Silicon-carbon negative electrode material preparation equipment based on impinging stream fluidized bed

Abstract

The application discloses a silicon-carbon negative electrode material preparation equipment based on a collision type fluidized bed, which comprises a reaction cylinder, a solid material inlet, a gas outlet and a heater are arranged on the reaction cylinder, a distribution bin is sealingly arranged at the lower end of the reaction cylinder, a shaft sleeve seat is sealingly arranged in the distribution bin, a lower stirring paddle is rotationally arranged in the shaft sleeve seat, a gas inlet hole, a flow channel, an upper spray hole and a lower spray hole are arranged in the shaft sleeve seat and are connected with each other, a plurality of upwardly inclined collision nozzles are circumferentially and evenly distributed on the side wall of the distribution bin, an upper stirring paddle is rotationally arranged above the lower stirring paddle, a plurality of downwardly inclined inclined jet flow reinforcement pipes are circumferentially and evenly distributed on the side wall of the reaction cylinder, and the jet directions of the inclined jet flow reinforcement pipes intersect with the stirring shaft. The application can eliminate the dead zone, the main breaking force is the gas flow shear force, the energy consumption of the upper stirring paddle and the lower stirring paddle is reduced, and the fluidized breaking effect is improved.

Description

Technical Field

[0001] This invention relates to the field of battery material preparation equipment technology, and in particular to silicon-carbon anode material preparation equipment based on a collision fluidized bed. Background Technology

[0002] Fluidized bed technology has seen rapid application and development in the preparation of silicon-carbon materials using chemical vapor deposition (CVD) due to its high mass and heat transfer efficiency (gas-solid phase heat transfer coefficient reaches 200-500 W / (m²・K)), high operational flexibility (able to handle particles with wide sieve sizes), and ease of industrial scale-up. Compared with rotary kilns, fluidized beds suspend and disperse carbon substrate particles through airflow fluidization, forming a "dynamic homogeneous contact" with silicon source (such as silane) and carbon source (such as acetylene) gases. The thickness deviation of the silicon-carbon coating layer is controllable, and the energy consumption is low, perfectly meeting the core requirements of large-scale production of silicon-carbon materials.

[0003] However, the structural design of traditional fluidized beds is difficult to meet the diverse needs of silicon-carbon material preparation. Existing equipment mostly adopts the key internal component scheme of "annular gas distributor + agitator", which has relatively fixed flow field characteristics such as airflow distribution and shear intensity. When faced with carbon substrate raw materials with different physical properties, the adaptability is extremely poor: for fine-particle carbon powder or spherical carbon powder, the fixed airflow intensity of the annular inlet is prone to over-fluidization, increasing the particle entrainment rate and decreasing the silane utilization rate; for irregularly shaped or coarse-particle carbon powder, under the same airflow conditions, fluidization is insufficient, some particles are deposited at the bottom of the reactor, the coating thickness deviation is increased, and the structural collapse is caused by uneven local volume expansion during battery cycling.

[0004] With the emergence of diverse new porous carbon particles (such as phenolic resin porous carbon, biomass porous carbon, asphaltene porous carbon, etc.), their microstructures (porosity, sphericity) vary significantly, further amplifying the adaptation shortcomings of traditional equipment.

[0005] Therefore, it is urgent to break through the limitations of traditional silicon-carbon material fluidized beds with "fixed structure and rigid flow field", develop new structures that can flexibly adjust the flow field characteristics, achieve efficient adaptation to various types of carbon substrate raw materials, promote the transformation of silicon-carbon material preparation from "mass production of single specifications" to "flexible manufacturing of multiple varieties", and provide key material support for green and low-carbon industries. Summary of the Invention

[0006] The purpose of this invention is to provide a silicon-carbon anode material preparation device based on a collision fluidized bed, which can eliminate the bottom dead zone, solve the problem of uneven reaction gas concentration, and improve fluidization efficiency by using airflow shear as the main method and stirring shear as the auxiliary method during the fluidization process.

