the maximum disturbance speed n2 obtained in the second calibration process. The adjustment parameter for controlling the reduction of the screw speed during the optimization process is set to η=0.4. The reason for the value of the coupling suppression coefficient is as follows: According to the conservative control strategy, it is necessary to ensure that the target screw speed n2≥0.6n1 under the maximum disturbance condition. Substituting η=0.4 and Γmax=2.0, when Γ=Γmax, n2=n1×[1-0.4×(2.0-0.5) / 2.0]=0.7n1, which effectively suppresses environmental disturbances while retaining sufficient feed flow. The maximum disturbance gain Γmax refers to the theoretical upper limit of the disturbance gain coefficient, which is set to Γmax=2.0. The maximum disturbance gain corresponds to the superposition state where the temperature change rate, humidity change rate and vibration acceleration simultaneously reach the maximum threshold under extreme conditions.

[0065] In this embodiment, substituting τ=0.5℃ / min, φ=1% / min, and a=0.5m / s2, we calculate Γ=0.4×0.5 / 2+0.35×1 / 5+0.25×0.5 / 2=0.1+0.07+0.0625=0.2325≤Γ0=0.5, determining the disturbance coupling state as stable coupling, and not performing secondary optimization on the first calibration process, the target helical speed n2=n1=84.6rpm.

[0066] In other embodiments, the ambient temperature change rate τ can be 1℃ / min, 1.5℃ / min, and 2℃ / min; the ambient humidity change rate φ can be 2% / min, 3% / min, and 5% / min; the vibration acceleration amplitude a can be 1m / s², 1.5m / s², and 2m / s², as long as it meets the actual environmental disturbance range; the first disturbance weight α can be 0.35, 0.4, and 0.45; the second disturbance weight β can be 0.3, 0.35, and 0.4; the third disturbance weight γ can be 0.2, 0.25, and 0.3, as long as α+β+γ=1; the preset gain coefficient Γ0 can be 0.4, 0.45, and 0.6, as long as it meets the disturbance sensitivity requirements of the actual working conditions.

[0067] Please see Figure 4The diagram shown is a structural schematic of an inert gas protection safety module, which includes: The basic protection unit is used to generate a basic protection scheme based on the pressure parameters of the reactor. An oxygen concentration correction unit is used to correct the generation process of the basic protection scheme based on real-time oxygen concentration monitoring data to obtain a corrected protection scheme. The oxygen concentration correction unit is connected to the basic protection unit. The disturbance compensation unit is used to perform secondary compensation on the primary correction process based on the feeding disturbance feedback parameters to obtain the target protection scheme. The disturbance compensation unit is connected to the oxygen concentration correction unit.

[0068] Specifically, the generation of a basic protection scheme based on the reactor pressure parameters includes: The pressure parameters of the reactor are obtained, including the initial pressure p, the volume v, and the temperature t. The initial pressure p refers to the absolute pressure inside the reactor before feeding, in Pascals; in this embodiment, p = 101325 Pa. The volume v refers to the effective gas phase space volume of the reactor, in cubic meters; in this embodiment, v = 2 m³. The temperature t refers to the absolute temperature inside the reactor, in Kelvin; in this embodiment, t = 298 K.

[0069] The required amount of inert gas g0 is calculated based on the initial pressure p of the reactor, the volume v of the reactor, the temperature t of the reactor, and the gas state constant r. The formula is g0 = p × v / (r × t), where r is the gas state constant and its value is r = 8.314 J / (mol·K).

[0070] In this embodiment, g0 = 101325 × 2 / (8.314 × 298) = 81.8 mol, which is converted to a volume of 81.8 × 22.4 / 1000 = 1.83 m3 under standard conditions.

[0071] The basic inert gas flow rate f0 is calculated based on the inert gas demand g0, and f0 is set as f0 = g0 / tc, where tc is the feeding cycle duration. The feeding cycle duration tc refers to the theoretical time required to complete a single feeding operation, in seconds. In this embodiment, the feeding amount is set to 10 kg, the basic feeding flow rate q0 = 452.5 kg / h, and tc = 10 / 452.5 × 3600 = 79.6 s, which is rounded up to 80 s.

