A continuous spray fluidized bed coating device for silicon-carbon negative electrode particles

Abstract

The utility model discloses a kind of for silicon-carbon negative electrode particle's continuous spray fluidized bed coating device, including vertically integrated reaction tower, reaction tower from bottom to top sequentially include fluidized section, spray section and ageing section, fluidized section is used to convert silicon-carbon particle into fluidized state, spray section inner wall is provided with ultrasonic atomizing nozzle assembly of spiral array arrangement to form uniform mist field;Perforated baffle is provided between ageing section and the spray section, annular air curtain device is provided in ageing section interior to realize gas flow and speed adjustment;Feed system is used to provide silicon-carbon negative electrode particle and precursor solution, the utility model solves the uneven coating of existing fluidized bed coating equipment, particle is easy to break, the problem of non-continuous process, by three-section collaborative design, ultrasonic auxiliary atomization and residence time accurate control, realize to silicon-carbon negative electrode material high efficiency, uniformly, continuous nanoscale metal oxide coating, breakage rate is low, and coating layer compactness is good.

Description

Technical Field

[0001] This utility model relates to the technical field of fluidized bed coating equipment, specifically to a continuous spray fluidized bed coating device for silicon-carbon anode particles. Background Technology

[0002] In the manufacturing of silicon-carbon anode materials for lithium-ion batteries, coating the surface with a uniform layer of nano-metal oxides (such as titanium dioxide, alumina, etc.) is a key process for improving its initial efficiency, cycle stability, and rate performance. Currently, the commonly used batch stirred tank reactor has significant drawbacks: First, the process cycle is long, lasting several hours, with poor batch-to-batch consistency, and single-reactor capacity is typically less than 500 kg / day, making it difficult to meet the demands of large-scale mass production; second, the shear force generated by mechanical stirring easily leads to the breakage of brittle silicon-carbon particles (breakage rate > 15%), exacerbating the volume expansion effect during battery cycling; finally, the significant concentration and temperature gradients within the reactor result in uneven coating thickness (deviation > 20%), severely impacting battery life.

[0003] In recent years, some fluidized bed technologies have been attempted for continuous coating, but problems such as uneven fluidization and severe particle agglomeration still exist. The coating qualification rate for micron-sized silicon-carbon particles (D50=5-20μm) is usually below 85%. Although spray drying technology can achieve continuous production, rapid drying easily causes microcracks in the coating layer, resulting in limited improvement in initial efficiency (<3%). More importantly, existing technologies lack precise means to control the hydrolysis-deposition kinetics of metal oxide precursors, making it impossible to effectively control the density of the coating layer and its interfacial bonding with the substrate.

[0004] Therefore, developing specialized equipment that can achieve efficient and continuous production, minimize particle damage, ensure a highly uniform and dense coating layer, and precisely control the reaction process has become an urgent need to overcome the industrialization bottleneck of silicon-carbon anode materials. Utility Model Content

[0005] This invention aims to solve the problems of uneven coating, easily broken particles, and discontinuous process in existing fluidized bed coating equipment. The objective is to provide a continuous spray fluidized bed coating device for silicon-carbon anode particles.

[0006] This utility model is achieved through the following technical solution: A continuous spray fluidized bed coating device for silicon-carbon anode particles, comprising: The coating reaction system is a vertically integrated reaction tower. The reaction tower includes a fluidization section, a spray section and an aging section from bottom to top. A fluidized carrier gas inlet is opened at the bottom of the fluidization section. The fluidized carrier gas inlet is connected to the gas source section. A gas distribution plate is provided above the fluidized carrier gas inlet. The inner wall of the spray section is circumferentially arranged with an ultrasonic atomizing nozzle assembly in a spiral array to form a uniform mist field. A porous baffle is provided between the aging section and the spray section. The opening ratio of the porous baffle is adjustable and is driven by a pneumatic actuator. An annular air curtain device is provided inside the aging section to realize the adjustment of air flow and speed. An air outlet is provided at the top of the aging section. A feeding system for providing silicon-carbon anode particles and a precursor solution, wherein the silicon-carbon anode particles enter the fluidization section and the precursor solution enters the ultrasonic atomizing nozzle assembly.

