A rapid cooling graphitization system and method for negative electrode materials

Abstract

This invention discloses a rapid cooling graphitization system and method for negative electrode materials, including an external gas supply unit, a control unit, a temperature measuring unit, and an Atchison box furnace with a vent pipe arranged at the bottom of the furnace. The vent pipe has vent holes spaced along its axial direction, connecting to the interior of the Atchison box furnace. The external gas supply unit has a nitrogen source, which is connected to the vent pipe via a pipeline to introduce nitrogen into the Atchison box furnace. After the Atchison box furnace is powered off, when the temperature measuring unit detects that the furnace temperature has dropped to a first set temperature, the control unit activates the external gas supply unit to introduce nitrogen into the furnace for forced cooling of the furnace core. By pre-installing a vent pipe with vent holes at the bottom of the furnace, nitrogen is directly introduced into the bottom area of ​​the furnace core where heat accumulation is most severe. Utilizing nitrogen heat exchange overcomes the problems of poor heat dissipation and difficulty in heat dissipation caused by the dense furnace core and heat storage in the surrounding insulation layer of traditional Atchison box furnaces.

Description

Technical Field

[0001] This invention relates to the field of graphitization processing technology, and in particular to a rapid cooling graphitization system and method for negative electrode materials. Background Technology

[0002] With the rapid development of new energy vehicles and the energy storage industry, the market demand for lithium-ion battery anode materials (especially artificial graphite) continues to grow. In the production process of artificial graphite anode materials, graphitization is the core process that determines the final performance of the material, and it is also the most energy-intensive and longest-cycle stage. Currently, the mainstream graphitization equipment in the industry is the Atchison box furnace. Although this type of furnace is technologically mature and has a large single-furnace capacity, it has long suffered from the inherent characteristic of "rapid heating and slow cooling," which severely limits its production cycle due to the cooling stage. Actual production data shows that the cooling cycle of a box furnace using natural cooling can be as long as 40 to 43 days, greatly limiting equipment turnover and production efficiency.

[0003] The main reasons for the aforementioned cooling bottleneck are: First, the furnace core of the box furnace has a large cross-section, and after high-temperature graphitization, the material undergoes dense sedimentation, making it difficult for internal heat to be effectively transferred to the surface of the furnace core through conduction; Second, in order to ensure heating efficiency, multiple layers of heat-insulating materials (such as carbon black insulation layers and refractory bricks) are installed at the bottom and sides of the furnace body, which play a good role in heat preservation during the heating stage, but during the cooling stage, these heat-storing materials will release heat back to the furnace core, forming a situation of "poor heat dissipation and difficulty in heat accumulation".

[0004] To shorten the cooling cycle, existing technologies have attempted to introduce external auxiliary cooling methods, but all have significant limitations or safety hazards. For example, when using water cooling, the furnace temperature at the end of graphitization reaches approximately 2800℃, and direct water spraying or water mist can easily trigger a flash explosion or even a furnace blowout. Furthermore, the decomposition of water at high temperatures or the introduction of oxygen can cause oxidation reactions with the anode material, leading to deterioration of key performance indicators such as the specific surface area of ​​the product and reducing the yield. Similarly, when using external fans for forced air cooling, excessive airflow can easily blow away surface insulation material and other materials, causing dust and material loss. Simultaneously, the anode material and carbonaceous components inside the furnace are highly susceptible to oxidation when exposed to air at high temperatures (especially above 450℃). Therefore, it is impossible to open the furnace ventilation too early during the high-temperature stage; it can only remove limited heat from the furnace wall surface, failing to solve the problem of heat accumulation inside the furnace core. Summary of the Invention

[0005] To address the technical problems existing in the background art, this invention proposes a rapid cooling graphitization treatment system and method for negative electrode materials.

