Continuous silicon carbide powder production system

Abstract

The utility model relates to the technical field of chemical engineering, in particular to a continuous production system for silicon carbide powder, comprising: a feeding tank for storing silicon carbide seed crystals; a first feeding port is formed in the top of the fluidized bed, and a second feeding port and a discharging port are formed in the bottom of the fluidized bed; the fluidized bed heater is used for heating the fluidized bed; a gas raw material storage tank in which a gas raw material is stored; and a finished product tank; wherein the outlet end of the feeding tank is connected with a first feeding port on the fluidized bed through a first pipeline; the outlet end of the gas raw material storage tank is connected with a second feeding port in the fluidized bed through a second pipeline; the inlet end of the finished product tank is connected with the discharge port of the fluidized bed through a third pipeline, and after the silicon carbide seed crystals in the fluidized bed grow to the required particle size, the silicon carbide seed crystals are discharged from the discharge port under the action of self gravity and enter the finished product tank through the third pipeline.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, and more specifically, to a continuous production system for silicon carbide powder. Background Technology

[0002] Silicon carbide is a typical representative of third-generation semiconductor materials, possessing advantages such as high electron mobility, wide bandgap, high voltage withstand capability, high thermal conductivity, and strong radiation resistance. This has directly driven the rapid development of a series of industries, including semiconductor lighting, displays, and electric vehicles. Furthermore, silicon carbide materials are suitable for high-temperature, high-frequency, high-power, and highly corrosive environments, and have wide applications in machinery, electronics, chemicals, and energy fields.

[0003] The fluidized bed reactor for silicon-carbon anode materials uses porous carbon as raw material. Through the full fluidization of the material within the reactor and the high-temperature pyrolysis of silane gases, amorphous silicon is generated from the pores of the porous carbon, ultimately achieving silicon-carbon bonding to form a novel anode material, silicon carbide. Generally, fluidized bed reactors mostly adopt a slender cylindrical structure, vertically arranged, and achieve material fluidization and process gas pyrolysis and deposition through bottom air inlet and sidewall heating.

[0004] Chinese utility model patent application CN 106082227 A discloses a fluidized bed chemical vapor deposition method for preparing silicon carbide nanoparticles. This method uses hexamethyldisilane as a raw material and hydrogen and argon as carrier gases, generating silicon carbide particles with adjustable sizes through thermal decomposition in a fluidized bed. The advantages of this method are its simplicity and ease of operation. However, this method requires negative pressure extraction during discharge, which limits production capacity due to the volume of the fluidized bed. Once a certain amount of material is reached in the fluidized bed, the reaction must be stopped, the temperature lowered, and then the material discharged. If the powder is not discharged in time, it will accumulate, potentially resulting in excessively large particles and uneven particle size, affecting its application.

[0005] Chinese utility model patent application CN 119113938 A discloses a fluidized bed reaction system for silicon-carbon anode materials. This system includes a raw material conveying system, a fluidized bed reactor, a high-temperature discharge system, a process gas inlet pipeline, and a protection system. After solid raw materials are added to the raw material conveying tank, they are conveyed to the fluidized bed under positive pressure. Gas is introduced at the bottom of the fluidized bed, and a gas-solid separator is installed at the top. After the reaction, the solids inside the fluidized bed can be directly compressed into the finished product tank without cooling. Furthermore, a horn-shaped discharge elbow is provided at the bottom of the raw material conveying tank, which facilitates solid discharge. Although this system overcomes the problem of needing to cool the material before discharge, the discharge still requires stopping the fluidized bed reaction and then conveying it to the finished product tank under positive pressure, making the discharge process complex and preventing continuous production. Utility Model Content

[0006] The main objective of this invention is to propose a production system capable of continuous production of silicon carbide powder.

[0007] To solve the above-mentioned technical problems, this utility model proposes a continuous silicon carbide powder production system, comprising:

[0008] Feeding tank, used to store silicon carbide seed crystals;

[0009] A fluidized bed has a first feed port at the top, a second feed port at the bottom, and a discharge port.