[0007] As one of the preferred technical solutions, the ultrasonic atomizing nozzle assembly includes several atomizing nozzles and several ultrasonic transducers. The angle between the axial direction of each atomizing nozzle and the tangent of the tower wall is 25-35°. Each ultrasonic transducer is connected to the corresponding atomizing nozzle, and the distance between the ultrasonic transducer and the outlet of the atomizing nozzle is 10-20 mm.

[0008] As one of the preferred technical solutions, the gas distribution plate is connected to an ultrasonic generator.

[0009] As one of the preferred technical solutions, the reaction tower wall is provided with a condensate micro-circulation channel to maintain a constant humidity inside the reaction tower; The width of the condensate microcirculation channel is 2-3 mm; the condensate inlet of the condensate microcirculation channel is located in the fluidization section, and its condensate outlet is located in the aging section. The reaction tower wall is connected to an ammonia micro-injection unit, which is used to adjust the pH value of the spray section.

[0010] As one of the preferred technical solutions, the spray section is also equipped with a humidity sensor and a pH detector. Both the humidity sensor and the pH detector are electrically connected to a DCS system. The DCS system controls the ammonia micro-injection unit to adjust the amount of ammonia entering.

[0011] As one of the preferred technical solutions, a hot air furnace is provided between the gas source section and the fluidized carrier gas inlet, and a filter screen is provided at the gas outlet.

[0012] As one of the preferred technical solutions, a product processing system is also included, which comprises a cyclone separator, a fluidized dryer, a vibrating screen and a receiving hopper connected in sequence; the cyclone separator is connected to the fluidized section.

[0013] As one of the preferred technical solutions, it also includes an exhaust gas processor, which is connected to the exhaust port of the cyclone separator and the top exhaust port of the aging section through gas transmission pipes.

[0014] As one of the preferred technical solutions, the porous baffle is mirror polished or coated with Teflon, and the atomizing nozzle is made of corrosion-resistant titanium alloy.

[0015] On the other hand, this utility model also provides an application of the above-mentioned continuous spray fluidized bed coating device for silicon-carbon anode particles in coating the surface of silicon-carbon anode materials with metal oxides such as titanium dioxide, zirconium oxide or aluminum oxide.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: 1. Through three-segment collaborative design, ultrasonic-assisted atomization, and precise control of the residence time of porous baffles, efficient, uniform, and continuous nanoscale metal oxide coating of silicon-carbon anode materials is achieved, with low breakage rate and good coating density.

[0017] 2. Low particle damage: No mechanical stirring is required throughout the process. Relying on airflow fluidization, the breakage rate of silicon carbide particles is greatly reduced (<5%).

[0018] 3. Uniform and dense coating: Ultrasonic atomization produces micron-sized uniform droplets, and the uniform mist field formed by the spiral nozzles ensures that the coating thickness deviation is less than 10% and there are no microcracks. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the structure of the gas distribution plate of this utility model; Figure 3 This is a schematic diagram of the structure of the ultrasonic atomizing nozzle assembly of this utility model; Figure 4 This diagram illustrates the connection relationships of the various components in the ultrasonic atomizing nozzle assembly of this utility model. Figure 1 ; Figure 5 This diagram illustrates the connection relationships of the various components in the ultrasonic atomizing nozzle assembly of this utility model. Figure 2 .

[0020] The attached diagram shows the markings and corresponding component names: 1-Gas source section; 2-Hot air furnace; 3-Feed hopper; 4-Storage tank; 5-Precision metering pump; 6-Gas distribution plate; 7-Fluidization section; 8-Spray section; 9-Aging section; 10-Ultrasonic atomizing nozzle assembly; 101-Atomizing nozzle; 102-Ultrasonic transducer; 103-Liquid channel; 104-Generator connection port; 11-Filter screen; 12-Cyclone separator; 13-Fluidized dryer; 14-Vibrating screen; 15-Receiving hopper; 16-Tail gas processor; 17-Condensate inlet; 18-Condensate outlet; 19-PH detector; 20-Humidity sensor; 21-Ammonia inlet; 22-DCS system; 23-Porous baffle; 24-Annular air curtain device. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0022] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In the description of this utility model, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model. Example 1

[0024] This embodiment 1 provides a continuous spray fluidized bed coating device for silicon-carbon anode particles, which can be applied to coating the surface of silicon-carbon anode materials with metal oxides such as titanium dioxide, zirconium oxide, or aluminum oxide.

