A silicon-carbon negative electrode rotary furnace CVD coating device

Abstract

The present application relates to lithium battery silicon-carbon negative electrode material preparation equipment technical field, specifically provides a kind of silicon-carbon negative electrode rotary furnace CVD coating equipment, including equipment rack, rotary furnace tube, heat preservation hearth, power rotating mechanism, gas adding system, heating system and cooling system, rotary furnace tube is rotationally connected with equipment rack by power rotating mechanism, rotary furnace tube is overall inclined and the feeding end of rotary furnace tube is higher than discharge end, heat preservation hearth is coated and installed outside rotary furnace tube, heat preservation hearth is fixedly connected with equipment rack, gas adding system is used to transport multiple gases into rotary furnace tube, heating system is used to heat rotary furnace tube, cooling system is used to cool rotary furnace tube, in gas inlet end, various process gases are first completed uniform mixing then are sent into furnace by gas guide pipe, cooperate with arc-shaped material lifting plate to form material overturning mechanism, realize that mixed gas and powder raw material are contacted fully in all directions, effectively improve process gas utilization and overall production efficiency.

Description

Technical Field

[0001] This invention relates to the field of equipment technology for preparing silicon-carbon anode materials for lithium batteries, and particularly to a silicon-carbon anode rotary furnace CVD coating equipment. Background Technology

[0002] Silicon-carbon anodes for lithium-ion batteries have become core anode materials for high-energy-density power batteries due to their high theoretical capacity and low lithium intercalation platform. The production process of silicon-carbon anodes generally employs CVD (chemical vapor deposition) technology, utilizing a rotary kiln to complete carbon layer coating and modification under a high-temperature, inert atmosphere.

[0003] In the typical process of preparing silicon-carbon anodes, a rotary kiln CVD coating equipment is used to perform high-temperature vapor phase coating modification on silicon-carbon powder. Methane, acetylene and high-purity inert protective gas are introduced into the equipment. The material is continuously tumbled and mixed by the rotation of the furnace body. Vapor phase deposition and surface coating reaction are achieved in a segmented high-temperature environment. After the reaction is completed, the powder is cooled in a sealed environment and demagnetized by sieving to obtain the finished silicon-carbon anode material.

[0004] Currently, most traditional silicon-carbon anode CVD rotary furnace equipment uses simple sealing with ordinary end caps, single temperature control of the entire furnace chamber, and no dedicated material lifting and pushing structure in the straight cylinder inside the furnace.

[0005] This results in poor sealing at both ends of the furnace body, excessive oxygen content inside the furnace, and easy oxidation and failure of silicon-carbon powder under high temperature conditions. At the same time, the airflow distribution inside the furnace is disordered, materials are prone to accumulating and clumping, and independent temperature control of multiple temperature zones cannot be achieved. This not only reduces the uniformity of silicon-carbon anode coating and battery cycle life, but also poses a safety hazard of flammable and explosive process gas leakage, resulting in low production yield and high equipment energy consumption.

[0006] In traditional equipment, the gas guiding structure and the material lifting structure are independent. The gas is directly introduced into the furnace without premixing, resulting in poor gas-material mixing and low gas utilization. The gas injection direction and orifice design are not designed in conjunction with the material movement state, which easily forms a stable gas boundary layer on the surface of powder particles, reducing the efficiency of vapor deposition reaction and easily generating by-products such as free silicon powder and carbon powder. At the same time, the general-purpose gas guiding pipe is not designed differently for different reaction temperature zones and different reaction gases. Gas crossflow and side reactions due to reactant mixing are likely to occur in different temperature zones, resulting in poor overall process matching and product consistency of the equipment. Summary of the Invention

[0007] To address the problems of existing traditional silicon-carbon anode CVD rotary furnace equipment, which mostly uses simple sealing with ordinary end caps, single temperature control of the entire furnace chamber, and lack of a dedicated material lifting and pushing structure in the straight cylinder inside the furnace, this invention provides a silicon-carbon anode rotary furnace CVD coating equipment.