[0006] This invention proposes a rapid cooling graphitization system for negative electrode materials, comprising an external gas supply unit, a control unit, a temperature measuring unit, and an Atchison box furnace with a vent pipe arranged at the bottom of the furnace. The vent pipe has vent holes spaced along its axial direction, which connect to the interior of the Atchison box furnace. The external gas supply unit has a nitrogen source, which is connected to the vent pipe through a pipeline to input nitrogen into the Atchison box furnace. After the Atchison box furnace is powered off, when the temperature measuring unit detects that the furnace temperature has dropped to a first set temperature, the control unit activates the external gas supply unit to introduce nitrogen into the furnace for forced convection cooling of the furnace core. When the temperature measuring unit detects that the furnace temperature has dropped to a second set temperature, the control unit shuts off the gas supply unit.

[0007] Preferably, the nitrogen source is a nitrogen cylinder group, and the main valve of the nitrogen cylinder group is connected to the gas distribution main pipe after pressure reduction; the external gas supply unit also has several flow meters and pressure gauges, the inlet of the flow meter is connected to the gas distribution main pipe, the outlet of the flow meter is connected to the vent pipe through a pipeline to adjust the nitrogen flow rate in the vent pipe, and the pressure gauge is installed on the gas distribution main pipe to monitor the gas pressure.

[0008] Preferably, the flow meter is a float flow meter, and the height of the float of the float flow meter is used to indicate and adjust the flow rate so that the flow rate of each vent pipe is consistent.

[0009] Preferably, the temperature measuring unit includes an infrared thermometer and a temperature measuring rod. One end of the temperature measuring rod is embedded in the furnace core material layer of the Atchison box furnace, and the other end of the temperature measuring rod extends to the outside of the furnace wall of the Atchison box furnace. The infrared thermometer is fixed on the furnace wall of the Atchison box furnace and is arranged directly opposite to the center of the temperature measuring hole at the other end of the temperature measuring rod.

[0010] Preferably, multiple temperature measuring rods are provided and arranged at intervals along the length of the Atchison box furnace body.

[0011] This invention also provides a method for rapidly cooling graphitization of anode materials, comprising the following steps: S1. Load the artificial negative electrode material into the Atchison box furnace with a pre-embedded ventilation pipe at the bottom. S2. Power on the Atchison box furnace for heating; S3. After the graphitization power supply is completed, monitor the temperature inside the Atchison box furnace. When the temperature inside the furnace naturally drops to the first set temperature, nitrogen is introduced into the furnace core through the vent pipe. The nitrogen escapes from the vent hole on the vent pipe to force convection cooling of the furnace core. S4. Control the flow rate and pressure of nitrogen to ensure a continuous flow of nitrogen. S5. When the furnace temperature drops to the second set temperature, stop the nitrogen supply and discharge the material after natural cooling.

[0012] Preferably, the monitoring of the temperature inside the Atchison box furnace specifically involves: measuring the temperature at the temperature measuring rod embedded in the furnace core using an infrared thermometer at preset time intervals; recording the temperature values ​​at each time point and forming a cooling curve; and monitoring the temperature change trend based on the cooling curve.

[0013] Preferably, the control of nitrogen flow rate and pressure is specifically as follows: the initial nitrogen pressure is set to 0.3 MPa and the initial flow rate is 25-35 kg / h; during the nitrogen introduction process, the nitrogen flow rate is monitored and adjusted in real time or periodically to keep the flow rate in each vent pipe consistent; when the nitrogen source pressure is detected to be lower than 0.3 MPa, the system switches to the backup nitrogen source to maintain a continuous and stable nitrogen supply.

[0014] In this invention, nitrogen gas is directly introduced into the bottom area of ​​the furnace core, where heat accumulation is most severe, through a pre-installed vent pipe with vent holes at the bottom of the furnace. The forced convection heat transfer created by the nitrogen flow overcomes the problems of poor heat dissipation and difficulty in heat dissipation caused by the dense furnace core and heat storage in the surrounding insulation layer of traditional Atchison box furnaces. Furthermore, this invention uses chemically inert nitrogen gas as the cooling medium, which not only effectively prevents oxidation reactions of the negative electrode material and carbonaceous plates at high temperatures but also eliminates the risk of explosion upon contact with water at high temperatures. Precise adjustment of the nitrogen flow rate and pressure allows for stable control of the cooling rate, improving the controllability and safety of the cooling process. Attached Figure Description