[0025] like Figure 1 As shown, it specifically includes a feeding system for providing silicon-carbon anode particles and precursor solutions required for the reaction; it also includes a coating reaction system, which is a vertically integrated reaction tower, and the reaction tower includes a fluidization section 7, a spray section 8 and an aging section 9 from bottom to top.

[0026] The fluidization section 7 has a fluidizing carrier gas inlet at its bottom, which is connected to the gas source section 1. The fluidizing carrier gas provided by the gas source section 1 is an inert gas, including but not limited to one or a mixture of nitrogen, argon, and helium, more preferably nitrogen, thereby converting the silicon-carbon anode particles into a fluidized state. Furthermore, a hot air furnace 2 is provided between the gas source section 1 and the fluidizing carrier gas inlet for preheating the fluidizing carrier gas.

[0027] Additionally, a feed hopper 3 is provided at one end of the fluidization section 7, and a screw feeder is installed inside the feed hopper 3. The silicon-carbon anode particles enter from the feed hopper 3 and pass through the screw feeder into the fluidization section 7. During this process, the feed hopper 3 is sealed and connected to the gas source 1, thereby ensuring that the silicon-carbon anode particles can enter the fluidization section 7 at a certain rate under nitrogen protection.

[0028] A gas distribution plate 6 is provided above the fluidizing carrier gas inlet. The gas distribution plate 6 can make the fluidizing carrier gas enter the material layer evenly, fully fluidize the raw material, and prevent the accumulation of silicon-carbon anode particles.

[0029] What we can know is that, combined Figure 1 and Figure 2 As shown, the gas distribution plate 6 in this embodiment is configured as a double layer. The double-layer gas distribution plate 6 is connected to an ultrasonic generator. Specifically, the ultrasonic generator is configured with multiple ultrasonic transducers. The ultrasonic transducers are small in size and are uniformly installed at the bottom of the gas distribution plate 6 by welding without affecting the normal operation of the gas distribution plate 6.

[0030] The ultrasonic generator transmits ultrasonic vibrations to the entire distribution plate at a frequency of 20-40 kHz. The resulting effect is that the high-frequency ultrasonic vibrations continuously dislodge particles that may clog the micropores, achieving self-cleaning of the gas distribution plate 6, ensuring consistently uniform airflow, and guaranteeing uniform coating from the source.

[0031] Above the fluidization section 7 is the spray section 8. Specifically, the inner wall of the spray section 8 is circumferentially arranged with a spiral array of ultrasonic atomizing nozzle assemblies 10 to provide a uniform mist field. In this embodiment, the precursor solution enters the ultrasonic atomizing nozzle assembly 10 for atomization. The specific process is as follows: the precursor solution is stored in a storage tank 4, and the storage tank 4 enters the ultrasonic atomizing nozzle assembly 10 through a corrosion-resistant conduit. In addition, a precision metering pump 5 is installed on the corrosion-resistant conduit to ensure that the flow rate of the precursor solution entering the ultrasonic atomizing nozzle assembly 10 is controllable. Finally, the ultrasonic atomizing nozzle assembly 10 uniformly atomizes the precursor solution into the spray section 8.

[0032] Furthermore, combined Figure 1 and Figure 3 As shown, the ultrasonic atomizing nozzle assembly 10 includes several atomizing nozzles 101 and several ultrasonic transducers 102. Each atomizing nozzle 101 is inclined inwards rather than vertically, that is, the angle between the axis of the atomizing nozzle 101 and the tangent of the tower wall is 25-35°. Each ultrasonic transducer 102 is connected to the corresponding atomizing nozzle 101 and the distance between the ultrasonic transducer 102 and the outlet of the atomizing nozzle 101 is 10-20 mm.

[0033] Specific connection methods are as follows: Figure 4 or Figure 5 As shown, a liquid channel 103 is provided inside the atomizing nozzle 101. The ultrasonic transducer 102 can be disposed on the liquid channel 103 or installed on one side of the atomizing nozzle 101. A generator connection port 104, which mates with the ultrasonic transducer 102, is also connected to one side of the atomizing nozzle 101. Figure 4 (Not shown).