[0007] To achieve the above objectives, the technical solution adopted by this invention is: a silicon-carbon anode material preparation device based on a collision fluidized bed, comprising: a reaction cylinder, on which a solid material inlet, a gas outlet, and a heater are provided; a distribution chamber is sealed at the lower end of the reaction cylinder; a bushing seat is sealed in the distribution chamber; a stirring shaft is rotatably mounted in the bushing seat; a lower stirring paddle on the stirring shaft extends into the reaction cylinder; and a communicating air inlet, flow channel, upper spray hole, and lower spray hole are provided on the bushing seat. The upper spray hole is inclined upwards, and the lower spray hole is inclined downwards. The air inlet is located outside the distribution chamber and is sequentially connected to a preheating tank and a mixing tank. The mixing tank is respectively connected to a carrier gas source, a silicon source process gas source, and a carbon source process gas source. The gas source is connected, and the upper and lower spray holes are evenly distributed on the bushing seat and located in the distribution chamber. Several upward-sloping collision nozzles are evenly distributed on the side wall of the distribution chamber. The spray direction of the collision nozzles converges with the stirring shaft. The collision nozzles are connected to the carrier gas source through the preheating tank. After the stirring shaft extends out of the bushing seat, it is connected to the lower servo reduction motor. An upper stirring paddle is rotatably installed above the lower stirring paddle. The upper stirring paddle is connected to the upper servo reduction motor fixed on the top wall of the reaction cylinder. Several downward-sloping oblique jet enhancement tubes are evenly distributed on the side wall of the reaction cylinder. The spray direction of the oblique jet enhancement tubes converges with the stirring shaft. The oblique jet enhancement tubes pass through the side wall of the reaction cylinder and the heater and are connected to the carrier gas source.

[0008] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, both the upper and lower spray holes are conical holes. The diameter of the inlet end connected to the flow channel is φ1.8mm, and the diameter of the outlet end away from the flow channel is φ1.2mm. The number of upper and lower spray holes is the same, ranging from 20 to 50. The elevation angle of the upper spray hole is 30°, and the depression angle of the lower spray hole is 60°.

[0009] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the number of collision nozzles is 4 to 8, the distance between the outlet end of the collision nozzle and the bottom of the distribution chamber is 2 to 15 cm, the orifice diameter of the collision nozzle is φ2 mm, and the elevation angle of the collision nozzle is 55°.

[0010] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the number of oblique jet enhancement tubes is 6 to 12, the height of the outlet end of the oblique jet enhancement tube is 0.4 times the height of the static bed in the reaction chamber, and the downward angle of the oblique jet enhancement tube is 30°.

[0011] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the lower impeller is a propulsion-type variable diameter structure, with the diameter of the lower impeller decreasing gradually from bottom to top. The upper impeller is also a propulsion-type structure, and the upper and lower impellers have the same azimuth airfoil. The diameter of the upper impeller is a constant diameter structure, and the diameter of the upper impeller is equal to the minimum diameter of the lower impeller.

[0012] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, a cooling tank is provided on the outer wall of the bushing seat, a cooling sleeve is sealed and covered on the cooling tank, and a water-cooling inlet and a water-cooling outlet are provided on the cooling sleeve.

[0013] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the reaction cylinder has at least two gas outlets, each equipped with a metal filter, a backflow valve and a shut-off valve, a safety valve on the reaction cylinder, and a pressure gauge on the safety valve.

[0014] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, backwash valves and flow meters are installed on both the inlet pipeline connected to the collision nozzle and the inlet pipeline connected to the oblique jet enhancement tube. The conventional gas velocity of the carrier gas ejected from the collision nozzle is 20–40 m / s, the backwash pressure of the collision nozzle is 0.25–5 MPa, and the backwash cycle is 5–10 min. The conventional gas velocity of the carrier gas ejected from the oblique jet enhancement tube is 20–35 m / s, the backwash pressure of the oblique jet enhancement tube is 0.25–5 MPa, and the backwash cycle is 20–60 min.

