Silicon-carbon negative electrode material flame spraying internal heating furnace and heating method thereof

Abstract

This invention provides a flame-jet internal heating furnace for silicon-carbon anode materials and its heating method. By employing a three-layer concentric tube structure, the flame descends within the 310s combustion tube and then veers upwards at the bottom of the stainless steel flue gas return tube, forming a unique "U"-shaped flue gas flow path. This significantly extends the residence path and heat exchange time of the high-temperature flue gas within the furnace, ensuring sufficient heat transfer to the silicon nitride heat transfer tube and subsequent uniform radiation to the reaction zone. Specifically, the outermost silicon nitride heat transfer tube utilizes high-purity, high-thermal-conductivity silicon nitride material. This material not only serves as a highly efficient heat transfer medium but, more importantly, acts as a physical barrier, completely preventing contact between the material and all internal metal components. This fundamentally eliminates the contamination of the silicon-carbon anode material by metallic impurities, meeting the purity requirements for high-end material production.

Description

Technical Field

[0001] This invention relates to the field of silicon-carbon anode material production technology, and in particular to a flame-jet internal heating furnace for silicon-carbon anode materials and its heating method. Background Technology

[0002] Silicon-carbon anode materials are considered key materials for next-generation lithium-ion batteries due to their ability to significantly improve battery energy density. Currently, chemical vapor deposition (CVD) is one of the mainstream technologies for preparing silicon-carbon anode materials, the core of which lies in the decomposition of silane gas and its deposition on the pores and surface of porous carbon. However, existing technologies still face severe challenges in terms of production efficiency and product purity. Taking fluidized bed reactors as an example, although they have advantages in gas-solid contact, they are currently limited to a scale of hundreds of kilograms per day due to limitations in equipment materials and scale-up effects, making it difficult to meet the needs of industrial mass production. To overcome this bottleneck, developing a new, efficient, and scalable heating furnace and its method is an urgent problem to be solved in this field.

[0003] In current technological explorations, achieving high-quality industrial production of silicon-carbon anode materials faces three major technical barriers. First, there is the issue of the safety and efficiency of the heat source. The reaction needs to be carried out in an inert gas environment (such as nitrogen) at 600-800℃ to ensure the effective deposition of porous carbon and silane gas. Traditional electric heating methods, while easy to control, are prone to generating electromagnetic eddy currents. Since carbon powder is a good conductor of electricity, electromagnetic eddy currents cause carbon powder to agglomerate in the fluidized bed, severely disrupting the uniformity and stability of fluidization, thus affecting the coating efficiency and quality of silicon. Second, there is the issue of metal contamination. Silicon-carbon anode materials must strictly avoid contact with any metal throughout the entire production process; otherwise, metal ions will diffuse into the product at high temperatures, becoming impurities, leading to battery performance degradation and even safety issues. Existing reactors often have inner walls made of metal (such as stainless steel), making it difficult to fundamentally eliminate metal contamination. Third, there is the issue of atmosphere control. The materials are extremely sensitive to oxygen at high temperatures; once in contact with air, they will oxidize rapidly, not only reducing product purity but also potentially causing combustion or explosion risks. Therefore, operations and material transfers must be carried out under a strictly oxygen-free atmosphere.