[0015] Figure 1 This is a flowchart of the rapid cooling graphitization treatment method for negative electrode materials proposed in this invention. Detailed Implementation

[0016] This invention proposes a rapid cooling graphitization system for negative electrode materials, comprising an external gas supply unit, a control unit, a temperature measurement unit, and an Acheson box furnace with a vent pipe arranged at the bottom of the furnace. The vent pipe has vent holes spaced along its axial direction, connecting to the interior of the Acheson box furnace. The external gas supply unit includes a nitrogen source, several flow meters, and a pressure gauge. The nitrogen source is connected to the vent pipe via a pipeline. Specifically, a nitrogen cylinder group is used as the nitrogen source. The main valve of the nitrogen cylinder group is connected to a gas distribution main after pressure reduction. The inlet of the flow meter is connected to the gas distribution main, and the outlet of the flow meter is connected to the vent pipe via a pipeline to regulate the nitrogen flow rate in the vent pipe. A pressure gauge is installed on the gas distribution main to monitor the gas pressure. This configuration allows nitrogen to be introduced into the Acheson box furnace through the gas distribution main and the vent pipe after the furnace is powered off, enabling forced convection between the nitrogen and the furnace gas to achieve a cooling effect.

[0017] In this embodiment, the flow meter is a float flow meter. The height of the float in the float flow meter is used to indicate and adjust the flow rate so that the flow rate in each vent pipe remains consistent.

[0018] Furthermore, the temperature measuring unit includes several infrared thermometers and several temperature measuring rods. The temperature measuring rods are arranged at intervals along the length of the Atchison box furnace body. One end of the temperature measuring rod is embedded in the furnace core material layer of the Atchison box furnace, and the other end of the temperature measuring rod extends to the outside of the Atchison box furnace wall. The infrared thermometers are fixed on the Atchison box furnace wall and are arranged directly opposite the center of the temperature measuring hole on the other end of the temperature measuring rod.

[0019] When the infrared thermometer detects that the temperature of the measuring rod (i.e., the furnace temperature) has dropped to the first set temperature, which is the temperature at which nitrogen will not decompose, it sends a signal to the control unit. The control unit then opens the main valve of the nitrogen cylinder group to allow nitrogen to flow into the furnace for forced cooling of the furnace core. During this process, the airflow and pressure in each vent pipe are monitored in real time by a flow meter and a pressure gauge. When the pressure of the nitrogen cylinder group is detected to be lower than 0.3 MPa, the system switches to the backup nitrogen cylinder group to maintain a continuous and stable flow of nitrogen. When the infrared thermometer detects that the furnace temperature has dropped to the second set temperature, it sends a second temperature signal to the control unit. At this time, the control unit closes the main valve on the nitrogen cylinder group to stop the continued flow of nitrogen.

[0020] Specifically, the operation process of the above system is as follows: Figure 1 The method for graphitizing a negative electrode material with rapid cooling provided herein includes the following steps: S1. Furnace preparation: Load the artificial negative electrode material into the Atchison box furnace with a pre-embedded vent pipe at the bottom.

[0021] Before powering on the graphitization process, the Atchison box furnace is loaded. Cooling piping assemblies are pre-installed at the bottom of the furnace, specifically including vent pipes spaced along the length of the furnace body. These vent pipes are made of high-temperature resistant carbon materials (such as graphite tubes or carbon tubes) and have a diameter of 60-150 mm. The vent pipes have vent holes spaced axially, with a diameter of 6 mm and a spacing of 150-200 mm between adjacent vent holes. The vent holes are at a 45-degree angle to the horizontal plane to facilitate uniform gas diffusion into the furnace core.

[0022] The vent pipe extends horizontally through the furnace wall and into the furnace chamber, positioned above the bottom carbon black surface and between the joints of the two bottom plates to avoid direct load-bearing. At regular intervals (e.g., 1 meter) below the vent pipe, curved graphite blocks are installed, with the highest point of the vent pipe flush with or slightly below the highest point of the blocks. These blocks support the weight of the material above, preventing the vent pipe from rupturing under pressure. One end of the vent pipe extending outside the furnace wall (e.g., 200mm) is reserved for connecting to an external gas supply line, while the other end inside the furnace is sealed with a graphite plug. During furnace loading, the artificial negative electrode material is filled into the furnace, and the vent pipe is embedded in the bottom area of ​​the furnace core.