[0015] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the reaction cylinder, distribution chamber, and bushing are all made of special alloy materials that are resistant to high temperatures and corrosion and have good thermal conductivity, in order to adapt to reaction temperatures of 500–900°C and complex chemical gas environments, and to ensure long-term stable operation of the equipment.

[0016] Furthermore, in the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, the heater is a multi-segment electric heating furnace arranged around the reaction cylinder. Each segment of the electric heating furnace has its temperature independently controlled, with a heating range of 200–900°C and a temperature control accuracy of ±2°C. A temperature sensor is installed on the electric heating furnace, and the temperature sensor is connected to an external control system to achieve real-time monitoring and control of the temperature inside the reaction cylinder.

[0017] The advantages of this invention are as follows: Spatial staged air intake is formed through the micro-mixing effect of the upper and lower spray holes, the basic fluidization effect of the impact nozzles, and the macro-convection of the inclined jet enhancement tube, resulting in a more uniform distribution of the reactant gas. The radial concentration deviation of the bed within the reaction chamber is reduced to ±5%, improving the fluidization effect and silicon source utilization. Furthermore, the resulting cross-flow field enhances the airflow shear force, improving the airflow breaking capability. Thus, particle agglomeration is primarily broken up by airflow shear force, with the upper and lower agitators only playing an auxiliary role, thereby reducing the energy consumption of the upper and lower agitators. The upper and lower agitators are independently controlled and can be flexibly set to run in the same direction or... The counter-rotation of the upper and lower impellers creates more complex shear forces and eddies, effectively breaking up particle agglomeration with low energy consumption and enhancing gas-solid contact efficiency. The lower impeller, located near the distribution chamber, is responsible for initial fluidization and particle dispersion. The upper impeller, situated in the upper-middle part of the reaction chamber, suppresses particle settling and promotes secondary mixing. Combined with the cross-flow field, it achieves better stratified fluidization, adapting to the needs of different reaction stages. During fluidization, when deposits adhere to the impeller shaft, the increased airflow velocity in the inclined jet reinforcement tube can peel off the deposits from the impeller shaft, while further eliminating the bottom dead zone. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the silicon-carbon anode material preparation equipment based on a collision fluidized bed as described in this invention.

[0019] Figure 2 yes Figure 1 Schematic diagram of the installation structure of the middle and lower agitator. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0021] like Figure 1 , Figure 2As shown, the silicon-carbon anode material preparation equipment based on a collision fluidized bed according to the present invention includes: a reaction cylinder 1, on which a solid material inlet 11, a gas outlet, and a heater 12 are provided. The reaction cylinder 1 has no less than two gas outlets. A metal filter 13 is provided in the gas outlet. A backflow valve and a shut-off valve are provided on the metal filter 13. The heater 12 is a multi-stage electric heating furnace arranged around the reaction cylinder 1. Each stage of the electric heating furnace has an independently controlled temperature. The heating range is 200-900℃, and the temperature control accuracy is ±2℃. A temperature sensor is provided on the electric heating furnace. The temperature sensor is connected to an external control system to realize real-time monitoring and control of the internal temperature of the reaction cylinder 1. A safety valve 14 is provided on the reaction cylinder 1, and a pressure gauge 141 is provided on the safety valve 14. Porous carbon particles can be added to the reaction chamber 1 through the solid material inlet 11, and the carrier gas and residual process gas can be discharged through the gas outlet. The metal filter 13 can filter out solid particles. When one metal filter 13 becomes blocked, the shut-off valve of another metal filter 13 is opened and the shut-off valve of the blocked metal filter 13 is closed. The backflush valve of the blocked metal filter 13 is opened for backflush. During backflush, the same gas as the carrier gas needs to be used and the gas is preheated. When the pressure gauge 141 on the safety valve 14 detects that the pressure in the reaction chamber 1 is too high, the shut-off valves on all metal filters 13 are opened first to increase the gas output and reduce the pressure in the reaction chamber 1. If the pressure in the reaction chamber 1 is still too high, the safety valve 14 needs to be opened to release the pressure.