[0008] The technical solution adopted by this invention to solve its technical problem is: a silicon-carbon anode rotary CVD coating device, including a frame, a rotary furnace tube, a heat-insulating furnace chamber, a power rotation mechanism, a gas injection system, a heating system, and a cooling system. The rotary furnace tube is rotatably connected to the frame via the power rotation mechanism. The rotary furnace tube is inclined as a whole, with the feed end higher than the discharge end. The heat-insulating furnace chamber is installed around the rotary furnace tube and is coaxial with the rotary furnace tube. The heat-insulating furnace chamber is fixedly connected to the frame. The gas injection system is used to deliver various gases into the rotary furnace tube. The heating system is used to heat the rotary furnace tube. The cooling system is used to cool the rotary furnace tube.

[0009] Preferably, the equipment frame includes an upper frame, a lower frame, and a frame lifting module. One end of the upper frame is rotatably connected to the top of the lower frame, and the other end of the upper frame overlaps with the lower frame. The frame lifting module includes a lifting mechanism, the lower end of which is rotatably connected to the lower frame, and the upper end of which is rotatably connected to the upper frame. The frame lifting module is used to adjust the tilt angle of the rotary furnace tube.

[0010] Preferably, multiple sets of arc-shaped lifting plates are fixedly installed on the inner wall of the rotary furnace tube; the arc-shaped lifting plates are evenly and staggered along the circumference of the rotary furnace tube, the curvature of the plate surface of the arc-shaped lifting plate is R2000~R2500, the angle between the plate surface of the arc-shaped lifting plate and the radial direction of the furnace tube is set to 30°~60°, and a gas guide pipe is provided axially inside the rotary furnace tube, and the gas inlet end of the gas guide pipe is connected to the gas injection system.

[0011] Preferably, a mixing mechanism is fixed inside the air inlet end of the air guide pipe. The mixing mechanism includes a fixed bracket, an air guide cone, an air guide hood, an air collecting hopper, a fan wheel, a sealing ring, a one-way valve plate, a valve stem, and a backup pressure spring. The fixed bracket is vertically fixed to the inner wall of the air guide pipe. The air guide cone is rotatably mounted on the front end of the fixed bracket. Multiple blades are fixed at equal intervals on the surface of the air guide cone. The air guide hood is fixed to the rear end of the fixed bracket. The air collecting hopper is fixed inside the air guide hood and located at the front end of the air guide hood. The fan wheel is fixed to the rear end of the air collecting hopper. The rear end of the fan wheel is closed by an end plate and has an opening at the front end of the fan wheel that communicates with the air collecting hopper. The sealing ring is fixed to the rear end of the air guide hood. The valve stem is slidably mounted on the rear end of the fan wheel and vertically passes through the end plate. The two ends of the backup pressure spring are respectively connected to one end of the valve stem and the end plate of the fan wheel. The one-way valve plate is fixed to the other end of the valve stem and can fit against the sealing ring.

[0012] Preferably, the air guide pipe is provided with multiple sets of nozzles along the axial direction, and each set of nozzles is arranged in a ring at equal intervals along the circumference of the air guide pipe, with the distance between the nozzles decreasing sequentially from the air inlet end to the outlet end.

[0013] Preferably, the heat-insulating furnace is configured with three stages during operation: preheating, heating, and heat preservation. Different gases are introduced into the gas guide pipe in proportion during each of the three stages.

[0014] Preferably, the power rotation mechanism includes a transmission support wheel, a rotating support, a transmission sprocket, and a reduction motor. The transmission support wheel and the rotating support are respectively fixed at the top two ends of the equipment frame. The feed end of the rotary furnace tube is rotatably connected to the rotating support. The discharge end of the rotary furnace tube is rolled on the transmission support wheel. The transmission sprocket is coaxially fixed to the outer wall of one end of the rotary furnace tube. The output shaft of the reduction motor is connected to the transmission sprocket via a chain.

[0015] Preferably, the heating system includes multiple sets of heating modules and multiple sets of temperature control thermocouples. The multiple sets of heating modules are evenly distributed along the interior of the heat-insulating furnace chamber, and the multiple sets of temperature control thermocouples are interspersed on the heat-insulating furnace chamber.

[0016] Preferably, the gas dosing system includes a gas valve assembly, a pressure acquisition module, a staged air intake rotary joint, and a dynamic sealing assembly. The gas valve assembly is fixed on the equipment frame and connected to the air intake pipe. The pressure acquisition module is connected to the gas valve assembly and the staged air intake rotary joint through pipes. The staged air intake rotary joint and the air guide pipe are rotatably sealed together by the dynamic sealing assembly.

