Fluidized bed reaction system of silicon-carbon negative electrode material

Abstract

The application relates to a fluidized bed reaction system of a silicon-carbon negative electrode material. The fluidized bed reaction system of the silicon-carbon negative electrode material comprises a drying tank, a fluidized bed reactor and a discharge tank; the drying tank has a material cavity, the drying tank can dry material in the material cavity, and can also deliver replacement gas to the material cavity to replace gas in the material cavity; the fluidized bed reactor has a gas-solid separation zone, a reaction zone and a starting fluidization zone arranged in sequence from top to bottom inside the fluidized bed reactor, the reaction zone is communicated with the material cavity to receive the dried material; the discharge tank has a dust removal cavity, the dust removal cavity is communicated with the gas-solid separation zone through a discharge pipeline, the discharge pipeline is provided with a burst assembly, when the pressure in the fluidized bed reactor exceeds a first preset value, the burst assembly can be broken to release the gas in the fluidized bed reactor, and at the same time, the powder in the fluidized bed reactor can be discharged to the washing liquid in the dust removal cavity through the discharge pipeline.

Description

Technical Field

[0001] This application relates to the field of silicon-carbon anode material preparation technology, and in particular to a fluidized bed reaction system for silicon-carbon anode materials. Background Technology

[0002] Fluidized bed reactors for silicon-carbon anode materials use porous carbon as raw material. During the reaction, the material is fully fluidized within the reactor, while silane gas undergoes decomposition at high temperatures. The resulting amorphous silicon is deposited within the pores of the porous carbon, ultimately forming a silicon-carbon composite anode material. These fluidized bed reactors typically employ a slender, vertical cylindrical structure. Gas is introduced from the bottom to fluidize the material, and sidewall heating is used to achieve the decomposition and deposition of silane gas.

[0003] However, abnormal reactions may occur during this process, often accompanied by a sharp rise in temperature and pressure within the reactor. Such operating conditions can easily cause the reactor to exceed its design specifications, leading to equipment damage, and in severe cases, even rupture, resulting in a safety accident. Summary of the Invention

[0004] Therefore, it is necessary to provide a fluidized bed reaction system for silicon-carbon anode materials to address the aforementioned technical problems.

[0005] A fluidized bed reaction system for silicon-carbon anode materials includes:

[0006] A drying tank having a material chamber, the drying tank being able to dry the material in the material chamber and also being able to deliver a displacement gas into the material chamber to replace the gas in the material chamber;

[0007] A fluidized bed reactor, internally comprising, from top to bottom, a gas-solid separation zone, a reaction zone, and an initial fluidization zone, wherein the reaction zone is connected to the material chamber to receive the dried material; and

[0008] The discharge tank has a dust removal chamber, which is connected to the gas-solid separation zone through a discharge pipe. The discharge pipe is equipped with a bursting component. When the pressure inside the fluidized bed reactor exceeds a first preset value, the bursting component can rupture to release the gas inside the fluidized bed reactor. At the same time, the powder inside the fluidized bed reactor can be discharged into the washing liquid in the dust removal chamber through the discharge pipe.

[0009] In one embodiment, the bottom of the drying tank has a discharge port communicating with the reaction zone;

[0010] The discharge port is provided with a first material valve and a second material valve in sequence along the discharge direction, and the second material valve is a star-shaped discharge valve.

[0011] In one embodiment, the drying tank is further provided with an exhaust port communicating with the material chamber;

[0012] The fluidized bed reaction system for silicon-carbon anode material further includes a control component and a first detector. The first detector, the first material valve, and the second material valve are all electrically connected to the control component. The first detector can detect the oxygen content at the exhaust port. The control component can open the first material valve and the second material valve when the oxygen content at the exhaust port is lower than a second preset value, so as to discharge the dried material from the discharge port.

[0013] In one embodiment, the silicon-carbon anode material fluidized bed reaction system further includes at least one of the following features:

[0014] The drying tank is equipped with a first stirring mechanism, which is capable of stirring the material in the material chamber.

[0015] The drying tank is equipped with a second detector, which can detect the weight of the material in the material chamber;

[0016] The end of the discharge pipe that extends into the dustproof chamber is equipped with a horn nozzle;

[0017] The top of the discharge tank is equipped with a baffle plate, and the end of the discharge pipe is sealed through the baffle plate;

[0018] The top of the discharge tank is provided with a water inlet that communicates with the dust removal chamber.

[0019] In one embodiment, the fluidized bed reactor is provided with a first filter assembly at the top of the gas-solid separation zone, the first filter assembly being capable of filtering fluidized particles in the gas.