[0022] A distribution chamber 2 is sealed at the lower end of the reaction cylinder 1, and a bushing seat 21 is sealed inside the distribution chamber 2. The reaction cylinder 1, distribution chamber 2, and bushing seat 21 are all made of a special alloy material that is resistant to high temperatures and corrosion and has good thermal conductivity to adapt to reaction temperatures of 500-900℃ and complex chemical gas environments, ensuring long-term stable operation of the equipment. A stirring shaft 22 is rotatably mounted inside the bushing seat 21, and a lower stirring blade 3 on the stirring shaft 22 extends into the reaction cylinder 1. The lower stirring blade 3 has a propulsion-type variable diameter structure, with its diameter decreasing gradually from bottom to top. The lower layer of the lower stirring blade 3 with a larger diameter structure can enhance the bottom shear force of the lower stirring blade 3, and the upper layer of the lower stirring blade 3 with a smaller diameter structure can enhance the upward force. The bushing 21 is provided with a connected air inlet 211, a flow channel 212, an upper spray hole 213, and a lower spray hole 214. The upper spray holes 213 and lower spray holes 214 are evenly distributed circumferentially on the bushing 21 and located within the distribution chamber 2. Both the upper spray holes 213 and lower spray holes 214 are tapered holes. The diameter of the inlet end connected to the flow channel 212 is φ1.8mm, and the diameter of the outlet end away from the flow channel 212 is φ1.2mm. The tapered structure enables a more uniform distribution of the fluid velocity sprayed by the upper spray holes 213 and lower spray holes 214, improving the spraying efficiency. The number of upper spray holes 213 and lower spray holes 214 is the same, ranging from 20 to 50. The number of upper spray holes 213 and lower spray holes 214 is adjusted to accommodate different inner diameters. The reaction chamber 1 has an upward-sloping upper nozzle 213 with an elevation angle of 30°, which effectively pushes the gas upward and prevents the fluidized bed in the reaction chamber 1 from collapsing. The lower nozzle 214 is tilted downward with a depression angle of 60°, mainly used to impact the bottom dead zone of the reaction chamber 1. The air inlet 211 is located outside the distribution chamber 2 and is connected in sequence to the preheating tank and the mixing tank. The mixing tank is connected to the carrier gas source, the silicon source process gas source, and the carbon source process gas source, respectively. Several upward-sloping impact nozzles 23 are evenly distributed circumferentially on the side wall of the distribution chamber 2. The impact nozzles 23 have an elevation angle of 55°, and there are 4 to 8 impact nozzles 23. The outlet end of the impact nozzles 23 is connected to the bottom of the distribution chamber 2. The distance between them is 2-15cm. The diameter of the collision nozzle 23 is φ2mm. The jet direction of the upwardly inclined collision nozzle 23 forms an angle with the jet direction of the upper spray hole 213, which promotes particle suspension and tumbling and improves fluidization efficiency. The height of the collision nozzle 23 is 0.2 times the diameter of the reaction cylinder 1, which can balance the jet penetration depth of the collision nozzle 23 and the stability of the bed flow field in the reaction cylinder 1. The jet direction of the collision nozzle 23 intersects with the stirring shaft 22. The collision nozzle 23 is connected to the carrier gas source through the preheating tank. A backwash valve and flow meter are installed on the air inlet pipeline connected to the collision nozzle 23. The normal gas velocity of the carrier gas sprayed by the collision nozzle 23 is 20-40m / s, and the backwash pressure is controlled to be 0.The pressure is 25-5 MPa, and the backflush cycle is 5-10 min. The periodic backflush stabilizes the spray of the impact nozzle 23. The stirring shaft 22 extends out of the bushing seat 21 and is connected to the lower servo reducer motor 4. A cooling tank 215 is provided on the outer wall of the bushing seat 21, and a cooling sleeve 216 is sealed on the cooling tank 215. A water cooling inlet and a water cooling outlet are provided on the cooling sleeve 216. Coolant is introduced into the cooling tank 215 through the cooling inlet and flows out from the cooling outlet. The coolant cools the stirring shaft 22 extending out of the reaction cylinder 1, preventing the heat on the reaction cylinder 1 from being radiated to the lower servo reducer motor 4 and affecting the service life of the lower servo reducer motor 4. An upper stirring paddle 5 is rotatably arranged above the lower stirring paddle 3. The upper stirring paddle 5 is a propeller-type equal diameter structure, and the diameter of the upper stirring paddle 5 is the same as that of the lower stirring paddle 3. The minimum diameters of the upper and lower agitators are equal. The upper agitator 5 and the lower agitator 3 have the same azimuth airfoil. The upper agitator 5 is connected to the upper servo geared motor 51 fixed on the top wall of the reaction cylinder 1. A cooling seat 52 is provided between the upper servo geared motor 51 and the top wall of the reaction cylinder 1 to prevent the upper servo geared motor 51 from being damaged by heat radiation. The upper agitator 5 and the lower agitator 3 are independently controlled and can be flexibly set to rotate in the same or opposite direction. When the two rotate in opposite directions, the shear force and eddy current generated by the interaction between the upper agitator 5 and the lower agitator 3 are more complex, which can effectively break up particle agglomeration and enhance gas-solid contact efficiency. Moreover, the lower agitator 3 is close to the distribution chamber 2 and is responsible for initial fluidization and particle dispersion. The upper agitator 5 is located in the upper middle part of the reaction cylinder 1, which inhibits particle sedimentation and promotes secondary mixing, forming a stratified fluidization effect to meet the needs of different reaction stages. Six to twelve downward-sloping jet enhancement tubes 6 are evenly distributed around the side wall of the reaction cylinder 1. The height of the outlet end of the jet enhancement tube 6 is 0.4 times the height of the static bed in the reaction cylinder 1, and the downward angle of the jet enhancement tube 6 is 30°. The jet directions of the jet enhancement tubes 6 converge at the stirring shaft 22. With this height and downward angle, the impact force of the gas jet in the jet enhancement tube 6 can effectively agitate the material in the distribution chamber 2, and can also break the "sparse center and dense sidewall" structure of the fluidized bed in the reaction cylinder 1. The non-uniform ring-core distribution structure enhances radial mixing and improves the uniform distribution of reactant gas concentration within the reaction cylinder 1. The oblique jet enhancement tube 6 passes through the side wall of the reaction cylinder 1 and the heater 12, and is connected to the carrier gas source. A backwash valve and flow meter are installed on the inlet pipeline connected to the oblique jet enhancement tube 6. The carrier gas velocity ejected from the oblique jet enhancement tube 6 is 20–35 m / s, the backwash pressure is 0.25–5 MPa, and the backwash cycle is 20–60 min. Periodic backwashing stabilizes the ejection of the oblique jet enhancement tube 6.