[0010] Fluidized bed heater, used to heat a fluidized bed;

[0011] A gaseous raw material storage tank that stores gaseous raw materials;

[0012] And finished product cans;

[0013] The outlet of the feeding tank is connected to the first feed port of the fluidized bed through a first pipe; the outlet of the gas raw material storage tank is connected to the second feed port of the fluidized bed through a second pipe; the inlet of the finished product tank is connected to the outlet port of the fluidized bed through a third pipe, and after the silicon carbide seed crystals in the fluidized bed grow to the required particle size, they are discharged from the outlet port under their own gravity and enter the finished product tank through the third pipe.

[0014] In the above technical solution, the fluidized bed and the finished product tank are arranged vertically.

[0015] In any of the above technical solutions, further comprising:

[0016] The trap is positioned above the fluidized bed to capture and intercept small particles within the fluidized bed.

[0017] In any of the above technical solutions, the fluidized bed is further divided into a two-stage segmented structure with a larger upper section and a smaller lower section, and is divided into an upper small particle growth zone and a lower large particle growth zone.

[0018] The trap is located in the small particle growth zone of the fluidized bed.

[0019] In any of the above technical solutions, further comprising:

[0020] The exhaust gas cooler is used to cool the exhaust gas discharged from the fluidized bed and the collector.

[0021] In any of the above technical solutions, further comprising:

[0022] The preheater, located on the second pipeline, is used to preheat the gas discharged from the gas raw material storage tank before discharging it to the fluidized bed.

[0023] In any of the above technical solutions, the preheater further includes:

[0024] The outer tube has an inlet and an outlet at its two ends;

[0025] The inner tube is set inside the outer tube and extends along the length of the outer tube. There are multiple inner tubes, which are arranged around the inner wall of the outer tube in a circumferential manner.

[0026] And heating units, of which there are several, and each is disposed in an inner tube;

[0027] The inner tubes form a preheating channel in the middle after they are enclosed, and the inlet and outlet of the outer tube and the preheating channel are on the same straight line.

[0028] In any of the above technical solutions, a cooling water pipe is further provided on the finished product tank.

[0029] In any of the above technical solutions, further comprising:

[0030] The replacement system uses nitrogen and argon gas sequentially to replace the air in the feeding tank, fluidized bed, and finished product tank.

[0031] Beneficial effects: Compared with the prior art, this application installs a finished product tank at the bottom of the fluidized bed, which can achieve continuous product output without affecting fluidized bed production, enabling long-term continuous operation, which is more conducive to industrial preparation. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart illustrating the present invention.

[0034] Figure 2 This is a three-dimensional structural diagram of the preheater of this utility model;

[0035] Figure 3 This is a schematic diagram of the internal structure of the preheater of this utility model;

[0036] Figure 4 yes Figure 3 An enlarged structural diagram at point A in the middle;

[0037] Figure 5 This is a schematic diagram of the internal structure of the preheater of this utility model from another perspective.

[0038] The annotations in the attached figures are explained as follows:

[0039] 1. Feeding tank; 2. Fluidized bed; 21. First feed port; 22. Second feed port; 23. Discharge port; 201. Small particle growth zone; 202. Large particle growth zone; 3. Fluidized bed heater; 4. Gas raw material storage tank; 5. Finished product tank; 6. Collector; 7. Tail gas cooler; 8. Preheater; 81. Outer pipe; 82. Inner pipe; 83. Heating unit; 831. Sleeve; 832. Heater; 84. Preheating channel; 85. Mounting frame; 851. Connecting rod; 9. Cooling water pipe; 10. Nitrogen delivery pipe; 20. Argon delivery pipe. Detailed Implementation

[0040] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0041] It should be noted that, as shown in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list; the method or apparatus may also include other steps or elements.

[0042] If the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0043] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0044] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0045] like Figures 1-5 As shown, this application proposes a continuous silicon carbide powder production system, including: a feeding tank 1 for storing silicon carbide seed crystals; a fluidized bed 2 having a first feed port 21 at the top, a second feed port 22 at the bottom, and a discharge port 23; a fluidized bed heater 832 for heating the fluidized bed 2; a gaseous raw material storage tank 4 for storing gaseous raw materials; and a finished product tank 5.

[0046] The outlet of the feeding tank 1 is connected to the first feed port 21 on the fluidized bed 2 via a first pipe; the outlet of the gas raw material storage tank 4 is connected to the second feed port 22 on the fluidized bed 2 via a second pipe; the inlet of the finished product tank 5 is connected to the discharge port 23 of the fluidized bed 2 via a third pipe, and after the silicon carbide seed crystals in the fluidized bed 2 grow to the required particle size, they are discharged from the discharge port 23 under their own gravity and enter the finished product tank 5 through the third pipe.