[0072] In this embodiment, f0 = 1.83 / 80 × 3600 = 82.4 m3 / h.

[0073] The basic inert gas pressure p0 is calculated based on the basic inert gas flow rate f0, and p0 is set as p0 = μ × f0 / (π × d² / 4), where μ is the pipeline resistance coefficient and d is the diameter of the inert gas pipeline. The pipeline resistance coefficient μ is a dimensionless coefficient characterizing the flow resistance loss of the inert gas in the pipeline, and its value is μ = 0.02. The pipeline resistance coefficient corresponds to the friction loss of a 316L stainless steel smooth pipeline. The inert gas pipeline diameter d is the inner diameter of the inert gas inlet pipe, in meters. In this embodiment, d = 0.05m.

[0074] In this embodiment, p0 = 0.02 × 82.4 / (π × 0.052 / 4) = 0.02 × 82.4 / 0.00196 = 0.84 MPa.

[0075] In other embodiments, the initial pressure p of the reactor can be 80000Pa, 120000Pa, and 150000Pa, the reactor volume v can be 1m3, 3m3, and 5m3, and the reactor temperature t can be 273K, 303K, and 323K, as long as it meets the actual operating conditions of the reactor.

[0076] Specifically, the process of generating the basic protection scheme based on real-time oxygen concentration monitoring data is modified to obtain the modified protection scheme, including: The real-time oxygen concentration monitoring data is acquired, including the current oxygen concentration c and the oxygen concentration change rate dc. The current oxygen concentration c refers to the volume fraction of oxygen in the reactor measured by the oxygen concentration sensor 14, in percentage form. In this embodiment, c = 0.5%. The oxygen concentration change rate dc refers to the change in oxygen concentration per unit time, in percentage form per minute. In this embodiment, dc = 0.1% / min. The oxygen concentration sensor 14 is an electrochemical oxygen sensor with a range of 0 to 25% and an accuracy of ±0.1%FS, and is installed at the top of the feeding tower 1.

[0077] The oxygen concentration correction coefficient Ω is calculated based on the current oxygen concentration c, the oxygen concentration change rate dc, the first oxygen concentration weight λ1, and the second oxygen concentration weight λ2. The formula is Ω = λ1 × c / cmax + λ2 × |dc| / dcmax, where cmax is the maximum allowable oxygen concentration and dcmax is the maximum allowable oxygen concentration change rate. The maximum allowable oxygen concentration cmax refers to the highest oxygen volume fraction allowed in the reactor for the safe feeding of toxic powder, and is set to cmax = 2%. This maximum allowable oxygen concentration corresponds to the lower explosive limit safety margin for most metal powders and organic toxic powders. The maximum allowable oxygen concentration change rate dcmax refers to the maximum allowable rate of increase in oxygen concentration, and is set to dcmax = 0.5% / min. The maximum permissible rate of change of oxygen concentration corresponds to the emergency response threshold when the seal suddenly fails. The first oxygen concentration weight λ1 is the weight coefficient assigned to the current oxygen concentration when calculating the oxygen concentration correction coefficient, with a value of λ1=0.6. The reason for assigning the first oxygen concentration weight is that the current oxygen concentration directly reflects the overall quality of the inert atmosphere and accounts for more than 60% of the determination of the safe state, so it is given a high weight. The second oxygen concentration weight λ2 is the weight coefficient assigned to the rate of change of oxygen concentration when calculating the oxygen concentration correction coefficient, with a value of λ2=0.4. The reason for assigning the second oxygen concentration weight is that the rate of change of oxygen concentration reflects the urgency of the seal leakage and accounts for 30% to 40% of the impact on the safety response speed, so it is given a weight of 0.4 to complement the first oxygen concentration weight.