[0020] In one embodiment, the silicon-carbon anode material fluidized bed reaction system further includes a third detector, a control component, and a backflushing component;

[0021] The third detector is electrically connected to the control component and is capable of detecting the pressure difference between the inlet and outlet of the first filter component;

[0022] The backflush assembly is located in the fluidized bed reactor and is electrically connected to the control assembly;

[0023] The control component can control the backflushing component to backflush the first filter component when the pressure difference between the inlet and outlet of the first filter component is higher than a third preset value, so as to cause the fluidized particles to detach from the first filter component.

[0024] In one embodiment, the fluidized bed reactor is provided with a first inlet pipe and a second inlet pipe. The first inlet pipe is connected to the reaction zone to deliver process gas to the reaction zone, and the second inlet pipe is connected to the initial fluidization zone to deliver fluidizing gas to the initial fluidization zone. The first inlet pipe is located away from the second inlet pipe.

[0025] In one embodiment, the silicon-carbon anode material fluidized bed reaction system further includes at least one of the following features:

[0026] The fluidized bed reactor is equipped with an annular distributor that extends into the reaction zone and is connected to the outlet of the first air inlet pipe. The annular distributor has multiple first air holes.

[0027] The fluidized bed reactor is provided with a fluidization distribution plate at the junction of the reaction zone and the initial fluidization zone. The fluidization distribution plate has a plurality of second air holes, and the end of the second air inlet pipe extends into the initial fluidization zone and is arranged downward.

[0028] The fluidized bed reactor is also provided with a third air inlet pipe, which is connected to the initial fluidization zone to deliver a driving gas, wherein the pressure of the driving gas is greater than the pressure of the fluidizing gas.

[0029] In one embodiment, the fluidized bed reaction system further includes a cooling tank connected to the reaction zone, the cooling tank being able to receive and cool the reacted material.

[0030] In one embodiment, the silicon-carbon anode material fluidized bed reaction system further includes at least one of the following features:

[0031] The outer periphery of the cooling tank is provided with a cooling water jacket, and the cooling water jacket is connected to an inlet pipe and a drain pipe.

[0032] The cooling tank is equipped with a second stirring mechanism, which is capable of stirring the material in the cooling tank;

[0033] The cooling tank is equipped with a discharge valve at its discharge port. The fluidized bed reaction system also includes a fourth detector and a control component. The fourth detector is electrically connected to the control component and can detect the temperature information of the cooling tank. The control component is electrically connected to the discharge valve and can open the discharge valve when the temperature of the cooling tank is lower than a fourth preset value.

[0034] This application addresses two issues. First, it installs a discharge tank downstream of the fluidized bed reactor and a bursting assembly on the discharge pipe connecting the fluidized bed reactor and the discharge tank. The bursting assembly can relieve pressure in the fluidized bed reactor, ensuring that the pressure remains within a safe value (i.e., a first preset value). This prevents damage to the fluidized bed reactor due to excessive pressure. Furthermore, the dust removal function of the discharge tank prevents the powder from being released into the atmosphere, further preventing safety accidents. Second, it also addresses the issue at its source by installing a drying tank upstream of the fluidized bed reactor. This prevents excessive pressure caused by moisture-laden particle agglomeration and channeling, thus preventing damage to the fluidized bed reactor and avoiding safety accidents. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a fluidized bed reaction system for silicon-carbon anode materials provided in an embodiment of this application.

[0036] Figure 2 This is a schematic diagram of the structure of the annular distributor of a fluidized bed reaction system for silicon-carbon anode materials provided in an embodiment of this application.

[0037] The labels in the attached diagram are explained as follows:

[0038] 1. Fluidized bed reaction system for silicon-carbon anode materials; 100. Drying tank; 110. First material valve; 120. Second material valve; 130. First stirring mechanism; 131. First motor; 132. First stirring blade; 140. Feed inlet; 150. First electric heating mechanism; 160. Sending chamber; 200. Fluidized bed reactor; 200a. Gas-solid separation zone; 200b. Reaction zone; 200c. Initial fluidization zone; 210. Explosion assembly; 220. Backflush assembly; 221. Nitrogen storage tank; 222. Pulse valve; 231. First air inlet pipe; 2311. Flame arrester; 2312. Check valve; 23 2. Second air inlet pipe; 233. Third air inlet pipe; 240. Annular distributor; 241. Outer shell; 242. Annular pipe; 243. Support air inlet pipe; 250. Fluidized distribution plate; 260. Second electric heating mechanism; 270. Discharge valve; 271. Fourth detector; 272. Fifth detector; 300. Discharge tank; 310. Horn nozzle; 320. Water baffle; 300a. Water inlet; 330. Drain valve; 400. Cooling tank; 410. Cooling water jacket; 420. Water inlet pipe; 430. Drain pipe; 440. Second stirring mechanism; 450. Discharge valve; 460. Sixth detector. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0040] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" 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. Similarly, "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.