[0034] Specifically, the ultrasonic transducer 102 provides high-frequency vibration energy for atomization, and the atomizing nozzle 101 controls the droplet movement direction, atomization range, and uniformity through structural constraints. The combination of the two can stably generate micron-sized droplet clusters of 1-100μm. This design enables the droplets to be uniformly dispersed, forming a swirling flow field. Combined with the ultrasonic transducer on the tower wall to prevent agglomeration and adhesion, it greatly improves contact efficiency and coating uniformity.

[0035] The atomizing nozzle 101 is made of corrosion-resistant titanium alloy. Titanium alloy is a metal material formed by adding alloying elements such as aluminum, vanadium, molybdenum, and palladium to pure titanium, ultimately achieving a comprehensive value of high strength, light weight, strong corrosion resistance, and long service life.

[0036] Furthermore, the silicon-carbon anode particles enter the spray section 8 under the action of the carrier gas, while the precursor solution forms a group of micron-sized droplets under the action of the ultrasonic atomizing nozzle assembly 10. The silicon-carbon anode particles and the atomized precursor solution come into efficient contact, and the precursor solution undergoes a directional hydrolysis reaction under a controllable humidity environment.

[0037] Above the spray section 8 is the aging section 9. Between the aging section 9 and the spray section 8, there is a perforated baffle 23. The specific opening ratio of the perforated baffle 23 is adjustable and driven by a pneumatic actuator.

[0038] Specifically, the perforated baffle 23 consists of two circular plates of the same size, stacked one on top of the other. Both circular plates have holes arranged in a certain pattern. The lower circular plate is fixed (fixed plate), while the upper circular plate (movable plate) rotates around a central axis via a pneumatic actuator.

[0039] The opening ratio is at its maximum (equal to the opening ratio of a single plate) when the movable plate rotates to completely overlap with the hole in the fixed plate. The opening ratio is at its minimum when the movable plate rotates to completely offset the hole in the fixed plate. By rotating the movable plate, the opening ratio can be continuously adjusted from 0 to the maximum opening ratio.

[0040] Specifically, the pneumatic actuator is a stepper motor or pneumatic actuator installed outside the reaction tower, which drives the movable plate to rotate through a linkage or gear mechanism. Finally, the porosity of the porous baffle 23 can be steplessly adjusted, thereby precisely controlling the residence time of particles in this section and ensuring that the coating layer completes sufficient crystal transformation and interfacial bonding.

[0041] Furthermore, the particles that have completed the initial coating in the lower spray section 8 are carried by the rising airflow and rush towards the porous baffle 23. The airflow and particles can only pass through the currently open holes. By controlling the porosity, much like controlling a "valve," the flow rate of the rising material is limited and evenly distributed. A larger porosity results in a faster flow rate and a shorter residence time; a smaller porosity results in the opposite. After passing through the holes, the particles enter the wide and stable aging section 9. Due to the sudden decrease in flow velocity, the particles begin to settle slowly. At the same time, in this stable environment, the coating layer undergoes final dehydration condensation and crystallization, forming a strong and dense protective layer.

[0042] Furthermore, the inner walls of all the holes in the porous baffle 23 and the upper surface of the plate are mirror polished or coated with PTFE (Teflon) to effectively prevent particle adhesion.

[0043] An annular air curtain device 24 is installed inside the aging section 9. The annular air curtain device 24 includes air curtain nozzles. In this embodiment, the air curtain nozzles spray inert airflows at different speeds toward the center of the tower, forming an air curtain with a velocity gradient to achieve aerodynamic pre-classification of particles. Preferably, at least two layers of annular air curtain nozzles are provided in the vertical aging space, and the airflow rate and airflow velocity can be independently adjusted to achieve differentiated residence time control for particles of different sizes.