[0004] Therefore, there is an urgent need in this field to develop a new type of silicon-carbon anode material production equipment and method. This equipment needs to be able to provide a high-efficiency, uniform and electromagnetically interference-free heat source, while perfectly isolating the material from the inner wall of the metal reactor, and operating stably under strict inert atmosphere protection, thereby solving the problems of low efficiency, poor purity and difficulty in guaranteeing safety in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a flame-jet internal heating furnace for silicon-carbon anode materials and its heating method, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a flame-jet internal heating furnace for silicon-carbon anode materials, comprising a furnace body shell, an inner furnace lining inside the furnace body shell, and insulation material filling the space between the inner furnace lining and the furnace body shell; an upper end cap and a water tank shell are provided on the top of the furnace body, and a lower water tank is fixedly installed inside the upper end cap and the water tank shell; a silicon nitride heat transfer tube with one end closed is arranged axially along the center of the furnace body, the silicon nitride heat transfer tube is floatingly connected to a heat transfer tube support flange assembly via a flange located on its top, and the heat transfer tube support flange assembly is fixedly connected to an upper flange of the lower water tank; a stainless steel flue pipe is coaxially arranged inside the silicon nitride heat transfer tube, the top of the stainless steel flue pipe is floatingly connected to the top of the silicon nitride heat transfer tube via a flange, and its bottom is a closed end for heat transfer with the silicon nitride. The bottom inner wall of the tube maintains a distance; a 310s combustion tube is coaxially arranged inside the stainless steel return flue pipe, the top of the 310s combustion tube is fixed by a combustion tube support flange, and its bottom is open, maintaining a distance from the closed end of the stainless steel return flue pipe; the top inlet end of the 310s combustion tube is connected to a flame injector and a connecting flange for spraying flames, and the flame injector and connecting flange are connected to the upper flange of the upper water tank; a flame injector sleeve is fitted on the outside of the flame injector and connecting flange; the top of the furnace body is also provided with an upper smoke chamber for discharging combustion flue gas, and the upper smoke chamber is connected to the interlayer space between the 310s combustion tube and / or the stainless steel return flue pipe through several jacketed exhaust pipes, the upper end of the jacketed exhaust pipe is connected to the upper smoke chamber, and the outlet of the upper smoke chamber is connected to an exhaust pipe and a flange.

[0008] Preferably, the axial distance between the bottom opening of the 310s combustion tube and the bottom closed end of the stainless steel flue gas return tube is 500-1000mm.

[0009] Preferably, the silicon nitride heat transfer tube is composed of two or three sections sealed together by a silicon nitride tube connecting flange assembly, with a diameter of 300-800mm and a wall thickness of 10-20mm; ceramic fiber gaskets are provided at the flange connection of the silicon nitride heat transfer tube and at the connection with the heat transfer tube support flange assembly.

[0010] Preferably, the upper end cap and water tank shell are detachably connected to the furnace shell via a large flange assembly; the lower water tank is connected to a lower water tank outlet pipe, a water inlet pipe, and a flange; an upper cooling water tank is also provided on the top of the furnace body and around the upper smoke chamber, the upper cooling water tank is connected to an upper water tank outlet pipe, a water inlet pipe, and a flange, the bottom of the upper cooling water tank is provided with an upper water tank lower flange, and the upper water tank lower flange is connected to the combustion tube support flange.

[0011] Preferably, the top of the furnace lining is provided with a furnace lining cover, the center of the furnace lining cover is provided with a circular hole, a heat insulation sleeve is provided at the circular hole, the heat insulation sleeve extends to the upper end cap and the inside of the water tank shell, and corresponds to the top of the silicon nitride heat transfer tube, and the outside of the heat insulation sleeve and the back of the furnace lining cover are filled with heat insulation material.

[0012] Preferably, the upper smoke chamber is located in the central annular area of ​​the upper cooling water tank, the upper cooling water tank is located at the top of the furnace body, its bottom is connected to the combustion tube support flange through the lower flange of the upper water tank, and its top is connected to the burner sleeve.

[0013] Preferably, several jacketed exhaust pipes are evenly distributed between the upper cooling water tank and the combustion pipe support flange, with their upper ends connected to the upper smoke chamber and their lower ends connected to the annular interlayer between the 310s combustion pipe and the stainless steel return smoke pipe.

[0014] Preferably, a reaction zone is formed at the bottom of the furnace body, and an inlet distribution plate for introducing fluidizing gas and silane gas is provided in the reaction zone.

[0015] Preferably, the fuel used for the flamethrower and the connecting flange is natural gas or liquefied petroleum gas.