[0017] Preferably, the dynamic sealing assembly includes a sealing housing and a sealing gasket, the sealing housing being connected to the rotary furnace tube, and the sealing gasket being disposed between the mating end faces of the sealing housing and the rotary furnace tube.

[0018] The beneficial effects of this invention are as follows: First, the circumferentially distributed arc-shaped lifting plates are set on the inner wall of the furnace. Relying on the inclined arrangement and rotation of the furnace tube, the material can be continuously rolled, dispersed and slowly pushed, effectively avoiding the accumulation and agglomeration of powder materials and significantly improving the overall uniformity of silicon-carbon anode vapor deposition coating. The arc-shaped lifting plates adopt a specific curvature and installation angle, which can completely eliminate the dead zone of ultrafine powder flow. The material conveying and turning effect is better than that of conventional straight plate lifting structures.

[0019] Secondly, a premixing structure is set at the air inlet, so that various process gases are first uniformly mixed and then sent into the furnace through the gas guide pipe. Combined with the material turning mechanism composed of arc-shaped lifting plates, the mixed gas and powder raw materials are fully contacted in all directions, which effectively improves the utilization rate of process gases and the overall production efficiency.

[0020] Third, the air guide pipe and the arc-shaped lifting plate are spatially coupled, and the nozzles are oriented towards the powder flow area. Combined with the gradient opening structure, this not only solves the problem of uneven air pressure in long pipelines, but also breaks the gas boundary layer on the powder surface, effectively improving the vapor deposition reaction rate, reducing by-products such as free carbon powder, and significantly improving the raw material utilization rate.

[0021] Fourth, the gas guide pipes are designed with differentiated structures for the three different reaction temperature zones, and a flow guiding and gas blocking structure is set at the junction of the temperature zones. This can match the different cracking kinetic characteristics of methane and acetylene, while blocking the crossflow of reaction gases, preventing the mixing of different reactants and the generation of side reactions, and greatly improving the consistency of product batches.

[0022] Fifth, the use of high-temperature resistant sealing gaskets combined with an inert gas positive pressure sealing structure provides good sealing fit and strong airtight isolation capability, which can effectively control the oxygen content in the furnace to an extremely low level, thus preventing the carbon powder from oxidizing and failing under high-temperature process conditions.

[0023] Sixth, the heat preservation furnace adopts a three-section independent temperature zone structure, which can realize precise and independent control of different process temperatures such as preheating, heating and heat preservation. A single unit can complete the continuous carbon layer coating operation in one integrated manner, with strong process adaptability and stable and reliable operation.

[0024] Seventh, the furnace tube tilt angle, rotation speed and gas guide structure parameters are linked and matched to form an optimal working condition. Unlike the simple superposition of conventional equipment, the process is more targeted. According to actual measurement, the coating uniformity of silicon-carbon anode materials prepared by this equipment is reduced by more than 60%, the first coulombic efficiency of the product is improved by 2%~3%, and the overall yield of the production line is improved by 4%~6%.

[0025] The equipment has a compact overall layout and reasonable support and limit. During operation, the furnace body rotates smoothly without deviation or shaking. It has high operational stability under long-term high-temperature conditions and is easy to maintain. Attached Figure Description

[0026] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the optimal embodiment of the silicon-carbon anode rotary furnace CVD coating equipment of the present invention; Figure 2 This is a schematic diagram of the dynamic sealing assembly of a silicon-carbon anode rotary furnace CVD coating device according to the present invention; Figure 3 This is a schematic diagram of the gas valve group of a silicon-carbon anode rotary furnace CVD coating equipment according to the present invention; Figure 4 This is a schematic diagram of the structure of the heat-insulating furnace chamber of a silicon-carbon anode rotary CVD coating device according to the present invention; Figure 5 This is a schematic diagram of the gas guide pipe of a silicon-carbon anode rotary furnace CVD coating device according to the present invention; Figure 6 This is a schematic diagram of the nozzle structure of a silicon-carbon anode rotary furnace CVD coating device according to the present invention; Figure 7 This is a schematic diagram of the gas guide cone of a silicon-carbon anode rotary furnace CVD coating device according to the present invention; Figure 8 This is a schematic diagram of the structure of a one-way valve plate of a silicon-carbon anode rotary furnace CVD coating device according to the present invention.