[0044] Specifically, finer particles with insufficient coating are lifted by the upper low-speed air curtain due to their light weight, thus prolonging their aging time; while coarser particles with complete coating penetrate the air curtain and enter the next stage, and are eventually discharged preferentially from the bottom, achieving differentiated residence time control for particles of different sizes. Example 2

[0045] After aging, the material enters the product processing system from the top of the tower. Specifically, the product processing system includes a cyclone separator 12, a fluidized bed dryer 13, a vibrating screen 14, and a receiving hopper 15 connected in sequence. The process is as follows: the material first enters the cyclone separator 12 from the top of the tower for efficient gas-solid separation. The coated particles then enter the fluidized bed dryer 13 (80°C) under nitrogen protection to remove residual solvents. After passing through the vibrating screen 14, the finished product is obtained and finally collected in the receiving hopper 15. During this process, the fluidized bed dryer 13 is also connected to the gas source unit 1, which provides nitrogen to the fluidized bed dryer 13. Example 3

[0046] The top of the aging section 9 has an air outlet, and a filter screen 11 is installed at the air outlet. The filter screen 11 only allows exhaust gas to pass through, preventing silicon-carbon negative electrode particles from flowing out.

[0047] Additionally, the exhaust port is connected to the exhaust gas processor 16 via an exhaust pipe, and the exhaust gas processor 16 is also connected to the exhaust port of the cyclone separator 12 via an exhaust pipe. In other words, the exhaust gas processor 16 is used to treat harmful gases generated during the production process, preventing environmental pollution.

[0048] In conjunction with Examples 1-3, the spray fluidized bed coating device of this utility model can achieve continuous production. The vertically integrated design realizes the continuous process from feeding, reaction, aging to drying, and the production capacity is significantly higher than that of batch reactors. Example 4

[0049] To ensure a controllable reaction environment in the atomization section, a condensate micro-circulation channel is provided on the tower wall to maintain constant humidity inside the tower; the specific width of the condensate micro-circulation channel is 2-3 mm; the condensate inlet 17 of the condensate micro-circulation channel is located in the fluidization section 7, and its condensate outlet 18 is located in the aging section 9. The reaction tower wall is also provided with an ammonia inlet 21 located in the spray section 8. The ammonia inlet 21 is connected to an ammonia micro-injection unit, which is used to adjust the pH value of the spray section 8.

[0050] Furthermore, the spray section 8 is equipped with a humidity sensor 20 and a pH detector 19 to detect real-time humidity and pH changes in the spray section 8. Through the synergistic effect of humidity and pH, the condensate microcirculation system maintains a constant humidity field, and a trace amount of ammonia (50ppm) is injected simultaneously to regulate the local pH, thereby stabilizing the hydrolysis rate of the precursor solution. Both the humidity sensor 20 and the pH detector 19 are electrically connected to a DCS system 22, which controls the ammonia micro-injection unit to adjust the amount of ammonia entering the system.

[0051] Specifically, the DCS system 22 can control the ammonia micro-injection unit to adjust the pH value based on the feedback from the pH detector 19.

[0052] In addition, the DCS system 22 is a distributed control system. In this embodiment, an electro-proportional valve is also installed on the liquid channel inside the atomizing nozzle 101. The electro-proportional valve is also electrically connected to the DCS system 22. Specifically, during the operation of the DCS system 22, the pH detector and humidity sensor detect changes in pH and humidity in real time and transmit the signals to the DCS system. The DCS system compares the measured values ​​with the set values ​​and outputs control signals to the electro-proportional valve through calculation to adjust the atomizing air pressure.

[0053] The DCS system 22 can also automatically link and adjust the atomizing air pressure, the precision metering pump 5, and the pneumatic actuator (to adjust the opening rate of the porous baffle 23). Thus, by integrating and controlling key parameters such as humidity, pH, and residence time through the DCS system 22, it can accurately regulate the hydrolysis and deposition process of the precursor, with good reproducibility and high product consistency.

[0054] The DCS system 22 can form a closed-loop control system to ensure that the hydrolysis deposition process is stable within the optimal process window.

[0055] The specific working process of one embodiment of this utility model is as follows: Silicon-carbon anode particles are fed into a nitrogen-protected, sealed feed hopper 3 (oxygen content <100 ppm) at a rate quantitatively via a variable frequency screw feeder to the fluidization section 7. Nitrogen, preheated to 65±20℃ by a hot air furnace 2, rises uniformly through a double-layer gas distribution plate 6 (35% porosity) to form a stable fluidized bed, thus placing the 5-20μm silicon-carbon particles in a turbulent suspension state. Simultaneously, the precursor solution (8wt% concentration, pH=2.8) in the storage tank is pumped to the spray section 8 at a flow rate of 20 L / min via a precision metering pump 5. The ultrasonic atomizing nozzle assembly 10, arranged spirally, forms micron-sized droplet clusters of the precursor solution under the action of the atomizing nozzle 101 (atomization pressure 0.4 MPa), which are further refined by the action of a 40kHz ultrasonic transducer 102.