[0016] The present invention also provides a heating method for a flame-jet internal heating furnace for silicon-carbon anode materials, comprising the following steps: injecting fuel flame into a 310s combustion tube through a flame injector and a connecting flange, the flame propagating downward along the 310s combustion tube; high-temperature flue gas turning at the bottom of the 310s combustion tube and entering the annular jacket between the 310s combustion tube and the stainless steel return flue tube, and flowing upward; the upward-flowing flue gas entering the upper smoke chamber through the jacketed exhaust pipe, and finally being discharged outside the furnace through the exhaust pipe and flange; during this process, the heat of the high-temperature flue gas is transferred to the material in the furnace reaction zone through the stainless steel return flue tube and the silicon nitride heat transfer tube, thereby achieving indirect heating of the material.

[0017] The present invention achieves the following beneficial technical effects compared to the prior art:

[0018] This invention provides a flame-jet internal heating furnace for silicon-carbon anode materials and its heating method, characterized by high thermal efficiency, no electromagnetic interference, and high product purity. It employs a flame-jet internal heating method, radiating heat from the center outwards. Combined with insulation material, this effectively reduces heat loss and significantly improves thermal efficiency. By setting up a three-layer concentric tube structure, the flame descends within the 310s combustion tube and then veers back upwards at the bottom of the stainless steel return flue tube, forming a unique "U"-shaped flue gas flow channel. This greatly extends the residence path and heat exchange time of the high-temperature flue gas within the furnace, ensuring that heat is fully transferred to the silicon nitride heat transfer tube and then uniformly radiated to the reaction zone. In particular, the outermost silicon nitride heat transfer tube uses high-purity, high-thermal-conductivity silicon nitride material. It not only serves as a highly efficient heat transfer medium but, more importantly, acts as a physical barrier, completely blocking contact between the material and all internal metal components (stainless steel return flue tube, 310s combustion tube, etc.), fundamentally eliminating metal impurities from contaminating the silicon-carbon anode material and meeting the purity requirements of high-end material production. Furthermore, the flame heating method using natural gas and other fuels completely avoids the adverse effects of electromagnetic eddy currents generated by electric heating on the fluidization state of conductive carbon powder, ensuring the stability of the fluidized bed and the uniformity of silane deposition. Simultaneously, the closed-end design of the stainless steel flue gas return pipe ensures absolute isolation between the flame and materials even in extreme accidents such as combustion tube rupture, greatly improving equipment safety. The upper and lower water cooling tanks effectively protect the top flange and seals from high-temperature damage, ensuring the long-term stability and reliability of the equipment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the flame-jet internal heating furnace structure for silicon-carbon anode materials provided by the present invention. Detailed Implementation

[0021] Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for 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 limitations on the invention.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] 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.

[0024] The purpose of this invention is to provide a flame-jet internal heating furnace for silicon-carbon anode materials and its heating method, aiming to solve the problems of low heat source efficiency, severe metal contamination, and difficulty in atmosphere control in existing technologies. This equipment, through its unique structural design, achieves a highly efficient, clean, and safe indirect heating method, making it particularly suitable for the production of silicon-carbon anode materials with extremely high requirements for purity and uniformity.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1:

[0027] Please refer to the example below. Figure 1 As shown, Figure 1This is a schematic diagram of the flame-jet internal heating furnace structure for silicon-carbon anode materials provided by the present invention. The flame-jet internal heating furnace for silicon-carbon anode materials of the present invention has a furnace shell 12 that forms the outer contour of the equipment. To ensure stable temperature inside the furnace and reduce heat loss to the environment, a furnace inner lining 21 is provided inside the furnace shell 12, and insulation material 11 is filled in the interlayer space between the furnace inner lining 21 and the furnace shell 12. This double-layer structure, combined with highly efficient insulation material, can confine heat to the furnace chamber to the maximum extent, thereby significantly improving the efficiency of thermal energy utilization.

[0028] At the top of the furnace body, an upper end cap and water tank shell 14 are installed. This upper end cap and water tank shell 14 are detachably and sealed to the furnace body shell 12 via a large flange assembly 26. This connection method ensures the overall structural stability and facilitates equipment installation, inspection, and maintenance. Inside the upper end cap and water tank shell 14, a lower water tank 15 is fixedly installed. This lower water tank 15 is an important component of the equipment's cooling system, and it is connected to a lower water tank outlet pipe 13 and an inlet pipe, as well as a flange 19, for circulating water. During operation, cooling water continuously flows through the lower water tank 15, effectively carrying away heat conducted upwards from below, protecting the top flange and sealing structure from high-temperature damage, and ensuring long-term stable operation of the equipment.