[0023] The method for preparing silicon-carbon anode materials, using the aforementioned silicon-carbon anode material preparation equipment based on a collision fluidized bed, comprises the following steps:

[0024] S1. Feeding: Porous carbon particles are fed into the reaction cylinder 1 through the solid material inlet 11, and the solid material inlet 11 is closed.

[0025] S2. Fluidization and Dispersion: The carrier gas source is turned on. After preheating in the preheating tank, the carrier gas sequentially enters the inlet 211, flow channel 212, upper spray hole 213, lower spray hole 214, collision nozzle 23, and oblique jet enhancement pipe 6, and is sprayed into the reaction cylinder 1. The jets generated by the upper spray hole 213, lower spray hole 214, collision nozzle 23, and oblique jet enhancement pipe 6 collide to form a mixed flow field, fluidizing the porous carbon particles. The upper spray hole 213 sprays the carrier gas upwards to enhance the diffusion of the upper part of the bed, maintaining the bed expansion inside the reaction cylinder 1. The lower spray hole 214... The carrier gas is sprayed downwards to impact the dead zone at the bottom of the reaction cylinder 1, and at the same time, the air in the reaction cylinder 1 is replaced. Then, the lower stirring paddle 3 is rotated to disperse the porous carbon particles in the reaction cylinder 1. Then, the upper stirring paddle 5 is rotated in the opposite direction. The lower stirring paddle 3 and the upper stirring paddle 5 rotate in the opposite direction to inhibit particle agglomeration and bubble merging and enhance fluidization efficiency. Then, the heater 12 is started to heat the reaction cylinder 1 to a temperature of 700-900℃. The temperature is maintained for 2-4 hours. The porous carbon particles are annealed under the protection of the carrier gas to form a porous carbon skeleton.