[0078] The oxygen concentration correction coefficient Ω is compared with the preset correction coefficient Ω0. The sealing status is judged based on the comparison result, and the basic protection scheme is modified once based on the judgment result, wherein: When Ω≤Ω0, the sealing condition is determined to be good, and no modification is made to the basic protection scheme. When Ω > Ω0, the sealing state is determined to be at risk of leakage. The basic protection scheme is then modified to obtain the modified inert gas flow rate f1. f1 is set as f0 × [1 + σ × (Ω - Ω0) / Ωmax], where σ is the flow rate correction coefficient and Ωmax is the maximum oxygen concentration correction coefficient. The preset correction coefficient Ω0 refers to the critical threshold for determining whether the sealing state has entered the leakage risk zone, with a value of Ω0 = 0.5. This preset correction coefficient is a dimensionless normalized threshold. When Ω = 0.5, the oxygen concentration reaches 50% of the maximum allowable value, and the rate of change of oxygen concentration reaches 50% of the maximum allowable value. Exceeding this value indicates that the oxygen concentration is approaching the safety boundary. The flow rate correction coefficient σ refers to the control... The adjustment parameter for the inert gas flow rate increase is set to σ=1.0. The reason for the value of the flow rate correction coefficient is as follows: According to the safety priority strategy, the inert gas flow rate needs to be increased to twice the basic flow rate under the maximum oxygen concentration condition. Substituting σ=1.0 and Ωmax=2.0, when Ω=Ωmax, f1=f0×[1+1.0×(2.0-0.5) / 2.0]=1.75f0, which can quickly dilute oxygen and avoid excessive flow causing overpressure in the reactor. The maximum oxygen concentration correction coefficient Ωmax refers to the theoretical upper limit of the oxygen concentration correction coefficient, which is set to Ωmax=2.0. The maximum oxygen concentration correction coefficient corresponds to the superposition state where the oxygen concentration and the rate of change of oxygen concentration simultaneously reach the maximum allowable value under extreme conditions.

[0079] In this embodiment, substituting c=0.5% and dc=0.1% / min, we calculate Ω=0.6×0.5 / 2+0.4×0.1 / 0.5=0.15+0.08=0.23≤Ω0=0.5, and determine that the sealing condition is good. No modification is made to the basic protection scheme. After the modification, the inert gas flow rate f1=f0=82.4m3 / h.

[0080] In other embodiments, the maximum allowable oxygen concentration cmax can be 1%, 1.5%, and 3%, as long as it meets the safety oxygen concentration limit for the specific toxic powder. If cmax is set too high, it will lead to an explosion risk; if cmax is set too low, it will lead to excessive consumption of inert gas. The maximum allowable oxygen concentration change rate dcmax can be 0.3% / min, 0.4% / min, and 0.6% / min, as long as it meets the actual sealing response requirements. The first oxygen concentration weight λ1 can be 0.55, 0.6, and 0.65, and the second oxygen concentration weight λ2 can be 0.35, 0.4, and 0.45, as long as λ1+λ2=1 is satisfied.

[0081] Specifically, the secondary compensation of the first correction process based on the material feeding disturbance feedback parameters to obtain the target protection scheme includes: The feeding disturbance feedback parameters are acquired, including the instantaneous feeding flow fluctuation δq and the feeding port pressure pulsation δp. The instantaneous feeding flow fluctuation δq refers to the change in feeding flow rate per unit time, in kilograms per hour per minute. In this embodiment, it is obtained through differential calculation by the weighing sensor 5, and δq = 50 kg / h / min. The feeding port pressure pulsation δp refers to the fluctuation amplitude of the inert gas pressure at the feeding port, in Pascals. In this embodiment, it is obtained through the pressure sensor 13, and δp = 500 Pa.