[0023] S2. Electrical heating: Electrical heating is applied to the Atchison box furnace.

[0024] According to the conventional graphitization process, the Acheson box furnace is powered on and heated to bring the material inside the furnace to the high temperature required for graphitization (up to about 2800℃), thus completing the graphitization process.

[0025] S3. Temperature monitoring and cooling: After the graphitization power supply is completed, the temperature inside the Atchison box furnace is monitored. When the temperature inside the furnace naturally cools down to the first set temperature, nitrogen gas is introduced into the furnace core through the vent pipe. The nitrogen gas escapes from the vent hole on the vent pipe to force cooling of the furnace core.

[0026] The temperature monitoring method in this step is as follows: multiple temperature measuring rods are pre-embedded inside the furnace. One end of the temperature measuring rod is embedded in the furnace core material layer to monitor the furnace temperature; the other end of the temperature measuring rod extends to the outside of the furnace wall, corresponding to the infrared thermometer. Multiple temperature measuring points are arranged at intervals along the length of the furnace body. After power is supplied, at preset time intervals (e.g., every 2 hours), the infrared thermometer is used to measure the temperature at the other end of each temperature measuring rod, and the temperature values ​​at each time point are recorded to form a cooling curve to monitor the temperature change trend.

[0027] When the furnace temperature naturally cools down to the first set temperature, which is the temperature at which nitrogen no longer decomposes (e.g., ≤2000℃), nitrogen is introduced. Introducing nitrogen within this temperature range ensures efficient cooling while avoiding potential side reactions between nitrogen and materials at high temperatures. It also ensures that carbonaceous components inside the furnace (vent pipes, panels, etc.) are not oxidized in the inert atmosphere. Nitrogen escapes from the external gas supply unit through the vent holes in the vent pipe and directly enters the bottom area of ​​the furnace core, providing forced convection cooling to the heavily heated interior.

[0028] S4. Flow and pressure control: Controls the flow and pressure of nitrogen to ensure a continuous flow of nitrogen.

[0029] During the nitrogen introduction process, gas parameters are precisely adjusted via an external gas supply unit. The specific control method is as follows: Open the main valve of the nitrogen cylinder group and connect it to the gas distribution main after pressure reduction. Set the initial nitrogen pressure to 0.3 MPa and the initial flow rate to 25–35 kg / h (adjustable according to furnace conditions).

[0030] A pressure gauge is installed on the main gas distribution pipe to monitor the gas pressure in real time. Each branch is equipped with a flow meter (preferably a float flow meter). By adjusting the valves, the float height of all flow meters is kept consistent to ensure uniform nitrogen flow in each vent pipe, thereby ensuring consistent cooling effect in all areas of the furnace core bottom.

[0031] During the nitrogen introduction process, the flow rate should be monitored and fine-tuned every hour to ensure that the flow rate remains stable within the set range. When the pressure of the nitrogen cylinder group is detected to be lower than 0.3 MPa, switch to the backup nitrogen cylinder group in a timely manner to ensure a continuous and stable nitrogen flow input and avoid uneven cooling or air introduction into the furnace due to gas interruption.

[0032] S5. Cooling Termination and Discharge: When the furnace temperature drops to the second set temperature, stop the nitrogen supply and discharge the material after natural cooling.

[0033] Nitrogen gas is continuously introduced for forced cooling, and the temperature at the temperature measuring rod is measured at preset time intervals (e.g., every 2 hours) to monitor the cooling curve. At the same time, the removal progress of the auxiliary materials on the upper layer of the nine-grid can be monitored to comprehensively judge the temperature distribution inside the furnace.