[0026] During the transition of porous carbon particles from an initial static state to a stable fluidized state, the carrier gas velocity in the impact nozzle 23 is 35 m / s, which quickly penetrates the porous carbon particle layer. The strong shear force rapidly disperses the porous carbon particles, achieving rapid fluidization. When the upper impeller 5 and the lower impeller 3 rotate in opposite directions, the rotation speed of the lower impeller 3 is 10% to 30% higher than that of the upper impeller 5, and this continues for 1 to 2 hours. A cross flow field is formed between the upper impeller 5 and the lower impeller 3 rotating in opposite directions. The shear force generated by the cross flow field breaks up particle agglomeration and reduces dead zones. Setting a speed difference can increase the shear force of the cross flow field, resulting in better fluidization. After rotating in opposite directions for 1 to 2 hours, the porous carbon particles are basically in a good fluidized state. Then, the upper impeller 5 switches from counter-rotation to forward rotation, and the rotation speed of the upper impeller 5 and the lower impeller 3 is the same. At this time, rotating the upper impeller 5 and the lower impeller 3 in the same direction and at the same speed can form a relatively stable flow field, avoiding excessive crushing of the porous carbon particles.

[0027] S3, Silicon deposition: When the temperature inside the reaction chamber drops to 450-550℃, the silicon source process gas source is turned on, allowing the silicon source process gas and carrier gas to mix in the mixing tank to form a mixed gas. The volumetric flow ratio between the silicon source process gas and the carrier gas in the mixing tank is 1:2-10. After preheating in the preheating tank, the mixed gas enters the upper spray hole 213 and lower spray hole 214 through the inlet 211 and flow channel 212, and is then sprayed into the reaction chamber 1. Under the stirring action of the upper impeller 5 and lower impeller 3, the silicon source process gas is evenly dispersed. The silicon source process gas decomposes at high temperature to form nano-silicon particles. The nano-silicon particles are chemically vapor-deposited with the porous carbon framework to form silicon-carbon particles. During this process, the upper spray hole 213 sprays the mixed gas upward, thus supplying the silicon source process gas. Furthermore, it enhances the upper diffusion of the bed and maintains the expansion of the bed inside the reaction cylinder 1. The mixed gas sprayed downward from the lower nozzle 214 not only delivers silicon source process gas but also impacts the dead zone at the bottom of the reaction cylinder 1. The carrier gas sprayed from the collision nozzle 23 is counter-collision with the mixed gas sprayed from the upper nozzle 213 and the lower nozzle 214. The carrier gas velocity in the collision nozzle 23 is 20-40 m / s. At the same time, the carrier gas sprayed from the inclined jet enhancement tube 6 is counter-collision for a second time. The carrier gas velocity in the inclined jet enhancement tube 6 is 20-35 m / s, which compresses the radial concentration deviation of the bed in the reaction cylinder 1 to ±5%. The carrier gas sprayed from the inclined jet enhancement tube 6 is automatically heated after passing through the thermal radiation of the heater 12, so there is no need to set up an additional preheating tank for preheating.