[0082] The feeding disturbance index Y is calculated based on the instantaneous flow rate fluctuation δq, the pressure pulsation at the feeding port δp, the first disturbance weight κ1, and the second disturbance weight κ2. Y is set as Y = κ1 × |δq| / δqmax + κ2 × |δp| / δpmax, where δqmax is the maximum allowable flow rate fluctuation and δpmax is the maximum allowable pressure pulsation. The maximum allowable flow rate fluctuation δqmax refers to the maximum allowable flow rate change rate during a single feeding process, with a value of δqmax = 200 kg / h / min. This maximum allowable flow rate fluctuation corresponds to the extreme operating conditions when the screw conveyor accelerates from rest to full speed or undergoes emergency braking. The maximum allowable pressure pulsation δpmax refers to the maximum allowable inert gas pressure fluctuation at the feeding port, with a value of δpmax = 2000 Pa. The maximum permissible pressure pulsation corresponds to the pressure impact when the sealing isolation door of the feeding port is opened; the first disturbance weight κ1 refers to the weight coefficient assigned to the instantaneous flow fluctuation of the feeding when calculating the feeding disturbance index, with a value of κ1=0.55. The reason for the first disturbance weight is that the flow fluctuation causes a sudden change in powder momentum, forming a local negative pressure suction effect, which contributes 50% to 60% to the destruction of the inert atmosphere, so a weight of 0.55 is assigned; the second disturbance weight κ2 refers to the weight coefficient assigned to the pressure pulsation of the feeding port when calculating the feeding disturbance index, with a value of κ2=0.45. The reason for the second disturbance weight is that the pressure pulsation directly reflects the degree of damage to the inert gas protective layer, which accounts for 40% to 50% of the determination of the safety status, so a weight of 0.45 is assigned to complement the first disturbance weight.

[0083] The feeding disturbance index Y is compared with the preset disturbance index Y0. Based on the comparison result, the disturbance risk status is judged, and based on the judgment result, a second compensation is performed on the first correction process, wherein: When Y≤Y0, the disturbance risk status is determined to be controllable, and no secondary compensation is performed on the first correction process. When Y > Y0, the disturbance risk state is determined to be high-risk. A second compensation is performed on the first correction process to obtain the target inert gas flow rate f2. f2 is set as f1 × [1 + ρ × (Y - Y0) / Ymax], where ρ is the compensation gain coefficient and Ymax is the maximum feed disturbance index. The preset disturbance index Y0 refers to the critical threshold for determining whether the disturbance risk state has entered the high-risk area, with a value of Y0 = 0.5. The preset disturbance index is a dimensionless normalized threshold. When Y = 0.5, the flow rate fluctuation reaches 50% of the maximum allowable value, and the pressure pulsation reaches 50% of the maximum allowable value. Exceeding this value indicates that the feed disturbance has significantly damaged the inert atmosphere. The compensation gain coefficient ρ refers to the value of the inert gas flow rate during the second compensation process. The adjustment parameter for controlling the increase in inert gas flow rate is set to ρ=0.8. The reason for the value of the compensation gain coefficient is as follows: According to the safety priority strategy, the inert gas flow rate needs to be increased to 1.6 times the corrected flow rate under the maximum disturbance condition. Substituting ρ=0.8 and Ymax=2.0, when Y=Ymax, f2=f1×[1+0.8×(2.0-0.5) / 2.0]=1.6f1, which can quickly compensate for the disturbance damage and avoid the reactor overpressure caused by excessive flow. The maximum feeding disturbance index Ymax refers to the theoretical upper limit of the feeding disturbance index, which is set to Ymax=2.0. The maximum feeding disturbance index corresponds to the superposition state of flow fluctuation and pressure pulsation reaching the maximum allowable value at the same time under extreme conditions.

[0084] In this embodiment, substituting δq=50kg / h / min and δp=500Pa, we calculate Y=0.55×50 / 200+0.45×500 / 2000=0.1375+0.1125=0.25≤Y0=0.5, and determine that the disturbance risk is controllable. No secondary compensation is performed in the first correction process, and the target inert gas flow rate is f2=f1=82.4m3 / h.

[0085] In other embodiments, the maximum allowable flow rate fluctuation δqmax can be 150 kg / h / min, 250 kg / h / min, and 300 kg / h / min, and the maximum allowable pressure pulsation δpmax can be 1500 Pa, 2500 Pa, and 3000 Pa, as long as it meets the actual feeding disturbance range; the first disturbance weight κ1 can be 0.5, 0.55, and 0.6, and the second disturbance weight κ2 can be 0.4, 0.45, and 0.5, as long as κ1+κ2=1; the preset disturbance index Y0 can be 0.4, 0.45, and 0.6, as long as it meets the actual working condition's disturbance sensitivity requirements.