[0034] When the temperature at the temperature measuring rod drops to the second set temperature, which is the target temperature for exiting the furnace (e.g., 500℃), stop the nitrogen supply. The specific operation is as follows: close the main valve of the nitrogen cylinder group, remove the external flow meter frame, pull the rubber tube out from the end of the vent pipe, and immediately plug the pipe opening with a graphite plug to prevent external air from flowing back into the furnace under negative pressure or convection, which could cause oxidation of the carbon tubes or products that have not been completely cooled.

[0035] Afterward, natural cooling continues. When the temperature at a designated location inside the furnace drops to ≤300℃, it is determined that the furnace discharge standard has been met, and the high-temperature suction and discharge operation is carried out.

[0036] Through the above steps, the present invention utilizes the pre-installed ventilation pipe at the bottom of the furnace to introduce nitrogen gas at the appropriate time after graphitization, thereby achieving forced convection cooling of the deep heat accumulation in the furnace core. Under the premise of ensuring product quality and safety, the cooling cycle is significantly shortened and production efficiency is improved.

[0037] The above process will be further explained below with reference to specific embodiments: Example 1

[0038] The dimensions of the Acheson box furnace used in this embodiment are: length 18m, width 4.5m, and height 3.2m. A ventilation pipeline is pre-installed along the length of the furnace bottom, using alternating main and auxiliary pipes. Main pipe: 150mm diameter graphite tube, 1800mm long, with 40mm diameter vent holes drilled on the side wall of the tube, spaced 100mm apart, at a 45° angle to the horizontal plane. A total of 8 main pipes are installed.

[0039] Auxiliary pipes: 60mm diameter carbon tubes connected by 90mm diameter sleeves, with vent holes drilled on the sidewalls of the tubes. A total of 7 auxiliary pipes are installed.

[0040] The specific process is as follows: S1. Load artificial graphite anode material into the furnace, with a loading capacity of approximately 85 tons.

[0041] S2. The furnace is heated by electricity according to the conventional graphitization process, with the highest furnace temperature reaching 2820℃ and the holding time being 24 hours.

[0042] S3. After power supply is completed, use an infrared thermometer to monitor the temperature of the temperature measuring rod embedded in the furnace core. When the furnace temperature naturally drops to 1980℃, start the external gas supply unit.

[0043] S4. Control the initial nitrogen pressure to 0.3 MPa and the initial nitrogen flow rate to 28 kg / h (adjust the float height of each branch flowmeter to be consistent). During nitrogen supply, record the flow rate every hour and make minor adjustments to ensure the flow rate remains stable within the range of 27–29 kg / h. When the nitrogen cylinder group pressure drops below 0.3 MPa, automatically switch to the standby nitrogen cylinder group.

[0044] S5. When the furnace temperature naturally drops to 500℃, turn off the external gas supply unit, let the furnace continue to cool naturally for another 300℃, then discharge the material and record the cooling results.

[0045] In this embodiment, the temperature was reduced from 1980℃ to 500℃ in 52 hours, with an average cooling rate of approximately 28.5℃ / h during the nitrogen-forced cooling stage. After nitrogen supply was stopped, natural cooling continued. When the temperature at a designated location in the furnace core dropped to 300℃, the total cooling cycle (from the end of power supply to furnace exit) was 26 days. The product's specific surface area (BET) was 1.85 m² / g, which is essentially equivalent to that of the natural cooling process (1.82 m² / g), with no significant oxidation. The gas supply pipeline was inspected after exiting the furnace, and the pipeline structure was intact, with no cracks or blockages.

[0046] Example 2

[0047] In this embodiment, the same Atchison box furnace as in Embodiment 1 is used, but all the ventilation pipes are made of carbon tubes with a diameter of 60 mm, a total of 20 tubes are installed, and they are arranged at equal intervals along the length of the furnace body. Each carbon tube has a 25 mm diameter exhaust hole drilled on its side wall, spaced 80 mm apart.

[0048] The specific process is as follows: S1. The furnace is loaded with artificial graphite anode material, with a loading capacity of approximately 82 tons.

[0049] S2. The furnace is heated by electricity according to the conventional graphitization process, with the maximum furnace temperature reaching 2800℃ and the holding time being 24 hours.