[0056] Subsequently, the atomized sol and fluidized particles come into efficient contact in a swirling flow field, and the titanium precursor solution undergoes a directional hydrolysis reaction under a controlled humidity environment (60±5% RH). A real-time humidity sensor 20 adjusts the atomizing gas pressure to ensure a stable hydrolysis rate (deposition rate ≈ 12 nm / min). The coated particles rise with the airflow to the aging section 9, where they remain for approximately 15 minutes under the control of an adjustable porous baffle 23 and an annular air curtain nozzle (50% porosity), completing oxide crystal transformation and interfacial bonding enhancement. Finally, the material enters the cyclone separator 12 at the top of the tower for efficient gas-solid separation. The resulting coated particles are then subjected to a nitrogen-protected fluidized dryer 13 to remove residual solvent, and finally, the finished product is obtained by vibrating sieving.

[0057] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A continuous spray fluidized bed coating device for silicon-carbon anode particles, characterized in that, include: The coating reaction system is a vertically integrated reaction tower. The reaction tower includes a fluidization section, a spray section and an aging section from bottom to top. A fluidized carrier gas inlet is opened at the bottom of the fluidization section. The fluidized carrier gas inlet is connected to the gas source section. A gas distribution plate is provided above the fluidized carrier gas inlet. The inner wall of the spray section is circumferentially arranged with an ultrasonic atomizing nozzle assembly in a spiral array to form a uniform mist field. A perforated baffle is provided between the aging section and the spray section. The perforation rate of the perforated baffle is adjustable and driven by a pneumatic actuator. An annular air curtain device is provided inside the aging section to realize the adjustment of air flow and speed. An air outlet is provided at the top of the aging section. A feeding system for providing silicon-carbon anode particles and a precursor solution, wherein the silicon-carbon anode particles enter the fluidization section and the precursor solution enters the ultrasonic atomizing nozzle assembly.

2. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 1, characterized in that, The ultrasonic atomizing nozzle assembly includes several atomizing nozzles and several ultrasonic transducers. The angle between the axial direction of each atomizing nozzle and the tangent of the tower wall is 25-35°. Each ultrasonic transducer is connected to the corresponding atomizing nozzle, and the distance between the ultrasonic transducer and the outlet of the atomizing nozzle is 10-20 mm.

3. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 1, characterized in that, The gas distribution plate is connected to an ultrasonic generator.

4. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 1, characterized in that, The reaction tower wall is provided with a condensate micro-circulation channel to maintain a constant humidity inside the reaction tower; The width of the condensate microcirculation channel is 2-3 mm; the condensate inlet of the condensate microcirculation channel is located in the fluidization section, and its condensate outlet is located in the aging section. The reaction tower wall is connected to an ammonia micro-injection unit, which is used to adjust the pH value of the spray section.

5. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 4, characterized in that, The spray section is also equipped with a humidity sensor and a pH detector. Both the humidity sensor and the pH detector are electrically connected to a DCS system. The DCS system controls the ammonia micro-injection unit to adjust the amount of ammonia entering.

6. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 1, characterized in that, A hot air furnace is installed between the gas source section and the fluidized carrier gas inlet, and a filter screen is installed at the gas outlet.

7. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 1, characterized in that, It also includes a product processing system, which comprises a cyclone separator, a fluidized dryer, a vibrating screen and a receiving hopper connected in sequence; the cyclone separator is connected to the fluidized section.

8. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 7, characterized in that, It also includes an exhaust gas processor, which is connected to the exhaust port of the cyclone separator and the top exhaust port of the aging section via gas delivery pipes.

9. The continuous spray fluidized bed coating device for silicon-carbon anode particles according to claim 2, characterized in that, The porous baffle is mirror polished or coated with Teflon, and the atomizing nozzle is made of corrosion-resistant titanium alloy.

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