[0086] In this embodiment, the collaborative execution module controls the rotational speed of the screw conveyor according to the target feeding scheme and controls the flow rate of the inert gas protection mechanism according to the target protection scheme, including: The target spiral speed n2 is output to the inverter of the variable frequency motor 8 to control the spiral shaft 9 to run at the target spiral speed n2; The target inert gas flow rate f2 is output to the electric actuator of the flow regulating valve 12 to control the opening of the flow regulating valve 12 so that the inert gas flow rate reaches f2; The target inert gas flow rate f2 is compared with the target spiral rotation speed n2. When f2 / f0 > 1.5 and n2 / n0 < 0.7, it is determined to be an extreme working condition. An alarm signal is output to the audible and visual alarm of the control mechanism 19 to prompt the operator to check the sealing status and powder properties.

[0087] Specifically, the collaborative comparison refers to cross-verifying the output of the inert gas protection safety module with the output of the powder feeding accuracy control module. When the protective gas flow rate increases significantly while the feeding speed decreases significantly, it indicates that there may be serious sealing leakage or a sharp deterioration in powder flowability, requiring manual intervention for investigation.

[0088] The working process of this embodiment is as follows: When the equipment is started, the control mechanism 19 is initialized. The storage tank 2 of the powder storage mechanism stores the toxic powder to be added. The material level sensor 4 detects the amount of material stored and feeds it back to the control mechanism 19. The powder feeding accuracy control module of the control mechanism 19 acquires the powder physical property parameters, calculates the powder flow index Φ=0.588, generates a basic feeding scheme, with a basic screw speed n0=85rpm and a basic feeding flow rate q0=452.5kg / h; The inert gas protection safety module of the control mechanism 19 obtains the pressure parameters of the reactor, calculates the inert gas demand g0=81.8mol, generates a basic protection scheme, the basic inert gas flow rate f0=82.4m3 / h, and the basic inert gas pressure p0=0.84MPa. When the sealed isolation door 18 is opened, the inert gas protection mechanism fills the feeding tower 1 and the reactor 20 with nitrogen gas at a basic inert gas flow rate f0, and the oxygen concentration sensor 14 monitors the oxygen concentration in real time. When the oxygen concentration drops below 0.5%, the variable frequency motor 8 starts, and the screw shaft 9 runs at the basic screw speed n0, conveying the toxic powder in the metering hopper 6 to the feeding tower 1 via the screw conveyor mechanism, and then falling into the reaction vessel 20. The weighing sensor 5 detects the weight change of the measuring hopper 6 in real time, calculates the instantaneous weighing deviation Δm and the cumulative weighing deviation Σm, calculates the weighing deviation index Ψ, and when Ψ>Ψ0, performs a calibration on the basic screw speed n0 to obtain the calibrated screw speed n1. The temperature sensor, humidity sensor and acceleration sensor detect environmental disturbance parameters in real time, calculate the disturbance gain coefficient Γ, and when Γ>Γ0, perform secondary optimization on the calibrated helical speed n1 to obtain the target helical speed n2, which is then output to the variable frequency motor 8. The oxygen concentration sensor 14 detects the current oxygen concentration c and the oxygen concentration change rate dc in real time, calculates the oxygen concentration correction coefficient Ω, and corrects the basic inert gas flow rate f0 once when Ω > Ω0 to obtain the corrected inert gas flow rate f1. The weighing sensor 5 and the pressure sensor 13 detect the instantaneous flow fluctuation δq and the pressure pulsation δp at the feeding port in real time, calculate the feeding disturbance index Y, and when Y>Y0, perform secondary compensation on the corrected inert gas flow rate f1 to obtain the target inert gas flow rate f2, which is then output to the flow regulating valve 12. After feeding is completed, the variable frequency motor 8 stops, the unloading valve 7 closes, the sealing isolation door 18 closes, and the inert gas protection mechanism continues to maintain the inert atmosphere in the reactor 20 at the target inert gas flow rate f2. The exhaust gas treatment mechanism purifies the inert gas containing trace amounts of toxic powder through activated carbon and alkaline absorbent in the exhaust gas treatment tank 15, and then discharges it into the atmosphere through the exhaust pipe 17.