[0028] S4. Carbon Coating: When the temperature inside the reaction chamber 1 reaches 500-650℃, the carbon source process gas source is turned on, allowing the carbon source process gas and carrier gas to mix in the mixing tank to form a mixed gas. The volumetric flow ratio between the carbon source process gas and the carrier gas in the mixing tank is 1:4-20. After preheating in the preheating tank, the gas enters the upper spray hole 213 and lower spray hole 214 through the inlet 211 and flow channel 212, and is then sprayed into the reaction chamber 1. The carbon source process gas is evenly dispersed and decomposes at high temperature to form carbon black. The carbon black coats the surface of the silicon-carbon particles, ultimately forming a silicon-carbon anode material. During this process, the upper spray hole 213 is directed upwards. The injected mixed gas not only delivers the carbon source process gas but also enhances the diffusion in the upper part of the bed, maintaining the bed expansion in the reaction cylinder 1. The lower nozzle 214 injects the mixed gas downwards, delivering the carbon source process gas and impacting the dead zone at the bottom of the reaction cylinder 1. The carrier gas injected from the collision nozzle 23 is counteracted by the mixed gas injected from the upper nozzle 213 and the lower nozzle 214. The carrier gas velocity in the collision nozzle 23 is 20-40 m / s. At the same time, the carrier gas injected from the oblique jet enhancement tube 6 is counteracted a second time. The carrier gas velocity in the oblique jet enhancement tube 6 is 20-35 m / s, compressing the radial concentration deviation of the bed in the reaction cylinder 1 to ±5%.

[0029] In S2, S3 and S4, the jets from the upper nozzle 213, the lower nozzle 214, the impact nozzle 23 and the oblique jet reinforcement tube 6 cross-collision creates a strong airflow shear force, which improves the airflow breaking ability. In this way, the airflow shear force is mainly used to break up particle agglomerates, and the upper agitator 5 and the lower agitator 3 only play an auxiliary breaking role, thereby reducing the energy consumption of the upper agitator 5 and the lower agitator 3.

[0030] In S3 and S4, the gas velocity of the mixed gas needs to be instantaneously increased to 50 m / s every 2 hours and then maintained for 5 minutes to prevent blockage in the upper nozzle 213 and lower nozzle 214. At the same time, the rotation speed of the lower impeller 3 is increased by 30% within 3 to 5 seconds. While the rotation speed of the lower impeller 3 is increased, the rotation speed of the upper impeller 5 remains unchanged. The original flow field balance is disrupted by instantaneously increasing the gas velocity and the rotation speed of the lower impeller 3, thereby improving fluidization efficiency. After the mixed gas returns to the normal gas velocity, the carrier gas velocity in the inclined jet enhancement tube 6 is instantaneously increased to 50 m / s and then maintained for 5 minutes. The rotation speed of the lower impeller 3 remains unchanged. When the carrier gas in the inclined jet enhancement tube 6 returns to the normal gas velocity, the rotation speed of the lower impeller 3 slowly decreases to the normal rotation speed. The instantaneous increase in the gas velocity in the inclined jet enhancement tube 6 can flush the deposits on the stirring shaft 22, while the high rotation speed of the stirring shaft 22 can accelerate the stripping of deposits.