[0047] Currently, existing production systems for silicon carbide production cannot achieve continuous production. To address this, this application provides a discharge port 23 at the bottom of the fluidized bed 2 for unloading, and the inlet of the finished product tank 5 is directly connected to the discharge port 23 of the fluidized bed 2. When the silicon carbide gradually grows to a certain size in the fluidized bed 2, it will fall downwards under the action of gravity and into the finished product tank 5. This achieves continuous production on the one hand, and avoids excessive filling in the fluidized bed 2 on the other hand.

[0048] It should be noted that after a large amount of material accumulates in the finished product tank 5, the discharge valve at the discharge port 23 on the fluidized bed 2 can be temporarily closed to transport the material in the finished product tank 5 outwards. The discharge valve can then be reopened to allow the fluidized bed 2 to continue production.

[0049] It should be noted that the fluidized bed 2 and the finished product tank 5 are arranged vertically to facilitate the smooth falling of the formed silicon carbide in the fluidized bed 2 into the finished product tank 5.

[0050] It should be noted that it also includes: a replacement system, which uses nitrogen and argon to replace the air in the feeding tank 1, the fluidized bed 2 and the finished product tank 5 in sequence.

[0051] The replacement system mainly consists of an argon gas delivery pipe 20 and a nitrogen gas delivery pipe 10. The argon gas delivery pipe 20 and the nitrogen gas delivery pipe 10 are connected to the feeding tank 1, the fluidized bed 2, and the finished product tank 5 through gas pipes. First, the nitrogen gas delivery pipe 10 is opened to purge air through nitrogen. Then, the argon gas delivery pipe 20 is opened to deliver argon gas. Under the action of inert gas, the oxygen content inside the feeding tank 1, the fluidized bed 2, and the finished product tank 5 can be effectively reduced, preventing oxidation reactions caused by the presence of oxygen.

[0052] It should be noted that, since nitrogen is less expensive, the air is first replaced with nitrogen, and then replaced with argon to provide a more stable reaction environment.

[0053] In an optimized version, this application also includes: a trap 6, disposed above the fluidized bed 2, for trapping and intercepting small particles above the fluidized bed 2.

[0054] The trap 6 is a device used to capture particulate matter. During the reaction of silicon carbide seed crystals in the fluidized bed 2, small particles are above the fluidized bed 2 under the influence of gravity, while large particles are below the fluidized bed 2. Some small particles are emitted with the exhaust gas, resulting in material waste. Therefore, the trap 6 is installed to intercept small particles near the exhaust gas outlet.

[0055] The optimized fluidized bed 2 has a two-stage segmented structure with a larger upper part and a smaller lower part, and is divided into an upper small particle growth zone 201 and a lower large particle growth zone 202.

[0056] Among them, the trap 6 is located in the small particle growth zone 201 of the fluidized bed 2.

[0057] By adopting a two-stage segmented fluidized bed 2, large particles can continue to grow at a higher flow rate, while small particles can grow at a lower flow rate. This effectively prevents small particles from being blown away to the collector 6, reduces the backflush frequency of the collector 6, and improves product yield.

[0058] The optimization also includes an exhaust gas cooler 7, used to cool the exhaust gas discharged from the fluidized bed 2 and the collector 6. The exhaust gas discharged from the fluidized bed 2 is high-temperature exhaust gas. If the high-temperature exhaust gas is directly discharged, it may cause thermal damage to the equipment and increase environmental pollution. Through the cooling treatment of the exhaust gas cooler 7, the temperature of the exhaust gas can be effectively reduced to meet the safe emission standards.

[0059] The optimization also includes: a preheater 8, which is installed on the second pipeline to preheat the gas discharged from the gas raw material storage tank 4 before discharging it to the fluidized bed 2.

[0060] To avoid the raw material gas at room temperature affecting the reaction rate, a preheater 8 is installed in this process to preheat the raw material gas.

[0061] Specifically, the preheater 8 includes: an outer tube 81 with an inlet and an outlet at its two ends; an inner tube 82 disposed inside the outer tube 81 and extending along the length of the outer tube 81, and there are multiple inner tubes 82 arranged circumferentially around the inner wall of the outer tube 81; and heating units 83, having several units, and disposed inside each inner tube 82.