[0089] In this embodiment, the feeding accuracy reaches ±0.3%, the oxygen concentration is stable below 0.5%, the inert gas utilization rate is increased by more than 40%, the operating cost is reduced by 25% compared with the fixed flow supply method, and the feeding accuracy deviation is no greater than ±0.5% under the disturbance conditions of ambient temperature change ±5℃, humidity change ±10%, and vibration acceleration ±1m / s2.

[0090] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A precise feeding device for toxic powders based on inert gas protection, characterized in that, include: Feeding tower body, powder storage mechanism, weighing and metering mechanism, screw conveyor mechanism, inert gas protection mechanism, exhaust gas treatment mechanism, sealing and isolation mechanism and control mechanism; The powder storage mechanism is connected to the top of the feeding tower body; the weighing and metering mechanism is located below the powder storage mechanism and connected to the screw conveyor mechanism, which extends into the interior of the feeding tower body; the inert gas protection mechanism is connected to the side wall and bottom of the feeding tower body; the exhaust gas treatment mechanism is connected to the top of the feeding tower body; and the sealing and isolation mechanism is located at the feeding port of the feeding tower body; the control mechanism is electrically connected to the weighing and metering mechanism, the screw conveyor mechanism, the inert gas protection mechanism, and the exhaust gas treatment mechanism, respectively. The control mechanism includes: The powder feeding accuracy control module is used to generate a basic feeding scheme based on powder physical property parameters, to perform a first verification of the generation process of the basic feeding scheme based on real-time weighing residual data to obtain a verified feeding scheme, and to perform a second optimization of the first verification process based on environmental disturbance parameters to obtain a target feeding scheme. An inert gas protection safety module is used to generate a basic protection scheme based on the reactor pressure parameters, to make a first correction to the generation process of the basic protection scheme based on real-time oxygen concentration monitoring data to obtain a corrected protection scheme, and to make a second compensation to the first correction process based on the feeding disturbance feedback parameters to obtain a target protection scheme. The collaborative execution module is used to control the rotational speed of the screw conveyor according to the target feeding scheme and to control the flow rate of the inert gas protection mechanism according to the target protection scheme.

2. The precise feeding device for toxic powder based on inert gas protection according to claim 1, characterized in that, The process of generating a basic feeding scheme based on powder physical property parameters includes: The powder physical properties parameters are obtained, including powder particle size distribution d, powder moisture content h, powder bulk density ρ, and powder angle of repose θ. The powder flow index Φ is calculated based on the powder particle size distribution d, the powder humidity h, the powder bulk density ρ, and the powder angle of repose θ. Φ is defined as ξ×d / d0+δ×h / h0+ε×ρ / ρ0+ζ×θ / θ0, where d0 is the reference particle size, h0 is the reference humidity, ρ0 is the reference bulk density, θ0 is the reference angle of repose, ξ is the first property weight, δ is the second property weight, ε is the third property weight, and ζ is the fourth property weight. The basic screw speed n0 is calculated based on the powder flow index Φ, and n0 is set as n0 = nmax × (1 - Φ / Φmax), where nmax is the maximum allowable screw speed and Φmax is the maximum powder flow index. The basic feed flow rate q0 is calculated based on the basic screw rotation speed n0, and q0 is set as k×n0×ρ×A, where k is the screw conveying coefficient and A is the cross-sectional area of ​​the screw blade. The basic screw rotation speed n0 and the basic feeding flow rate q0 are output as the basic feeding scheme.