[0044] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0045] See Figure 1 , Figure 1 This illustration shows a schematic diagram of a silicon-carbon anode material fluidized bed reaction system 1 according to an embodiment of this application. The silicon-carbon anode material fluidized bed reaction system 1 provided in this embodiment includes a drying tank 100, a fluidized bed reactor 200, and a discharge tank 300. The drying tank 100 has a material chamber, which can dry the material in the material chamber and also supply a displacement gas to the material chamber to replace the gas in the material chamber. The fluidized bed reactor 200 has a gas-solid separation zone 200a and a reaction zone arranged sequentially from top to bottom. Zone 200b and initial fluidization zone 200c are connected to the material chamber to receive the dried material. The discharge tank 300 has a dust removal chamber, which is connected to the gas-solid separation zone 200a through a discharge pipe. The discharge pipe is equipped with a bursting component 210. When the pressure inside the fluidized bed reactor 200 exceeds a first preset value, the bursting component 210 can rupture to release the gas inside the fluidized bed reactor 200. At the same time, the powder inside the fluidized bed reactor 200 can be discharged into the washing liquid in the dust removal chamber through the discharge pipe.

[0046] To prevent safety accidents caused by abnormal reactions in the fluidized bed reactor 200, this application installs a rupture component 210 on the discharge pipe connecting the fluidized bed reactor 200 and the discharge tank 300. Once the internal pressure of the fluidized bed reactor 200 exceeds a first preset value due to an abnormal reaction, the rupture component 210 will rupture, quickly releasing the gas inside the fluidized bed reactor 200 and reducing the pressure of the fluidized bed reactor 200 to within the first preset value, thus preventing equipment damage. At the same time, the powder inside the fluidized bed reactor 200 is also discharged into the washing liquid in the dust removal chamber through the discharge pipe, preventing direct discharge into the atmosphere and avoiding particulate matter explosion, which can further prevent the occurrence of safety accidents.

[0047] Furthermore, the applicant discovered that during the production of silicon-carbon anode materials, if channeling occurs within the fluidized bed reactor 200, it can easily lead to localized areas being within the explosion limits, posing a safety hazard. Moist materials are one of the main causes of channeling in the fluidized bed reactor 200. To address this, this application adds a drying tank 100 upstream of the fluidized bed reactor 200. The drying tank 100 can dry the material before it enters the fluidized bed reactor 200, removing moisture and preventing selective airflow and channeling caused by material agglomeration and uneven bed resistance. Moreover, the drying tank 100 of this application also displaces gas in the material chamber, facilitating the removal of moisture and preventing air from entering the fluidized bed and causing danger.

[0048] As can be seen, this application addresses two main issues. First, by installing a discharge tank 300 downstream of the fluidized bed reactor 200 and a bursting assembly 210 on the discharge pipe connecting the fluidized bed reactor 200 and the discharge tank 300, the bursting assembly 210 can depressurize the fluidized bed reactor 200, ensuring that the pressure of the fluidized bed reactor 200 remains within a safe value (i.e., the first preset value). This prevents damage to the fluidized bed reactor 200 due to excessive pressure. Furthermore, the dust removal function of the discharge tank 300 prevents the powder inside the fluidized bed reactor 200 from being discharged into the atmosphere, further preventing safety accidents. Second, by addressing the issue at its source by installing a drying tank 100 upstream of the fluidized bed reactor 200, the application prevents excessive pressure caused by channeling in the fluidized bed reactor 200, thus preventing damage to the fluidized bed reactor 200 and avoiding safety accidents.

[0049] The drying tank 100 serves as the main body for drying materials. After the materials are dried, they can be conveyed to the reaction zone 200b of the fluidized bed reactor 200. Its designed operating temperature (withstand temperature) can reach 150℃~300℃, and its designed operating pressure (withstand pressure) can reach 0.1MPaG~0.5MPaG. In some embodiments of this application, the bottom of the drying tank 100 has a discharge port communicating with the reaction zone 200b; wherein, a first material valve 110 and a second material valve 120 are sequentially provided at the discharge port along the discharge direction, and the second material valve 120 is a star-shaped discharge valve. After the materials are dried, the first material valve 110 and the second material valve 120 are opened, and the dried materials are conveyed to the reaction zone 200b of the fluidized bed reactor 200 through the discharge port. This application sets up a series of dual valve systems at the discharge port. The rotary valve, serving as the second valve, is the core sealing and feeding device. The sealing cavity formed between its blades and the shell can effectively seal the material, cutting off the upstream and downstream airflow. This ensures stable internal pressure and prevents air leakage or ingress while continuously and uniformly discharging the material. The rotary valve needs to control a certain feeding rate to avoid the phenomenon of material difficulty in fluidization caused by too much material entering the fluidized bed reactor at the same time. The first material valve 110 connected in series upstream mainly plays an auxiliary and protective role. For example, when the rotary valve needs maintenance or becomes blocked, closing the first material valve 110 can completely isolate it from the upstream pressure system, enabling maintenance without shutting down the system. In situations requiring absolute sealing (such as system pressure maintenance or long-term shutdown), the closure of the dual valves provides additional sealing protection.