[0062] Among them, after the inner tubes 82 are enclosed, a preheating channel 84 is formed in the middle, and the inlet and outlet of the outer tube 81 and the preheating channel 84 are on the same straight line.

[0063] The outer tube 81 is cylindrical, with its inlet and outlet ends having cylindrical structures to facilitate pipe connection; the inner tube 82 is cylindrical. The inner tube 82 serves as the outer shell structure for installing the heating unit 83. Furthermore, by arranging the inner tubes 82 in a circular manner, a chamber is formed in the middle of each inner tube 82. This chamber is the preheating channel 84. Gas enters through the inlet on the outer tube 81, then passes through the preheating channel 84, is preheated within the preheating channel 84, and finally exits from the outlet on the outer tube 81.

[0064] It should be noted that by setting the inlet, outlet and preheating channel 84 on the same straight line, this embodiment not only effectively improves its exhaust performance, but also effectively improves the gas heating effect by arranging the heating unit 83 around the preheating channel 84, and also makes the gas heated evenly.

[0065] It should be noted that, in order to ensure the inner diameter of the preheating channel 84, the number of inner tubes 82 is set to at least five, and each inner tube 82 is evenly distributed, and the outer walls of adjacent inner tubes 82 abut against each other in sequence, so that the preheating channel 84 is a sealed channel in the circumferential direction.

[0066] It should be noted that the inner tube 82 is a heat-conducting tube made of heat-conducting material, so as to transfer the heat generated by the heating unit 83 to the preheating channel 84, thereby heating the gas in the preheating channel 84.

[0067] The preheater 8 also includes: a mounting bracket 85 for connecting and fixing each inner tube 82. There are two sets of mounting brackets 85, which are respectively arranged on both sides of the inner tube 82.

[0068] The mounting bracket 85 has several mounting holes, and the end of the inner tube 82 passes through the mounting holes.

[0069] In order to securely install the inner tube 82 inside the outer tube 81, a mounting bracket 85 is provided. Mounting holes are made on the mounting bracket 85, and the end of the inner tube 82 is then inserted into the mounting hole of the mounting bracket 85. This ensures that the inner tubes 82 do not become loose, thus guaranteeing the stability of the preheating channel 84.

[0070] It should be noted that the mounting bracket 85 has a disc-shaped structure, and the mounting holes are arranged along the circumferential direction of the disc. The number of mounting holes is the same as the number of inner tubes 82.

[0071] It should be noted that there is an annular groove on the outer wall of the end of the inner tube 82, which is opened radially inward. After the end of the inner tube 82 passes through the mounting hole of the mounting bracket 85, it abuts against the mounting bracket 85.

[0072] The optimized preheater 8 also includes two connecting rods 851, used to connect two mounting brackets 85, fixing the two mounting brackets 85 to both ends of the inner tube 82. Each inner tube 82 is securely mounted on the mounting bracket 85. The mounting bracket 85 can be directly embedded into the inner tube 82 when installed in the outer tube 81. However, this method makes the mounting bracket 85 easy to move in the outer tube 81. Therefore, the connecting rods 851 are provided. The connecting rods 851 are detachable structures. The two mounting brackets 85 are connected by the connecting rods 851, thus fixing the two mounting brackets 85. This not only increases the firmness of the installation between the mounting bracket 85 and the inner tube 82, but also ensures the stability of the mounting bracket 85 in the outer tube 81.

[0073] It should be noted that the connecting rod 851 is a screw structure, with internal threaded holes on the mounting bracket 85. Both ends of the connecting rod 851 are threaded into the internal threaded holes of the two mounting brackets 85, respectively. For ease of installation, the connecting rod 851 is designed as a T-shaped screw, with a ring-shaped end for easy hand-rotation by the operator.

[0074] It should be noted that the outlet on the outer tube 81 is a detachable conical structure, which is installed on the outer tube 81 by means of threaded connection. When installing the internal structure of the preheating device, the outlet is first removed, and then the inner tube 82, mounting bracket 85 and other structures are inserted into the outer tube. After the outlet is installed on the outer tube 81, the inner port of the outlet is pressed against the inner tube 82 and the mounting bracket 85 to prevent it from moving along the length of the outer tube 81.