3. The precise feeding device for toxic powder based on inert gas protection according to claim 2, characterized in that, The process of generating the basic feeding scheme based on real-time weighing residual data is calibrated to obtain the calibrated feeding scheme, including: The real-time weighing residual data is acquired, and the real-time weighing residual data includes instantaneous weighing deviation Δm and cumulative weighing deviation Σm. The weighing deviation index Ψ is calculated based on the instantaneous weighing deviation Δm, the cumulative weighing deviation Σm, the first deviation weight ω1, and the second deviation weight ω2. Ψ is set as ω1×|Δm| / Δmmax+ω2×|Σm| / Σmmax, where Δmmax is the maximum permissible instantaneous deviation and Σmmax is the maximum permissible cumulative deviation. The weighing deviation index Ψ is compared with the preset deviation index Ψ0. Based on the comparison result, the feeding accuracy is judged, and based on the judgment result, the basic feeding scheme is calibrated once, wherein: When Ψ≤Ψ0, the feeding accuracy is determined to be normal, and no calibration is performed on the basic feeding scheme. When Ψ>Ψ0, the feeding accuracy is determined to be abnormal. The basic feeding scheme is then calibrated to obtain the calibrated screw speed n1. n1 is set as n0×[1-χ×(Ψ-Ψ0) / Ψmax], where χ is the speed correction coefficient and Ψmax is the maximum weighing deviation index. The calibrated screw speed n1 is then replaced in the basic feeding scheme to obtain the calibrated feeding scheme.

4. The precise feeding device for toxic powder based on inert gas protection according to claim 3, characterized in that, The second optimization of the primary calibration process based on environmental disturbance parameters to obtain the target feeding scheme includes: The environmental disturbance parameters are acquired, including the rate of change of ambient temperature τ, the rate of change of ambient humidity φ, and the amplitude of vibration acceleration a. The disturbance gain coefficient Γ is calculated based on the ambient temperature change rate τ, the ambient humidity change rate φ, the vibration acceleration amplitude a, the first disturbance weight α, the second disturbance weight β, and the third disturbance weight γ. Γ is set as α×|τ| / τmax+β×|φ| / φmax+γ×|a| / amax, where τmax is the maximum temperature change rate threshold, φmax is the maximum humidity change rate threshold, and amax is the maximum vibration acceleration threshold. The perturbation gain coefficient Γ is compared with the preset gain coefficient Γ0. Based on the comparison result, the perturbation coupling state is judged, and the first calibration process is optimized a second time based on the judgment result, wherein: When Γ≤Γ0, the disturbance coupling state is determined to be stable coupling, and no secondary optimization is performed on the first calibration process; When Γ>Γ0, the disturbance coupling state is determined to be strong coupling. The first calibration process is then optimized to obtain the target spiral speed n2. n2 is set to n1×[1-η×(Γ-Γ0) / Γmax], where η is the coupling suppression coefficient and Γmax is the maximum disturbance gain. The target spiral speed n2 is then replaced in the calibration feeding scheme to obtain the target feeding scheme.

5. The precise feeding device for toxic powder based on inert gas protection according to claim 1, characterized in that, The process of generating a basic protection scheme based on the reactor pressure parameters includes: The pressure parameters of the reactor are acquired, including the initial pressure p, the volume v, and the temperature t. The inert gas requirement g0 is calculated based on the initial pressure p of the reactor, the volume v of the reactor, the temperature t of the reactor, and the gas state constant r, and g0 is set as p × v / (r × t). The basic inert gas flow rate f0 is calculated based on the inert gas demand g0, and f0 is set as g0 / tc, where tc is the feeding cycle length. The basic inert gas pressure p0 is calculated based on the basic inert gas flow rate f0, and p0 is set as μ×f0 / (π×d2 / 4), where μ is the pipeline resistance coefficient and d is the diameter of the inert gas pipeline. The basic inert gas flow rate f0 and the basic inert gas pressure p0 are output as the basic protection scheme.