[0050] Optionally, see Figure 1 The material chamber is a cone-shaped cavity that is larger at the top and smaller at the bottom. This design facilitates the discharge of material through the discharge port.

[0051] Optionally, such as Figure 1 As shown, the silicon-carbon anode material fluidized bed reaction system 1 also includes a sending chamber 160, which can be a three-way structure, with one port connected to a gas source, one port connected to a second material valve 120, and the other port connected to the reaction zone 200b of the fluidized bed reactor 200. The dried material can flow into the reaction zone 200b of the fluidized bed reactor 200 under the carry of the gas.

[0052] In some embodiments of this application, the drying tank 100 is further provided with an exhaust port (not shown in the figures) communicating with the material chamber; the silicon-carbon anode material fluidized bed reaction system 1 also includes a control component (not shown in the figures) and a first detector (not shown in the figures). The first detector, the first material valve 110, and the second material valve 120 are all electrically connected to the control component. The first detector can detect the oxygen content at the exhaust port. The control component can also open the first material valve 110 and the second material valve 120 when the oxygen content at the exhaust port is lower than a second preset value, so as to discharge the dried material from the discharge port. The control component can determine whether the material has been dried by the oxygen content at the exhaust port, thereby controlling the opening and closing of the first material valve 110 and the second material valve 120, which can improve the automation level of the entire system.

[0053] The drying tank 100 should be equipped with a nitrogen inlet (not shown in the attached figure) that communicates with the material chamber. The nitrogen inlet is used to deliver replacement gas into the material chamber. After the porous carbon is added, the air is discharged from the exhaust port through multiple replacements.

[0054] Optionally, the first detector is an online oxygen analyzer.

[0055] Optionally, an exhaust valve is provided at the exhaust port, and the exhaust valve is electrically connected to the control component. The control component can also close the exhaust valve when the oxygen content at the exhaust port is lower than a first preset value. After the material is dried, external air can be prevented from entering the material chamber of the drying tank 100 through the exhaust port, thus preventing air from entering the reactor and causing danger.

[0056] See also Figure 1 The top of the drying tank 100 may be provided with a feed inlet 140 that communicates with the material chamber. The feed inlet 140 may be connected to an external material silo. The feed inlet 140 is equipped with a feed valve.

[0057] In some embodiments of this application, such as Figure 1 As shown, the outer wall of the drying tank 100 is provided with a first electric heating mechanism 150, which can heat the material chamber. Of course, a jacket can also be provided on the outer wall of the drying tank 100, and the material chamber can be heated by circulating a heat medium in the jacket.

[0058] In some embodiments of this application, such as Figure 1 As shown, the drying tank 100 is equipped with a first stirring mechanism 130, which can stir the material in the material chamber. The first stirring mechanism 130 can be used to stir the material in the material chamber, which is conducive to the evaporation of water vapor on the material and can accelerate the drying process of the material.

[0059] Optionally, the first stirring mechanism 130 includes a first motor 131 and a first stirring blade 132. The first motor 131 is located at the top of the drying tank 100, and the first stirring blade 132 is located in the material chamber and connected to the output shaft of the first motor 131.

[0060] In some embodiments of this application, the drying tank 100 is equipped with a second detector, which can detect the weight of the material in the material chamber. When the dried material is transported to the reaction zone 200b of the fluidized bed reactor 200, the second detector can detect the weight change of the material in the drying tank 100 in real time, which can be compared with the weight by manual weighing. This can prevent material residue from occurring during the transportation of the material to the fluidized bed reactor 200 and ensure the stability of the batch feeding process.

[0061] Optionally, the second detector can be a load cell. The second detector can be installed according to the type of drying tank 100. For example, if the drying tank 100 is a vertical tank, the second detector can replace the original support legs of the drying tank 100, and the weight of the material inside the drying tank 100 can be indirectly calculated by measuring the weight change of the entire drying tank 100. As another example, if the drying tank 100 is a trunnion-type suspended tank, a pressure-type or tension-type load cell can be used to measure the weight change of the entire drying tank 100 to indirectly calculate the weight of the material inside the drying tank 100.

[0062] The discharge tank 300 is mainly used for dust removal during the pressure relief process. Multiple rupture components 210 can be connected in parallel on its connecting pipeline to the fluidized bed reactor 200 to achieve rapid pressure relief. The number of rupture components 210 can be set according to requirements, such as 2, 3, 4, or more. Each rupture component 210 can be a rupture disc, with a release pressure between 0.05 MPaG and 0.4 MPaG.