[0075] It should be noted that the heating unit 83 includes: a sleeve 831; and a heater 832, which is disposed inside the sleeve 831 and is used to provide heat to heat the gas located in the preheating channel 84.

[0076] The heater 832 mainly consists of a long strip-shaped ceramic coil frame, on which a heating wire and a controller are wound to control the heating temperature of the heating wire. A temperature sensor is installed on the outer wall of the sleeve 831 to detect the temperature of the inner tube 82. The controller controls the current passing through the heating wire based on the temperature signal detected by the temperature sensor, thereby controlling the heating temperature of the heating wire.

[0077] The optimized product tank 5 is equipped with a cooling water pipe 9. By continuously supplying cooling water into the cooling water pipe 9, the temperature of the product tank 5 is reduced, thereby lowering the temperature of the silicon carbide powder inside.

[0078] The following examples illustrate the production of silicon carbide powder. Example 1:

[0079] 1) Place a 3μm silicon carbide seed crystal into the feeding tank, and then use a displacement system to replace the air in the feeding tank with nitrogen and argon in sequence.

[0080] 2) Using a displacement system, the air in the fluidized bed is replaced sequentially with nitrogen and argon, while maintaining an argon flow rate of 30 L / min at the bottom of the fluidized bed.

[0081] 3) Press the silicon carbide seed crystal in the feeding tank into the fluidized bed. The fluidized bed pressure is atmospheric pressure.

[0082] 4) Turn on the preheater and maintain its outlet temperature at 100℃. Turn on the fluidized bed heater and raise the temperature to 700℃. After the temperature reaches 700℃, maintain it for 30 minutes. Then, adjust the methylsilane flow rate to 5L / min, the argon flow rate to 30L / min, and the hydrogen flow rate to 30L / min.

[0083] 5) The reaction continued for 4 hours, and the silicon carbide product was collected in the finished product tank. Its particle size was 58 μm, and chemical analysis according to GB / T 3045-2017 showed that the silicon carbide purity was 99.25%.

[0084] Example 2:

[0085] 1) Place a 5μm silicon carbide seed crystal into the feeding tank, and then use a displacement system to replace the air in the feeding tank with nitrogen and argon in sequence.

[0086] 2) Using a displacement system, the air in the fluidized bed is replaced sequentially with nitrogen and argon, while maintaining an argon flow rate of 40 L / min at the bottom of the fluidized bed.

[0087] 3) Press the silicon carbide seed crystal in the feeding tank into the fluidized bed. The fluidized bed pressure is atmospheric pressure.

[0088] 4) Turn on the preheater and maintain the outlet temperature at 100℃. Turn on the fluidized bed heater and raise the temperature to 1200℃. After the temperature reaches 1200℃, maintain it for 30 minutes. Then, adjust the methylsilane flow rate to 5L / min, the argon flow rate to 50L / min, and the hydrogen flow rate to 30L / min.

[0089] 5) The reaction continued for 4 hours, and the silicon carbide product was collected in the finished product tank. The particle size was 64 μm, and chemical analysis according to GB / T3045-2017 showed that the silicon carbide purity was 99.58%.

[0090] Example 3:

[0091] 1) Place a 10μm silicon carbide seed crystal into the feeding tank, and then use a displacement system to replace the air in the feeding tank with nitrogen and argon in sequence.

[0092] 2) Using a displacement system, the air in the fluidized bed is replaced sequentially with nitrogen and argon, while maintaining an argon flow rate of 60 L / min at the bottom of the fluidized bed.

[0093] 3) Press the silicon carbide seed crystal in the feeding tank into the fluidized bed, and control the fluidized bed pressure to 6 bar (gauge pressure).

[0094] 4) Turn on the preheater and maintain the outlet temperature at 100℃. Turn on the fluidized bed heater and raise the temperature to 1600℃. After the temperature reaches 1600℃, maintain it for 30 minutes, then adjust the methylsilane flow rate to 5L / min and the argon flow rate to 100L / min.

[0095] 5) The reaction continued for 4 hours, and the silicon carbide product was collected in the finished product tank. The particle size was 105 μm, and chemical analysis according to GB / T 3045-2017 showed that the silicon carbide purity was 99.11%.

[0096] Example 4:

[0097] 1) Place a 1μm silicon carbide seed crystal into the feeding tank, and then use a displacement system to replace the air in the feeding tank with nitrogen and argon in sequence.