6. The precise feeding device for toxic powder based on inert gas protection according to claim 5, characterized in that, The process of generating the basic protection scheme based on real-time oxygen concentration monitoring data is modified to obtain the modified protection scheme, which includes: The real-time oxygen concentration monitoring data is acquired, including the current oxygen concentration c and the oxygen concentration change rate dc; The oxygen concentration correction coefficient Ω is calculated based on the current oxygen concentration c, the oxygen concentration change rate dc, the first oxygen concentration weight λ1, and the second oxygen concentration weight λ2. The formula is Ω = λ1 × c / cmax + λ2 × |dc| / dcmax, where cmax is the maximum allowable oxygen concentration and dcmax is the maximum allowable oxygen concentration change rate. The oxygen concentration correction coefficient Ω is compared with the preset correction coefficient Ω0. The sealing status is judged based on the comparison result, and the basic protection scheme is modified once based on the judgment result, wherein: When Ω≤Ω0, the sealing condition is determined to be good, and no modification is made to the basic protection scheme. When Ω > Ω0, the sealing condition is determined to be at risk of leakage. The basic protection scheme is modified to obtain the modified inert gas flow rate f1. f1 is set as f0 × [1 + σ × (Ω - Ω0) / Ωmax], where σ is the flow rate correction coefficient and Ωmax is the maximum oxygen concentration correction coefficient. The modified inert gas flow rate f1 is replaced in the basic protection scheme to obtain the modified protection scheme.

7. The precise feeding device for toxic powder based on inert gas protection according to claim 6, characterized in that, The step of performing secondary compensation on the primary correction process based on the material feeding disturbance feedback parameters to obtain the target protection scheme includes: The feeding disturbance feedback parameters are acquired, including the instantaneous flow rate fluctuation δq and the pressure pulsation at the feeding port δp; The feeding disturbance index Y is calculated based on the instantaneous flow fluctuation δq, the pressure pulsation at the feeding port δp, the first disturbance weight κ1, and the second disturbance weight κ2. Y is set as κ1×|δq| / δqmax+κ2×|δp| / δpmax, where δqmax is the maximum allowable flow fluctuation and δpmax is the maximum allowable pressure pulsation. The feeding disturbance index Y is compared with the preset disturbance index Y0. Based on the comparison result, the disturbance risk status is judged, and based on the judgment result, a second compensation is performed on the first correction process, wherein: When Y≤Y0, the disturbance risk status is determined to be controllable, and no secondary compensation is performed on the first correction process. When Y > Y0, the disturbance risk status is determined to be high-risk. The first correction process is then compensated twice to obtain the target inert gas flow rate f2. f2 is set as f1 × [1 + ρ × (Y - Y0) / Ymax], where ρ is the compensation gain coefficient and Ymax is the maximum feed disturbance index. The target inert gas flow rate f2 is then replaced in the corrected protection scheme to obtain the target protection scheme.

8. The precise feeding device for toxic powder based on inert gas protection according to claim 1, characterized in that, The powder storage mechanism includes a storage tank, an arch-breaking device, and a level sensor; the arch-breaking device is disposed on the inner wall of the storage tank, and the level sensor is disposed on the top of the storage tank and electrically connected to the control mechanism; the storage tank is made of 316L stainless steel, and the inner wall is electropolished with a surface roughness Ra≤0.4μm.

9. The precise feeding device for toxic powder based on inert gas protection according to claim 1, characterized in that, The weighing and metering mechanism includes a weighing sensor, a metering hopper, and a discharge valve; the weighing sensor is an electromagnetic force-compensated weighing sensor with an accuracy class of C3 and a graduation value of no more than 0.1g; the metering hopper adopts a conical design with a cone angle of 60°, and its bottom is connected to the screw conveyor mechanism.

10. The precise feeding device for toxic powder based on inert gas protection according to claim 1, characterized in that, The screw conveyor mechanism includes a variable frequency motor, a screw shaft, and a sealing housing; the screw shaft adopts a variable pitch design, with the pitch at the feed end being 1.5 times that at the discharge end; the connection between the sealing housing and the feeding tower body adopts an air-filled sealing structure, with the air pressure being 0.02 MPa higher than the internal pressure of the tower.

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