[0029] As the core heating and isolation unit of this invention, a silicon nitride heat transfer tube 23, closed at one end, is arranged axially at the center of the furnace body. This silicon nitride heat transfer tube 23 is the heat transfer medium for the entire heating process and also a key barrier to prevent material from contacting metal components. A flange is provided at the top of the silicon nitride heat transfer tube 23. This flange is not rigidly fixed but is floated by a ceramic fiber gasket 18 and the heat transfer tube support flange assembly 10. This floating installation mode can effectively absorb the stress generated by thermal expansion and prevent the ceramic silicon nitride tube from breaking due to external forces. The heat transfer tube support flange assembly 10 is fixedly connected to the lower water tank upper flange 29 at the bottom of the lower water tank 15, thereby suspending the entire silicon nitride heat transfer tube 23 inside the furnace body.

[0030] Inside the silicon nitride heat transfer tube 23, a stainless steel flue gas return tube 28 is coaxially arranged. The stainless steel flue gas return tube 28 is also made of high-nickel-chromium alloy materials such as 310s stainless steel to withstand long-term erosion from high-temperature flue gas. Its top is equipped with a flange, which is also floated and pressed onto the flange of the silicon nitride heat transfer tube 23 by ceramic fiber gaskets, forming a double-flange floating installation mode. The bottom of the stainless steel flue gas return tube 28 is closed and maintains a certain distance from the bottom inner wall of the silicon nitride heat transfer tube 23. Furthermore, inside the stainless steel flue gas return tube 28, a 310s combustion tube 22 is also coaxially arranged. The top of this 310s combustion tube 22 is fixed by a combustion tube support flange 9, and its bottom is open, maintaining a certain axial distance from the closed end of the stainless steel flue gas return tube 28. This distance is preferably 500-1000mm to form an effective flue gas return space. Through this ingenious three-layer concentric structure of "tube within tube," a unique "U"-shaped flue gas flow channel is formed at the center of the furnace.

[0031] A flamethrower and a connecting flange 1 are connected to the top inlet end of the 310s combustion tube 22. The flamethrower is used to inject flame 25 into the 310s combustion tube 22. The fuel is preferably inexpensive and high-calorific-value natural gas or liquefied petroleum gas. The flamethrower and connecting flange 1 are connected to the upper flange 20 of the upper water tank, and a flamethrower sleeve 2 is fitted on its outside for protection and heat insulation.

[0032] When the flame 25 is injected downwards into the 310s combustion tube 22 and reaches the bottom opening, the high-temperature flue gas is deflected by the closed end of the stainless steel return flue 28, enters the annular interlayer between the 310s combustion tube 22 and the stainless steel return flue 28, and begins to flow upwards. To exhaust this high-temperature flue gas, an upper smoke chamber 3 is provided at the top of the furnace. The upper smoke chamber 3 is not directly connected to the furnace chamber, but is connected to the interlayer space between the 310s combustion tube 22 and the stainless steel return flue 28 through several jacketed exhaust pipes 4. Preferably, there are eight jacketed exhaust pipes 4, evenly distributed between the upper cooling water tank 6 and the combustion tube support flange 9, with their upper ends connected to the upper smoke chamber 3 and their lower ends connected to the aforementioned annular interlayer. The outlet of the upper smoke chamber 3 is connected to an exhaust pipe and a flange 5 for finally discharging the collected flue gas outside the furnace.

[0033] It is worth noting that the upper smoke chamber 3 is located within the central annular area of ​​the upper cooling water tank 6. The upper cooling water tank 6 is installed on top of the furnace body and also serves as part of the cooling system. Its bottom is connected to the combustion tube support flange 9 via the lower flange 8 of the upper water tank, and its top is connected to the burner sleeve 2. The upper cooling water tank 6 is also connected to the upper water tank outlet pipe 24 and the inlet pipe and flange 7, using circulating water to remove heat from the flue gas and the top structure, further protecting precision components such as the burner.