[0028] Reference numerals: 1. Equipment frame; 2. Rotary furnace tube; 3. Insulated furnace chamber; 4. Power rotation mechanism; 5. Gas dosing system; 6. Heating system; 7. Cooling system; 8. Upper frame; 9. Lower frame; 10. Lifting mechanism; 11. Gas guide pipe; 12. Mixing mechanism; 13. Fixed support; 14. Gas guide cone; 15. Gas guide hood; 16. Gas collection hopper; 17. Fan wheel; 18. Sealing ring; 19. One-way valve plate; 20. Valve stem; 21. Backup pressure spring; 22. End plate; 23. Spray hole; 24. Transmission support wheel; 25. Rotating support; 26. Transmission sprocket; 27. Gear motor; 28. Heating module; 29. ​​Temperature control thermocouple; 30. Gas valve assembly; 31. Pressure acquisition module; 32. Staged air intake rotary joint; 33. Dynamic sealing assembly; 34. Sealing shell. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] like Figures 1 to 8As shown, this invention provides an embodiment of a silicon-carbon anode rotary CVD coating equipment, including an equipment frame 1, a rotary furnace tube 2, an insulated furnace chamber 3, a power rotation mechanism 4, a gas feeding system 5, a heating system 6, and a cooling system 7. The rotary furnace tube 2 is rotatably connected to the equipment frame 1 via the power rotation mechanism 4. The rotary furnace tube 2 is inclined as a whole, with the feed end of the rotary furnace tube 2 higher than the discharge end. The adjustable angle of the overall installation tilt is 0~14°. The insulated furnace chamber 3 is installed around the rotary furnace tube 2 and is coaxial with the rotary furnace tube 2. The insulated furnace chamber 3 is fixedly connected to the equipment frame 1. The gas feeding system 5 is used to deliver various gases into the rotary furnace tube 2. The heating system 6 is used to heat the rotary furnace tube 2. The cooling system 7 is used to cool the rotary furnace tube 2. The cooling system 7 uses a fan to blow air onto the rotary furnace tube 2 through a pipe to achieve cooling.

[0032] The equipment frame 1 includes an upper frame 8, a lower frame 9, and a frame lifting module. One end of the upper frame 8 is rotatably connected to the top of the lower frame 9, and the other end of the upper frame 8 overlaps with the lower frame 9. The frame lifting module includes a lifting mechanism 10. The lower end of the lifting mechanism 10 is rotatably connected to the lower frame 9, and the upper end of the lifting mechanism 10 is rotatably connected to the upper frame 8. The frame lifting module is used to adjust the tilt angle of the rotary furnace tube 2.

[0033] Multiple sets of arc-shaped lifting plates are fixedly installed on the inner wall of the rotary furnace tube 2. The arc-shaped lifting plates are evenly and staggered around the circumference of the rotary furnace tube 2. The curvature of the plate surface of the arc-shaped lifting plate is R2000~R2500. The angle between the plate surface of the arc-shaped lifting plate and the radial direction of the furnace tube is set to 30°~60°. This angle can be adapted to the characteristics of silicon carbide ultrafine powder, eliminate dead zones in material flow, and avoid local accumulation of powder. The arc-shaped lifting plates act as a turning mechanism to continuously turn the material, so that the sprayed mixed gas and the powder raw material can fully contact and mix, which greatly improves the utilization rate of process gas and the overall production efficiency.

[0034] The rotary furnace tube 2 is provided with a gas guide pipe 11 along the axial direction inside. The gas inlet end of the gas guide pipe 11 is connected to the gas feeding system 5 to uniformly transport acetylene and inert gas into the rotary furnace tube 2.

[0035] The gas distribution pipe 11 is provided with multiple sets of nozzles 23 arranged axially. Each set of nozzles 23 is arranged in a ring at equal intervals along the circumference of the gas distribution pipe 11. The spacing between the nozzles 23 decreases sequentially from the inlet end to the outlet end. The nozzle diameter of the gas distribution pipe is selected to be 2-3 mm to avoid clogging by carbon black generated by pyrolysis if the diameter is too small. When the flow rate is lower than a certain range, pyrolysis and coking will occur at the orifice of the nozzle 23. It is necessary to strictly control the orifice diameter and the gas outlet flow rate, while taking into account the uniformity of gas distribution. Therefore, the gas flow rate is controlled within the range of 8-15 m / s for different process requirements.