[0063] In some embodiments of this application, such as Figure 1 As shown, a horn nozzle 310 is provided at the end of the discharge pipe that extends into the dustproof chamber. The horn nozzle 310 enables the powder to come into uniform contact with the water for washing, thereby enhancing the dust removal effect. The horn nozzle 310 can be located 100mm to 1000mm below the liquid level in the washing chamber.

[0064] Among them, see Figure 1 The top of the discharge tank 300 may be equipped with a baffle plate 320, and the end of the discharge pipe is sealed by the baffle plate 320. The baffle plate 320 can prevent water droplets generated by splashing during the exhaust process from being discharged with the gas.

[0065] See also Figure 1 The top of the discharge tank 300 can be connected to a water inlet 300a. Fresh water can be added to the dust removal chamber of the discharge tank 300 through the water inlet 300a.

[0066] See also Figure 1 The bottom of the discharge tank 300 may be provided with a drain port that communicates with the dust removal chamber, and the drain port is equipped with a drain valve 330. Wastewater in the discharge tank 300 can be discharged by opening the drain valve 330.

[0067] The fluidized bed reactor 200 serves as the main body of the reaction, and its designed operating pressure (i.e., pressure resistance) can reach 0.3 MPaG~1.5 MPaG, and its designed operating temperature can reach 1000℃~1500℃. The reactor is equipped with vents in the gas-solid separation zone 200a, each vent connected to a rupture disc. The number of vents can be set from 1 to 5 depending on the material loading.

[0068] In some embodiments of this application, the fluidized bed reactor 200 is provided with a first filter assembly at the top of the gas-solid separation zone 200a. The first filter assembly is capable of filtering fluidized particles in the gas. The first filter assembly can prevent fluidized particles from being discharged from the vent with the gas.

[0069] Optionally, the first filter element may be a sintered metal filter element with a temperature resistance of up to 800℃~1000℃.

[0070] Optionally, such as Figure 1 As shown, at least the side of the gas-solid separation zone 200a closest to the reaction zone 200b is a variable-diameter region, wider at the top and narrower at the bottom. This design reduces the terminal velocity of the fluidized particles, minimizing carry-over, which extends the service life of the first filter element.

[0071] Furthermore, in some embodiments of this application, the silicon-carbon anode material fluidized bed reaction system 1 further includes a third detector and a backflushing assembly 220; the third detector is electrically connected to the control assembly and is capable of detecting the pressure difference between the inlet and outlet of the first filter assembly; the backflushing assembly 220 is disposed in the fluidized bed reactor and is electrically connected to the control assembly; the control assembly is used to control the backflushing assembly 220 to backflush the first filter assembly when the pressure difference between the inlet and outlet of the first filter assembly is higher than a third preset value, so as to cause the fluidized particles to detach from the first filter assembly. The normal operation of the first filter assembly can be ensured by the cooperation of the third detector and the backflushing assembly 220.

[0072] In one embodiment, the third detector may be a differential pressure sensor with two pressure ports, connected to the inlet and outlet of the filter element via a capillary tube or directly. This third detector directly measures the pressure difference, offering stronger anti-interference capabilities and often higher accuracy. Alternatively, the third detector may include two pressure sensors: one located at the inlet of the first filter element and capable of measuring its inlet pressure, and the other located at the outlet of the first filter element and capable of measuring its outlet pressure. The control component can then calculate the pressure difference between the inlet and outlet of the first filter element based on these pressures.

[0073] In one embodiment, the backflush assembly 220 can be a nitrogen pulse backflush valve assembly, such as... Figure 1 As shown, the system may include a nitrogen storage tank 221, an electromagnetic pilot valve, a pulse valve 222, a blowpipe, and a venturi tube. The outlet of the nitrogen storage tank 221 is connected in series with the electromagnetic pilot valve and the pulse valve 222. The blowpipe extends above the first filter assembly and communicates with the pulse valve 222. The venturi tube is located on the nozzle of the blowpipe. The electromagnetic pilot valve is electrically connected to a control component. Based on a preset interval or the pressure difference of the first filter assembly, the control component issues a dust removal command, energizing and opening the electromagnetic pilot valve, releasing the gas pressure in the upper chamber of the diaphragm of the pulse valve 222. The sudden drop in pressure in the upper chamber of the diaphragm of the pulse valve 222 causes the diaphragm to be violently pushed upwards by the compressed nitrogen gas below, instantly opening the main gas path. A large amount of high-pressure nitrogen gas rushes from the storage tank into the blowpipe. The high-speed nitrogen gas flows through the blowpipe, exits from the nozzle, and after being induced and amplified by the venturi tube, rushes into the interior of the first filter assembly at high speed, causing it to expand and vibrate rapidly, thereby shaking off the surface dust layer.

[0074] In some embodiments of this application, such as Figure 1 As shown, the reaction zone 200b is divided into multiple sub-reaction zones from top to bottom, and the fluidized bed reactor 200 is equipped with a second electric heating mechanism 260 in each sub-reaction zone. The second electric heating mechanisms 260 can be arranged sequentially from top to bottom, and can independently control the temperature of different sub-reaction zones.