[0050] S3. After power supply is completed, use an infrared thermometer to monitor the temperature of the temperature measuring rod embedded in the furnace core. When the furnace temperature naturally drops to 1950℃, start the external gas supply unit.

[0051] S4. Control the initial nitrogen pressure to 0.32 MPa and the initial nitrogen flow rate to 32 kg / h (adjust the float height of each branch flowmeter to be consistent). During nitrogen flow, record the flow rate every 2 hours and make minor adjustments to ensure balanced flow in each branch. Similar to Example 1, when the nitrogen cylinder group pressure drops below 0.3 MPa, automatically switch to the standby nitrogen cylinder group.

[0052] S5. When the furnace temperature naturally drops to 500℃, turn off the external gas supply unit, let the furnace continue to cool naturally for another 300℃, then discharge the material and record the cooling results.

[0053] In this embodiment, the temperature was reduced from 1950℃ to 500℃ in 48 hours, with an average cooling rate of approximately 30.2℃ / h; the total cooling cycle (from the end of power supply to the furnace exit) was 24 days; the product specific surface area (BET) test result was 1.88 m² / g. The ventilation pipeline was inspected after exiting the furnace and the pipeline structure was intact.

[0054] Example 3

[0055] This embodiment uses a larger-sized Atchison box furnace with dimensions of 24m in length, 5.2m in width, and 3.5m in height. The ventilation system employs alternating main pipes (150mm diameter graphite tubes) and auxiliary pipes (60mm diameter carbon tubes), with 12 main pipes and 11 auxiliary pipes. The exhaust ports have diameters of 40mm (main pipes) and 25mm (auxiliary pipes), spaced 120mm apart.

[0056] The specific process is as follows: S1. Load artificial graphite anode material into the furnace, with a loading capacity of approximately 120 tons.

[0057] S2. The furnace is heated by electricity according to the conventional graphitization process, with the highest furnace temperature reaching 2850℃ and the holding time being 28 hours.

[0058] S3. After power supply is completed, use an infrared thermometer to monitor the temperature of the temperature measuring rod embedded in the furnace core. When the furnace temperature naturally drops to 2000℃, start the external gas supply unit.

[0059] S4. Control the initial nitrogen pressure to 0.35 MPa and the initial nitrogen flow rate to 35 kg / h (adjust the float height of each branch flowmeter to be consistent). During nitrogen flow, record the flow rate every hour and make minor adjustments to ensure balanced flow in each branch. Similar to Example 1, when the nitrogen cylinder group pressure drops below 0.3 MPa, automatically switch to the standby nitrogen cylinder group.

[0060] S5. When the furnace temperature naturally drops to 500℃, turn off the external gas supply unit, let the furnace continue to cool naturally for another 300℃, then discharge the material and record the cooling results.

[0061] In this embodiment, the temperature was reduced from 2000℃ to 500℃ in 62 hours, with an average cooling rate of approximately 24.2℃ / h; the total cooling cycle (from the end of power supply to the furnace exit) was 29 days; the product specific surface area (BET) test result was 1.92 m² / g. The ventilation pipeline was inspected and found to be intact and without abnormalities.

[0062] Comparative Example

[0063] (1) Furnace body and piping configuration The same Acheson box furnace (18m long, 4.5m wide, and 3.2m high) as in Example 1 was used. No ventilation pipes were pre-installed, and no external auxiliary cooling methods were used. Natural cooling was used entirely.

[0064] (2) Furnace loading and graphitization The furnace is loaded with artificial graphite anode material, with a loading capacity of approximately 85 tons. The maximum furnace temperature reaches 2810℃, and the holding time is 24 hours.

[0065] (3) Cooling process After the power supply is completed, the furnace body is shut down, and no external intervention is carried out, relying entirely on natural convection and conduction for heat dissipation.

[0066] In this comparative example, the total cooling cycle from the end of power supply to the furnace core temperature dropping to 300℃ was 42 days; the average cooling rate was approximately 2.5℃ / h, from 2810℃ to 300℃, with a total temperature difference of 2510℃; the product specific surface area (BET) test result was 1.83 m² / g.