[0034] To facilitate the installation and maintenance of the core heating components, a furnace lining cover 17 is provided on the top of the furnace lining 21. A circular hole is located at the center of the furnace lining cover 17, and an insulating sleeve 16 is installed upwards through this hole. The insulating sleeve 16 extends into the upper end cap and the interior of the water tank shell 14, corresponding to the top of the silicon nitride heat transfer tube 23. When it is necessary to remove the stainless steel flue gas return pipe 28 or the silicon nitride heat transfer tube 23, simply open the upper end cap, and they can be vertically lifted out through the inner hole of the insulating sleeve 16, making the operation very convenient. The exterior of the insulating sleeve 16 and the back of the furnace lining cover 17 are also filled with insulating material 11 to prevent heat loss from the access port.

[0035] During operation, the bottom area of ​​the furnace body constitutes the main reaction zone. An air distribution plate (not shown in the figure) is installed in this zone to uniformly introduce fluidizing gases (such as nitrogen) and reactive gases (such as silane) from the bottom. The material (porous carbon powder) is fluidized under the influence of the airflow. Simultaneously, the heat from the high-temperature flue gas generated by combustion is transferred to the material in the reaction zone through radiation and convection, sequentially passing through the walls of the stainless steel flue gas return pipe 28 and the silicon nitride heat transfer pipe 23. The excellent thermal conductivity of silicon nitride ensures efficient heat transfer, while its good chemical stability and density at high temperatures perfectly prevent direct contact between the material and all internal metal components (including the stainless steel flue gas return pipe 28, the 310s combustion pipe 22, etc.), fundamentally eliminating contamination from metal impurities.

[0036] In summary, the flame-jet internal heating furnace for silicon-carbon anode materials provided by this invention, through its unique structural design, achieves uniform and efficient heating of materials in a metal-free environment. Combined with its corresponding heating method—the process of the flame descending within the 310s combustion tube 22, then turning back upwards at the bottom of the stainless steel flue tube 28, and the heat radiating to the reaction zone through the silicon nitride heat transfer tube 23—it effectively solves the problems of heat source efficiency, metal contamination, and atmosphere control existing in the prior art, providing a reliable technical solution for the large-scale, high-quality production of silicon-carbon anode materials.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0039] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A flame-jet internal heating furnace for silicon-carbon anode materials, comprising a furnace shell (12), characterized in that: The furnace shell (12) is provided with a furnace inner lining (21) inside, and the space between the furnace inner lining (21) and the furnace shell (12) is filled with insulation material (11); the top of the furnace is provided with an upper end cap and a water tank shell (14), and a lower water tank (15) is fixedly provided inside the upper end cap and the water tank shell (14); a silicon nitride heat transfer tube (23) with one end closed is provided along the axial direction at the center of the furnace interior, and the silicon nitride heat transfer tube (23) passes through a [missing information - likely a device or structure] located at its top. The flange and the heat transfer tube support flange assembly (10) are floatingly connected, and the heat transfer tube support flange assembly (10) is fixedly connected to the upper flange (29) of the lower water tank (15); a stainless steel return smoke pipe (28) is coaxially arranged inside the silicon nitride heat transfer tube (23), the top of the stainless steel return smoke pipe (28) is floatingly connected to the top of the silicon nitride heat transfer tube (23) through the flange, and its bottom is a closed end, maintaining a distance from the bottom inner wall of the silicon nitride heat transfer tube (23); The stainless steel return smoke pipe (28) is coaxially provided with a 310s combustion pipe (22). The top of the 310s combustion pipe (22) is fixed by a combustion pipe support flange (9), and its bottom is open, maintaining a distance from the closed end of the stainless steel return smoke pipe (28). The top inlet end of the 310s combustion pipe (22) is connected to a flame injector and a connecting flange (1) for spraying flame (25). The flame injector and the connecting flange (1) are connected to the upper flange (20) of the upper water tank. The flamethrower and connecting flange (1) are fitted with a flamethrower sleeve (2) on the outside; the top of the furnace body is also provided with an upper smoke chamber (3) for exhausting combustion flue gas. The upper smoke chamber (3) is connected to the interlayer space between the 310s combustion pipe (22) and / or stainless steel return smoke pipe (28) through several jacketed exhaust pipes (4). The upper end of the jacketed exhaust pipe (4) is connected to the upper smoke chamber (3). The outlet of the upper smoke chamber (3) is connected to an exhaust pipe and a flange (5).

2. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The axial distance between the bottom opening of the 310s combustion tube (22) and the bottom closed end of the stainless steel flue gas return tube (28) is 500-1000mm.

3. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The silicon nitride heat transfer tube (23) is formed by sealing two or three sections connected by a silicon nitride tube connecting flange assembly (27). Its diameter is 300-800mm and its wall thickness is 10-20mm. Ceramic fiber gaskets (18) are provided at the flange connection of the silicon nitride heat transfer tube (23) and at the connection with the heat transfer tube support flange assembly (10).

4. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The upper end cap and water tank shell (14) are detachably connected to the furnace shell (12) via a large flange assembly (26); the lower water tank (15) is connected to a lower water tank outlet pipe (13), a water inlet pipe, and a flange (19); an upper cooling water tank (6) is also provided on the top of the furnace body and around the upper smoke chamber (3), the upper cooling water tank (6) is connected to an upper water tank outlet pipe (24), a water inlet pipe, and a flange (7), the bottom of the upper cooling water tank (6) is provided with an upper water tank lower flange (8), and the upper water tank lower flange (8) is connected to a combustion tube support flange (9).

5. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The furnace lining (21) is provided with a furnace lining cover (17) at the top. A circular hole is provided in the center of the furnace lining cover (17). A heat insulation sleeve (16) is provided at the circular hole. The heat insulation sleeve (16) extends to the upper end cap and the inside of the water tank shell (14) and corresponds to the top of the silicon nitride heat transfer tube (23). The outside of the heat insulation sleeve (16) and the back of the furnace lining cover (17) are filled with heat insulation material (11).

6. The silicon-carbon anode material flame-jet internal heating furnace according to claim 4, characterized in that: The upper smoke chamber (3) is located in the central annular area of ​​the upper cooling water tank (6). The upper cooling water tank (6) is located at the top of the furnace body. Its bottom is connected to the combustion tube support flange (9) through the lower flange (8) of the upper water tank, and its top is connected to the burner sleeve (2).

7. The silicon-carbon anode material flame-jet internal heating furnace according to claim 6, characterized in that: Several jacketed exhaust pipes (4) are evenly distributed between the upper cooling water tank (6) and the combustion pipe support flange (9), with their upper ends connected to the upper smoke chamber (3) and their lower ends connected to the annular interlayer between the 310s combustion pipe (22) and the stainless steel return smoke pipe (28).

8. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The bottom of the furnace body forms a reaction zone, and an inlet distribution plate for introducing fluidizing gas and silane gas is provided in the reaction zone.

9. The silicon-carbon anode material flame-jet internal heating furnace according to claim 1, characterized in that: The fuel used for the flamethrower and connecting flange (1) is natural gas or liquefied petroleum gas.

10. A heating method for a flame-jet internal heating furnace for silicon-carbon anode materials, comprising the flame-jet internal heating furnace for silicon-carbon anode materials as described in any one of claims 1-9, characterized in that, Includes the following steps: Fuel flame (25) is injected into the 310s combustion tube (22) through the burner and connecting flange (1), and the flame (25) spreads downward along the 310s combustion tube (22); the high-temperature flue gas turns at the bottom of the 310s combustion tube (22) and enters the annular jacket between the 310s combustion tube (22) and the stainless steel return flue (28), and flows upward; the upward-flowing flue gas enters the upper smoke chamber (3) through the jacketed exhaust pipe (4), and is finally discharged outside the furnace through the exhaust pipe and flange (5); in this process, the heat of the high-temperature flue gas is transferred to the material in the furnace reaction zone through the stainless steel return flue (28) and the silicon nitride heat transfer pipe (23), thereby achieving indirect heating of the material.

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