[0036] The arc-shaped lifting plate rotates with the rotary furnace tube 2, causing the material to continuously tumble and scatter. The material is slowly conveyed forward by relying on the tilt angle of the rotary furnace tube 2 itself, avoiding powder accumulation and agglomeration, and improving the uniformity of gas phase coating.

[0037] The air guide pipe 11 and the arc-shaped lifting plate form a spatially coordinated structure. The nozzles 23 of the air guide pipe 11 are all inclined and arranged towards the powder curtain raised by the arc-shaped lifting plate, spraying in the direction of material flow and precisely targeting the powder waterfall formed by the rotation of the lifting plate. The lifting plate, together with the inclined air guide pipe 11, can actively break the gas boundary layer on the surface of powder particles, greatly improve the contact efficiency between acetylene and the powder surface, accelerate the vapor deposition rate, and at the same time suppress free nucleation of the gas phase, reducing the generation of ineffective by-products such as free silicon powder and carbon powder. The arc-shaped lifting plate continuously disturbs the material, allowing the mixed gas to repeatedly and fully contact the raw materials, further improving the utilization rate of the mixed gas and production efficiency.

[0038] A mixing mechanism 12 is also fixed inside the air inlet end of the air duct 11. The mixing mechanism 12 includes a fixed bracket 13, an air guide cone 14, an air guide hood 15, an air collecting bucket 16, a fan wheel 17, a sealing ring 18, a one-way valve plate 19, a valve stem 20, and a pressure spring 21. The fixed bracket 13 is vertically fixed to the inner wall of the air duct 11. The air guide cone 14 is rotatably mounted on the front end of the fixed bracket 13. Multiple blades are fixed at equal intervals on the surface of the air guide cone 14. The air guide hood 15 is fixed to the rear end of the fixed bracket 13, and the air collecting bucket 16 is fixed to the air guide hood 16. The impeller 17 is fixed to the rear end of the air collecting hopper 16 and is located at the front end of the air guide hood 15. The rear end of the impeller 17 is closed by the end plate 22 and an opening communicating with the air collecting hopper 16 is provided at the front end of the impeller 17. The sealing ring 18 is fixed to the rear end of the air guide hood 15. The valve stem 20 is slidably installed at the rear end of the impeller 17 and passes vertically through the end plate 22. The two ends of the pressure spring 21 are respectively connected to one end of the valve stem 20 and the end plate 22 of the impeller 17. The one-way valve plate 19 is fixed to the other end of the valve stem 20 and can fit with the sealing ring 18.

[0039] After the gas dosing system 5 sends acetylene and inert gas into the gas delivery pipe 11, it first comes into contact with the mixing mechanism 12. When the gas pressure is greater than the set value, the one-way valve plate 19 is opened by the gas pressure, so that the mixed gas with qualified pressure can be smoothly and stably sprayed out from the nozzle 23 of the gas delivery pipe 11, avoiding the gas spray velocity of the nozzle 23 being too small due to low gas pressure.

[0040] When methane and inert gas flow through the guide cone 14, they push the blades to move, causing the guide cone 14 to rotate. This rotation disperses the acetylene and inert gas, initially mixing them to form a mixed gas. This mixed gas enters the guide hood 15 and is guided into the impeller 17 by the gas collecting hopper 16. Finally, it flows from the impeller 17 to the one-way valve plate 19. During this process, the gas flow direction changes multiple times to ensure that the acetylene and inert gas are thoroughly mixed again. The inert gas and acetylene are thoroughly mixed, with the relative fluctuation of the acetylene concentration controlled within ±3.5%. This ensures uniform carbon coating and avoids localized carbon buildup.

[0041] The heat-insulating furnace 3 is set up with three stages during operation: preheating, heating, and heat preservation. Different gases are introduced into the gas pipe 11 in proportion to each of the three stages. Specifically, nitrogen is introduced through the gas pipe 11 during the preheating and heating stages, and nitrogen and acetylene are introduced during the heat preservation stage.

[0042] The coated high-temperature material is discharged from the dynamic sealing assembly 33 at the discharge end of the rotary furnace tube 2 and transferred to an external independent cooling and screening device to complete cooling and impurity removal. The exhaust gas is centrally collected and uniformly treated to achieve safe and continuous production.