[0075] Optionally, the number of sub-reaction zones can be set to three, that is, the fluidized bed reactor 200 is divided into one sub-reaction zone each in the upper, middle and lower parts of the reaction zone 200b.

[0076] Among them, such as Figure 1As shown, the fluidized bed reactor 200 is also equipped with a fifth detector 271 and a sixth detector 272 in each sub-reaction zone. The fifth detector 271 can detect the temperature information of the corresponding sub-reaction zone, and the sixth detector 272 can detect the pressure information of the corresponding sub-reaction zone. The control component is electrically connected to the fifth detector 271 and can adjust the power value of the corresponding second electric heating mechanism 260 based on the temperature of each sub-reaction zone. The control component is also electrically connected to the fifth detector 271 and can determine whether the fluidization state of each sub-reaction zone is normal based on the difference in pressure of different sub-reaction zones, thereby determining whether the reaction process is normal.

[0077] The height difference between the fifth detector 271 and the sixth detector 272 in each sub-reaction zone is 500mm~2000mm. It should be noted that... Figure 1 The image only shows the upper sub-reaction zone equipped with a fifth detector 271 and a sixth detector 272. The fifth detector 271 can be a temperature sensor, and the sixth detector 272 can be a pressure sensor.

[0078] In some embodiments of this application, such as Figure 1 As shown, the fluidized bed reactor 200 is provided with a first inlet pipe 231 and a second inlet pipe 232. The first inlet pipe 231 is connected to the reaction zone 200b to supply process gas (e.g., silane gas) to the reaction zone 200b, and the second inlet pipe 232 is connected to the initial fluidization zone 200c to supply fluidizing gas (e.g., low-pressure inert gas) to the initial fluidization zone 200c. The first inlet pipe 231 is located away from the second inlet pipe 232. This application uses two inlet pipes to independently supply process gas and fluidizing gas, avoiding the reaction byproduct problem caused by the low-temperature effect in the fluidization zone due to the low-temperature fluidizing gas, allowing the process gas to quickly enter the high-temperature zone and improve reaction selectivity. Furthermore, this application sets the first inlet pipe 231 away from the second inlet pipe 232, so that the first inlet pipe 231 does not need to be located in the lower sub-reaction zone, but can be located in the middle sub-reaction zone. This middle sub-reaction zone is less prone to channeling in the middle of the fluidized bed, preventing reaction safety problems caused by poor fluidization.

[0079] like Figure 1 As shown, the first air intake pipe 231 may be equipped with a flame arrester 2311 and a check valve 2312 in sequence along the air intake direction. This arrangement can prevent the explosion flame from backflowing into the pipe during an abnormal reaction process and causing secondary hazards.

[0080] In one embodiment, such as Figure 1As shown, the fluidized bed reactor 200 is equipped with an annular distributor 240, which extends into the reaction zone 200b and is connected to the outlet of the first inlet pipe 231. The annular distributor 240 has multiple first gas holes. The annular distributor 240 makes the process gas outlet more uniform, which is beneficial to the reaction.

[0081] Optionally, such as Figure 2 As shown, the annular distributor 240 may include a housing 241, an annular tube 242 and a plurality of supporting air inlet pipes 243; the annular tube 242 is located in the reaction zone 200b and has a plurality of first air holes; the housing 241 is fixed to the circumferential wall of the fluidized bed reactor 200; the plurality of supporting air inlet pipes 243 are circumferentially spaced and connected to the housing 241 and sealed to extend into the reaction zone and communicate with the annular tube 242.

[0082] The outer casing 241 can be connected to the fluidized bed reactor 200 via a flange. This application does not limit the installation method of the outer casing 241.

[0083] The diameter of the annular tube 242 should be as small as possible, and a first vent hole should be drilled on the upper side of the annular tube 242 to achieve the effect of gas distribution throughout the cavity. The diameter of the first vent hole on the annular tube 242 can be 1mm to 10mm.

[0084] The outer surfaces of the supporting intake pipe 243 and the annular pipe 242 are mirror-polished during the processing to reduce the accumulation of agglomerated powder on them.

[0085] In one embodiment, such as Figure 1 As shown, the fluidized bed reactor 200 has a fluidization distribution plate 250 at the junction of the reaction zone 200b and the initial fluidization zone 200c. The fluidization distribution plate 250 has multiple second air holes, and the end of the second air inlet pipe 232 extends into the initial fluidization zone 200c and is positioned downwards. This arrangement makes the distribution of fluidizing gas more uniform. The pore size of the second air holes is 1mm to 10mm.