[0031] In this embodiment, the carrier gas is either nitrogen or argon; the silicon source process gas is any one or more of silane, silane, hexamethyldisilane, chlorosilane, and tetrafluorosilane; and the carbon source process gas is any one or more of methane, ethane, ethylene, acetylene, and propylene.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A silicon-carbon negative electrode material preparation apparatus based on an opposed fluidized bed, comprising: The utility model provides a reaction cylinder, is provided with solid material import, gas export and heater on the reaction cylinder, its characterized in being: the distribution bin is sealed to be provided with in the lower end of reaction cylinder, is sealed to be provided with the shaft sleeve seat in distribution bin, is rotatoryly provided with the stirring shaft in the shaft sleeve seat, and the lower stirring paddle on stirring shaft extends into the reaction cylinder, and the lower stirring paddle is the propelling type variable diameter structure, and the diameter of lower stirring paddle presents gradiently decreasing from lower to upper, is provided with the gas inlet hole, flow channel, upper spray hole and lower spray hole that are connected in the shaft sleeve seat, and the upper spray hole is obliquely upwards, and the lower spray hole is obliquely downwards, and the upper spray hole and lower spray hole are all conical holes, and the hole diameter of the inlet end connected with flow channel is phi 1.8mm, and the hole diameter of the outlet end away from flow channel is all phi 1.2mm, and the number of upper spray hole and lower spray hole is same, and is 20-50, and the elevation angle of upper spray hole is 30 DEG, and the depression angle of lower spray hole is 60 DEG, and the gas inlet hole is located in the outside of distribution bin and is connected with preheating tank and mixing tank in turn, and mixing tank is connected with carrier gas source, silicon source process gas source and carbon source process gas source respectively, and the upper spray hole and lower spray hole are distributed on the shaft sleeve seat and are located in distribution bin, and the side wall of distribution bin is circumferentially distributed with several upwardly inclined counter jet nozzles, and the jet direction of counter jet nozzle converges on stirring shaft, and counter jet nozzle is connected with carrier gas source through preheating tank, and stirring shaft is connected with lower servo speed reducer after extending out of shaft sleeve seat, and is rotatoryly provided with upper stirring paddle above lower stirring paddle, and upper stirring paddle is also propelling type structure, and upper stirring paddle and lower stirring paddle are the same direction wing type, and the diameter of upper stirring paddle is equal diameter structure, and the diameter of upper stirring paddle is equal to the minimum diameter of lower stirring paddle, and upper stirring paddle is connected with upper servo speed reducer fixed on the top wall of reaction cylinder, and the side wall of reaction cylinder is circumferentially distributed with several downwardly inclined inclined jet flow reinforcement tubes, and the jet direction of inclined jet flow reinforcement tube converges on stirring shaft, and inclined jet flow reinforcement tube is connected with carrier gas source after passing through the side wall of reaction cylinder and heater.

2. The silicon-carbon negative electrode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: The number of counter jet nozzles is 4-8, the distance between the outlet end of counter jet nozzle and the bottom of distribution bin is 2-15cm, the hole diameter of counter jet nozzle is phi 2mm, and the elevation angle of counter jet nozzle is 55 DEG.

3. The silicon-carbon negative electrode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: The number of inclined jet flow reinforcement tubes is 6-12, the height of outlet end of inclined jet flow reinforcement tube is 0.4 times of the static bed height of reaction cylinder, and the depression angle of inclined jet flow reinforcement tube is 30 DEG.

4. The silicon-carbon negative electrode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: Cooling groove is arranged on the outside wall of shaft sleeve seat, cooling jacket is sealed to cover on cooling groove, and water cooling inlet and water cooling outlet are arranged on cooling jacket.

5. The silicon-carbon negative electrode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: The number of gas outlets on reaction cylinder is not less than two, metal filter is arranged in gas outlet, backflush valve and stop valve are arranged on metal filter, safety valve is arranged on reaction cylinder, and pressure gauge is arranged on safety valve.

6. The silicon-carbon anode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: The backflush valve and flow meter are arranged on the gas inlet pipeline connected with the impinging jet nozzle and the gas inlet pipeline connected with the inclined jet reinforced tube, the conventional gas velocity of the carrier gas sprayed by the impinging jet nozzle is 20-40 m / s, the backflush pressure of the impinging jet nozzle is 0.25-5 MPa, and the backflush period is 5-10 min; the conventional gas velocity of the carrier gas sprayed by the inclined jet reinforced tube is 20-35 m / s, the backflush pressure of the inclined jet reinforced tube is 0.25-5 MPa, and the backflush period is 20-60 min.

7. The silicon-carbon anode material preparation apparatus based on a pair-impingement fluidized bed according to claim 1, characterized in that: The heater is a multi-section electric heating furnace arranged around the reaction cylinder, each section of the electric heating furnace is independently controlled in temperature, the heating range is 200-900 DEG C, the temperature control precision is ± 2 DEG C, and a temperature sensor is arranged on the electric heating furnace, the temperature sensor is connected with an external control system and used for real-time monitoring and regulation of the temperature inside the reaction cylinder.

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