[0043] The power rotation mechanism 4 includes a transmission support wheel 24, a rotating support 25, a transmission sprocket 26, and a reduction motor 27. The transmission support wheel 24 and the rotating support 25 are respectively fixed at the top two ends of the equipment frame 1. The feed end of the rotary furnace tube 2 is rotatably connected to the rotating support 25, and the discharge end of the rotary furnace tube 2 is rolled on the transmission support wheel 24 to form stable support and radial limit, so as to prevent the rotary furnace tube 2 from shifting or shaking during long-term rotation at high temperature, and to ensure the stability of equipment operation. The transmission sprocket 26 is coaxially fixed on the outer wall of one end of the rotary furnace tube 2, and the output shaft of the reduction motor 27 is connected to the transmission sprocket 26 through a chain.

[0044] The working speed of the rotary furnace tube 2 is set to 0.5 r / min to 2.0 r / min. The furnace tube tilt angle, rotation speed and the parameters of the nozzle 23 of the gas guide pipe 11 are linked and matched. The three work together to ensure that the vapor deposition reaction is in the optimal working condition, which is used to support and drive the rotary furnace tube 2 to rotate at a low speed and uniform speed.

[0045] The heating system 6 includes multiple heating modules 28 and multiple temperature control thermocouples 29. The multiple heating modules 28 are evenly arranged along the inside of the heat preservation furnace 3, and the multiple temperature control thermocouples 29 are interspersed on the heat preservation furnace 3. The heating modules 28 are electrically heated. When the temperature is too high, the fan of the cooling system 7 is started to cool down.

[0046] The gas dosing system 5 includes a gas valve assembly 30, a pressure acquisition module 31, a staged air intake rotary joint 32, and a dynamic sealing assembly 33. The gas valve assembly 30 is fixed on the equipment frame 1 and connected to the air intake pipe. The pressure acquisition module 31 is connected to the gas valve assembly 30 and the staged air intake rotary joint 32 through pipes. The staged air intake rotary joint 32 and the air guide pipe 11 are connected by a rotary seal through the dynamic sealing assembly 33.

[0047] The gas supply valve assembly 30 continuously supplies high-purity inert protective gas through the staged air intake rotary joint 32, which, together with the dynamic sealing assembly 33, forms a positive pressure seal on the end face, preventing outside air from entering the furnace and preventing the silicon carbide powder from oxidizing and deteriorating under high-temperature conditions.

[0048] The dynamic sealing assembly 33 includes a sealing housing 34 and a sealing gasket. The sealing housing 34 is connected to the rotary furnace tube 2, and the sealing gasket is disposed between the mating end face of the sealing housing 34 and the rotary furnace tube 2.

[0049] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above are only preferred embodiments of this application. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A silicon-carbon anode rotary furnace CVD coating device, characterized in that: The equipment includes a frame (1), a rotary furnace tube (2), an insulated furnace chamber (3), a power rotation mechanism (4), a gas injection system (5), a heating system (6), and a cooling system (7). The rotary furnace tube (2) is rotatably connected to the frame (1) via the power rotation mechanism (4). The rotary furnace tube (2) is inclined as a whole, and the feed end of the rotary furnace tube (2) is higher than the discharge end. The insulated furnace chamber (3) is installed around the rotary furnace tube (2) and is coaxial with the rotary furnace tube (2). The insulated furnace chamber (3) is fixedly connected to the frame (1). The gas injection system (5) is used to deliver various gases into the rotary furnace tube (2). The heating system (6) is used to heat the rotary furnace tube (2). The cooling system (7) is used to cool the rotary furnace tube (2).

2. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 1, characterized in that: The equipment frame (1) includes an upper frame (8), a lower frame (9) and a frame lifting module. One end of the upper frame (8) is rotatably connected to the top of the lower frame (9), and the other end of the upper frame (8) overlaps with the lower frame (9). The frame lifting module includes a lifting mechanism (10). The lower end of the lifting mechanism (10) is rotatably connected to the lower frame (9), and the upper end of the lifting mechanism (10) is rotatably connected to the upper frame (8). The frame lifting module is used to adjust the tilt angle of the rotary furnace tube (2).

3. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 1, characterized in that: Multiple sets of arc-shaped lifting plates are fixedly installed on the inner wall of the rotary furnace tube (2); The arc-shaped lifting plates are evenly and staggered along the circumference of the rotary furnace tube (2). The curvature of the arc-shaped lifting plate is R2000~R2500. The angle between the surface of the arc-shaped lifting plate and the radial direction of the furnace tube is set to 30°~60°. The rotary furnace tube (2) is provided with a gas guide pipe (11) along the axial direction. The gas inlet end of the gas guide pipe (11) is connected to the gas feeding system (5).

4. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 3, characterized in that: A mixing mechanism (12) is fixed inside the air inlet end of the air guide pipe (11). The mixing mechanism (12) includes a fixed bracket (13), an air guide cone (14), an air guide hood (15), an air collecting bucket (16), a windmill (17), a sealing ring (18), a one-way valve plate (19), a valve stem (20), and a pressure spring (21). The fixed bracket (13) is vertically fixed to the inner wall of the air guide pipe (11). The air guide cone (14) is rotatably installed at the front end of the fixed bracket (13). Multiple blades are fixed at equal intervals on the surface of the air guide cone (14). The air guide hood (15) is fixed at the rear end of the fixed bracket (13). The air collecting bucket (16) is fixed inside the air guide hood (15) and positioned within it. At the front end of the air guide hood (15), the impeller (17) is fixed at the rear end of the air collecting hopper (16). The rear end of the impeller (17) is closed by the end plate (22) and an opening communicating with the air collecting hopper (16) is provided at the front end of the impeller (17). The sealing ring (18) is fixed at the rear end of the air guide hood (15). The valve stem (20) is slidably installed at the rear end of the impeller (17) and passes vertically through the end plate (22). The two ends of the pressure spring (21) are respectively connected to one end of the valve stem (20) and the end plate (22) of the impeller (17). The one-way valve plate (19) is fixed at the other end of the valve stem (20) and can fit against the sealing ring (18).

5. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 3, characterized in that: The air guide pipe (11) is provided with multiple sets of nozzles (23) along the axial direction. Each set of nozzles (23) is arranged in a ring with equal spacing along the circumference of the air guide pipe (11). The distance between the nozzles (23) from the air inlet end to the outlet end decreases sequentially.

6. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 4, characterized in that: The heat-insulating furnace (3) is set up with three stages when it is working: preheating, heating and heat preservation. The gas guide pipe (11) introduces different gases in proportion to each of the three stages.

7. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 1, characterized in that: The power rotation mechanism (4) includes a transmission support wheel (24), a rotating support (25), a transmission sprocket (26), and a reduction motor (27). The transmission support wheel (24) and the rotating support (25) are respectively fixed at the top two ends of the equipment frame (1). The feed end of the rotary furnace tube (2) is rotatably connected to the rotating support (25). The discharge end of the rotary furnace tube (2) is rolled on the transmission support wheel (24). The transmission sprocket (26) is coaxially fixed on the outer wall of one end of the rotary furnace tube (2). The output shaft of the reduction motor (27) is connected to the transmission sprocket (26) via a chain.

8. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 1, characterized in that: The heating system (6) includes multiple heating modules (28) and multiple temperature control thermocouples (29). The multiple heating modules (28) are evenly arranged along the interior of the heat-insulating furnace (3), and the multiple temperature control thermocouples (29) are interspersed on the heat-insulating furnace (3).

9. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 3, characterized in that: The gas dosing system (5) includes a gas valve assembly (30), a pressure acquisition module (31), a staged air intake rotary joint (32), and a dynamic sealing assembly (33). The gas valve assembly (30) is fixed on the equipment frame (1) and connected to the air intake pipe. The pressure acquisition module (31) is connected to the gas valve assembly (30) and the staged air intake rotary joint (32) through pipes respectively. The staged air intake rotary joint (32) and the air guide pipe (11) are rotated and sealed by the dynamic sealing assembly (33).

10. The silicon-carbon anode rotary furnace CVD coating equipment as described in claim 9, characterized in that: The dynamic sealing assembly (33) includes a sealing housing (34) and a sealing gasket. The sealing housing (34) is connected to the rotary furnace tube (2), and the sealing gasket is disposed between the sealing housing (34) and the mating end face of the rotary furnace tube (2).

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