[0086] In one embodiment, such as Figure 1 As shown, the fluidized bed reactor 200 is also equipped with a third inlet pipe 233, which is connected to the initial fluidization zone 200c and can transport a driving gas (e.g., high-pressure inert gas), wherein the pressure of the driving gas is greater than the pressure of the fluidizing gas. During the reaction, the driving gas (e.g., high-pressure inert gas) is injected at a certain frequency to increase the instantaneous fluidizing gas volume and the gas velocity through the orifices of the fluidization distribution plate 250, thereby disturbing the bed.

[0087] Optionally, the interval between jets of the power gas is 1 min to 10 min, and the duration of each jet is 1 s to 10 s.

[0088] In some embodiments of this application, such as Figure 1 As shown, the silicon-carbon anode material fluidized bed reaction system 1 also includes a cooling tank 400 connected to the reaction zone 200b. The cooling tank 400 can receive and cool the reacted material. The cooling tank 400 can be used to cool the reacted material, eliminating the need for cooling in the fluidized bed reactor 200. Since the fluidized bed reactor 200 is a high-temperature device, it takes a long time to achieve the desired cooling effect, and it also leads to intermittent production of the fluidized bed reactor 200. Therefore, the use of the cooling tank 400 in this application can reduce the overall system operating time and improve operating efficiency.

[0089] The cooling tank 400 is connected to the outlet of the fluidized bed reactor 200 in the reaction zone 200b via a feed pipe, and the feed pipe is equipped with a discharge valve 270. The discharge valve 270 and the feed pipe should be made of high-temperature materials with a temperature resistance of 700~1000℃.

[0090] In one embodiment, such as Figure 1 As shown, a cooling water jacket 410 is provided on the outer periphery of the cooling tank 400. The cooling water jacket 410 has a circulating water inlet and a circulating water outlet. Circulating water can be injected into the cooling water jacket 410 through the circulating water inlet to cool the reacted materials.

[0091] In one embodiment, such as Figure 1 As shown, the cooling tank 400 is equipped with a second stirring mechanism 440, which can stir the materials in the cooling tank 400. The second stirring mechanism 440 can accelerate the cooling of the materials after the reaction. The second stirring mechanism 440 can have the same structure as the first stirring mechanism 130, or it can be different.

[0092] In one embodiment, such as Figure 1 As shown, the discharge port of the cooling tank 400 is equipped with a discharge valve 450. The fluidized bed reaction system also includes a fourth detector 460. The fourth detector 460 is electrically connected to the control component and can detect the temperature information of the cooling tank 400. The control component is electrically connected to the discharge valve 450 and can open the discharge valve 450 when the temperature of the cooling tank 400 is lower than a fourth preset value. Through the cooperation of the fourth detector 460 and the control component, the automation level of the entire system can be improved. The fourth detector 460 can be a temperature sensor.

[0093] The preparation process of silicon-carbon anode materials is described below based on the fluidized bed reaction system described above:

[0094] First, porous carbon is added to the drying tank 100. The valve on the nitrogen inlet of the dryer 100 is opened, and nitrogen is introduced into the material chamber to pressurize it to 0.1 MPaG. Then, the valve on the exhaust port of the dryer 100 is opened to release the pressure and replace the air in the material chamber. This operation is repeated 5 to 10 times. Then, the heating element 150 on the dryer 100 is turned on to dry the raw material in the material chamber. After drying, the first material valve 110 and the second material valve 120 are opened. The dried material falls into the sending chamber 160 and is then transported to the reaction zone 200b of the fluidized bed reactor 200. During the feeding process of the fluidized bed reactor 200, process gas (e.g., nitrogen) and fluidizing gas (e.g., nitrogen) are introduced into the fluidized bed reactor 200 to fluidize the material.

[0095] Then, the temperature inside the fluidized bed reactor 200 is controlled at 400℃~600℃, and the pressure is controlled between 0.005MPaG~0.2MPaG. The process gas is controlled as a mixture of nitrogen and silane, with a molar concentration of silane of 5%~30%, and the deposition time is 2~15h. Subsequently, the first inlet pipe 231 switches the mixture of nitrogen and silane to nitrogen only. Then, the temperature inside the reactor is controlled at 500℃~800℃, and the pressure is controlled between 0.005MPaG~0.2MPaG. The process gas is switched from nitrogen only to a mixture of nitrogen and acetylene, with a molar concentration of acetylene of 5%~30%, and the deposition time is 1~5h, thus obtaining the silicon-carbon anode material.

[0096] Finally, after the reaction is complete, the fluidized bed reactor 200 is pressurized and the discharge valve 270 is opened to send the product to the cooling tank 400 for cooling.

[0097] 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.