[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rapid cooling graphitization treatment system for negative electrode materials, characterized in that, The furnace includes an external gas supply unit, a control unit, a temperature measuring unit, and an Atchison box furnace with a vent pipe at the bottom. The vent pipe has vent holes spaced along its axial direction, which connect to the furnace interior. The external gas supply unit has a nitrogen source, which is connected to the vent pipe through a pipeline to supply nitrogen into the Atchison box furnace. When the Atchison box furnace is powered off, the control unit activates the external gas supply unit to introduce nitrogen into the furnace to force convection cooling of the furnace core when the temperature measuring unit detects that the furnace temperature has dropped to the first set temperature. When the temperature measuring unit detects that the furnace temperature has dropped to the second set temperature, the control unit shuts off the gas supply unit.

2. The rapid cooling graphitization treatment system for negative electrode materials according to claim 1, characterized in that, The nitrogen source is specifically a nitrogen cylinder group. The main valve of the nitrogen cylinder group is connected to the gas distribution main pipe after pressure reduction. The external gas supply unit also has several flow meters and pressure gauges. The inlet of the flow meter is connected to the gas distribution main pipe, and the outlet of the flow meter is connected to the vent pipe through a pipeline to adjust the nitrogen flow rate in the vent pipe. The pressure gauge is installed on the gas distribution main pipe to monitor the gas pressure.

3. The rapid cooling graphitization treatment system for negative electrode materials according to claim 2, characterized in that, The flow meter is a float flow meter, and the height of the float in the float flow meter is used to indicate and adjust the flow rate so that the flow rate in each vent is consistent.

4. The rapid cooling graphitization treatment system for negative electrode materials according to claim 1, characterized in that, The temperature measuring unit includes an infrared thermometer and a temperature measuring rod. One end of the temperature measuring rod is embedded in the furnace core material layer of the Atchison box furnace, and the other end of the temperature measuring rod extends to the outside of the furnace wall of the Atchison box furnace. The infrared thermometer is fixed on the furnace wall of the Atchison box furnace and is arranged directly opposite the center of the temperature measuring hole at the other end of the temperature measuring rod.

5. The rapid cooling graphitization treatment system for negative electrode materials according to claim 4, characterized in that, Multiple temperature measuring rods are provided and arranged at intervals along the length of the Atchison box furnace body.

6. A method for rapidly cooling graphitization of a negative electrode material, characterized in that, The application of the rapid cooling graphitization system for negative electrode materials as described in any one of claims 1-4 includes the following steps: S1. Load the artificial negative electrode material into the Atchison box furnace with a pre-embedded ventilation pipe at the bottom. S2. Power on the Atchison box furnace for heating; S3. After the graphitization power supply is completed, monitor the temperature inside the Atchison box furnace. When the temperature inside the furnace naturally drops to the first set temperature, nitrogen is introduced into the furnace core through the vent pipe. The nitrogen escapes from the vent hole on the vent pipe to force convection cooling of the furnace core. S4. Control the flow rate and pressure of nitrogen to ensure a continuous flow of nitrogen. S5. When the furnace temperature drops to the second set temperature, stop the nitrogen supply and discharge the material after natural cooling.

7. The method for rapid cooling graphitization of negative electrode materials according to claim 6, characterized in that, The specific method for monitoring the temperature inside the Atchison box furnace is as follows: at preset time intervals, an infrared thermometer is used to measure the temperature at the temperature measuring rod embedded in the furnace core; the temperature values ​​at each time point are recorded and a cooling curve is generated; and the temperature change trend is monitored based on the cooling curve.

8. The method for rapid cooling graphitization of negative electrode materials according to claim 6, characterized in that, The control of nitrogen flow rate and pressure is specifically as follows: the initial nitrogen pressure is set to 0.3 MPa and the initial flow rate is 25-35 kg / h; during the nitrogen introduction process, the nitrogen flow rate is monitored and adjusted in real time or periodically to keep the flow rate in each venting pipe consistent; when the nitrogen source pressure is detected to be lower than 0.3 MPa, the system switches to the backup nitrogen source to maintain a continuous and stable nitrogen supply.

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