[0098] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fluidized bed reaction system for silicon-carbon anode materials, characterized in that, include: A drying tank having a material chamber, the drying tank being able to dry the material in the material chamber and also being able to deliver a displacement gas into the material chamber to replace the gas in the material chamber; A fluidized bed reactor has, from top to bottom, a gas-solid separation zone, a reaction zone, and an initial fluidization zone. The reaction zone is connected to the material chamber to receive the dried material. The fluidized bed reactor has a first inlet pipe and a second inlet pipe. The first inlet pipe is connected to the reaction zone to supply process gas to the reaction zone, and the second inlet pipe is connected to the initial fluidization zone to supply fluidizing gas to the initial fluidization zone. The first inlet pipe is located away from the second inlet pipe. The fluidized bed reactor has a fluidization distribution plate at the boundary between the reaction zone and the initial fluidization zone. The fluidization distribution plate has multiple second air holes, and the end of the second inlet pipe extends into the initial fluidization zone and faces downward. The fluidized bed reactor also has a third inlet pipe, which is connected to the initial fluidization zone to intermittently supply motive gas. The pressure of the motive gas is greater than the pressure of the fluidizing gas. The discharge tank has a dust removal chamber, which is connected to the gas-solid separation zone through a discharge pipe. The discharge pipe is equipped with a bursting component. When the pressure inside the fluidized bed reactor exceeds a first preset value, the bursting component can rupture to release the gas inside the fluidized bed reactor. At the same time, the powder inside the fluidized bed reactor can be discharged into the washing liquid in the dust removal chamber through the discharge pipe.

2. The fluidized bed reaction system for silicon-carbon anode materials according to claim 1, characterized in that, The bottom of the drying tank has a discharge port that communicates with the reaction zone; The discharge port is provided with a first material valve and a second material valve in sequence along the discharge direction, and the second material valve is a star-shaped discharge valve.

3. The fluidized bed reaction system for silicon-carbon anode materials according to claim 2, characterized in that, The drying tank is also provided with an exhaust port that communicates with the material chamber; The drying tank of the fluidized bed reaction system for silicon-carbon anode materials also includes a control component and a first detector. The first detector, the first material valve, and the second material valve are all electrically connected to the control component. The first detector can detect the oxygen content at the exhaust port. When the oxygen content at the exhaust port is lower than a second preset value, the control component can open the first material valve and the second material valve to discharge the dried material from the discharge port.

4. The fluidized bed reaction system for silicon-carbon anode materials according to claim 1, characterized in that, The silicon-carbon anode material fluidized bed reaction system also includes at least one of the following features: The drying tank is equipped with a first stirring mechanism, which is capable of stirring the material in the material chamber. The drying tank is equipped with a second detector, which can detect the weight of the material in the material chamber; The end of the discharge pipe that extends into the dust removal chamber is equipped with a horn nozzle; The top of the discharge tank is equipped with a baffle plate, and the end of the discharge pipe is sealed through the baffle plate; The top of the discharge tank is provided with a water inlet that communicates with the dust removal chamber.

5. The fluidized bed reaction system according to any one of claims 1 to 4, characterized in that, The fluidized bed reactor is equipped with a first filter assembly at the top of the gas-solid separation zone, which is capable of filtering fluidized particles in the gas.

6. The fluidized bed reaction system according to claim 5, characterized in that, The fluidized bed reaction system for silicon-carbon anode materials also includes a third detector, a control component, and a backflushing component; The third detector is electrically connected to the control component and is capable of detecting the pressure difference between the inlet and outlet of the first filter component; The backflush assembly is located in the fluidized bed reactor and is electrically connected to the control assembly; The control component can control the backflushing component to backflush the first filter component when the pressure difference between the inlet and outlet of the first filter component is higher than a third preset value, so as to cause the fluidized particles to detach from the first filter component.

7. The fluidized bed reaction system for silicon-carbon anode materials according to any one of claims 1 to 4, characterized in that, The fluidized bed reactor is equipped with an annular distributor that extends into the reaction zone and is connected to the outlet of the first air inlet pipe. The annular distributor has multiple first air holes.

8. The fluidized bed reaction system for silicon-carbon anode materials according to any one of claims 1 to 4, characterized in that, The fluidized bed reaction system also includes a cooling tank connected to the reaction zone, which is capable of receiving and cooling the reacted materials.

9. The fluidized bed reaction system for silicon-carbon anode materials according to claim 8, characterized in that, The silicon-carbon anode material fluidized bed reaction system also includes at least one of the following features: The outer periphery of the cooling tank is provided with a cooling water jacket, and the cooling water jacket is connected to an inlet pipe and a drain pipe. The cooling tank is equipped with a second stirring mechanism, which is capable of stirring the material in the cooling tank; The cooling tank is equipped with a discharge valve at its discharge port. The fluidized bed reaction system also includes a fourth detector and a control component. The fourth detector is electrically connected to the control component and can detect the temperature information of the cooling tank. The control component is electrically connected to the discharge valve and can open the discharge valve when the temperature of the cooling tank is lower than a fourth preset value.

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