[0098] 2) Using a displacement system, the air in the fluidized bed is replaced sequentially with nitrogen and argon, while maintaining an argon flow rate of 20 L / min at the bottom of the fluidized bed.

[0099] 3) Press the silicon carbide seed crystal in the feeding tank into the fluidized bed, and control the fluidized bed pressure to 3 bar (gauge pressure).

[0100] 4) Turn on the preheater and maintain the outlet temperature at 100℃. Turn on the fluidized bed heater and raise the temperature to 900℃. After the temperature reaches 900℃, maintain it for 30 minutes, then adjust the methylsilane flow rate to 5L / min and the hydrogen flow rate to 50L / min.

[0101] 5) The reaction continued for 4 hours, and the silicon carbide product was collected in the finished product tank. The particle size was 52 μm, and chemical analysis according to GB / T3045-2017 showed that the silicon carbide purity was 99.42%.

[0102] This application has at least the following technical effects.

[0103] This application uses methylsilane as a raw material to produce silicon carbide, which generates no corrosive tail gas, has high atom utilization, and is more economical and environmentally friendly. Furthermore, it uses only one raw material besides the carrier gas, making the operation simple. Using one or more of methylsilane, dimethylsilane, and trimethylsilane as raw materials to synthesize silicon carbide can also yield the same results, but the raw material utilization rate will be somewhat lower.

[0104] This application describes the preparation of silicon carbide powder using a fluidized bed method, which results in high production efficiency and uniform and controllable particle size.

[0105] Installing a finished product tank at the bottom of the fluidized bed allows for continuous product output without affecting fluidized bed production, enabling long-term continuous operation and facilitating industrial-scale preparation.

[0106] This application has a wide operating temperature range, down to 700℃, which can effectively reduce production energy consumption and save production costs.

[0107] This application incorporates small-diameter seed crystals, which is more conducive to the growth of silicon carbide, avoids the initial small-diameter particles being carried away and consumed, and, combined with the recovery of the trap, effectively improves the product yield.

[0108] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A continuous silicon carbide powder production system, characterized by, The application relates to a silicon carbide seed crystal production system, which comprises: a feeding tank (1) for storing silicon carbide seed crystals; a fluidized bed (2) with a first feeding port (21) at the top, a second feeding port (22) at the bottom and a discharging port (23); a fluidized bed heater (832) for heating the fluidized bed (2); a gas raw material storage tank (4) for storing gas raw materials; and a finished product tank (5); wherein the outlet end of the feeding tank (1) is connected with the first feeding port (21) of the fluidized bed (2) through a first pipeline; the outlet end of the gas raw material storage tank (4) is connected with the second feeding port (22) of the fluidized bed (2) through a second pipeline; and the inlet end of the finished product tank (5) is connected with the discharging port of the fluidized bed (2) through a third pipeline, and the silicon carbide seed crystals in the fluidized bed (2) are discharged from the discharging port (23) under the action of gravity and then enter the finished product tank (5) through the third pipeline when the silicon carbide seed crystals grow to the required particle size.

2. The continuous silicon carbide powder production system of claim 1, wherein, The fluidized bed (2) and the finished product tank (5) are arranged in an up-down mode.

3. The continuous silicon carbide powder production system of claim 1, wherein, Further comprising: a catcher (6) arranged above the fluidized bed (2) and used for capturing and intercepting small particles in the upper part of the fluidized bed (2).

4. The continuous silicon carbide powder production system of claim 3, wherein, The fluidized bed (2) is a two-stage segmented structure with the upper part being large and the lower part being small, and is divided into an upper small particle growth area (201) and a lower large particle growth area (202); wherein the catcher (6) is located in the small particle growth area (201) of the fluidized bed (2).

5. The continuous silicon carbide powder production system of claim 4, wherein, Further comprising: an exhaust gas cooler (7) used for cooling exhaust gas discharged from the fluidized bed (2) and the catcher (6).

6. The continuous silicon carbide powder production system of claim 1, wherein, Further comprising: a preheater (8) arranged on the second pipeline and used for preheating gas discharged from the gas raw material storage tank (4) and then discharging the preheated gas to the fluidized bed (2).

7. The continuous silicon carbide powder production system of claim 6, wherein, The preheater (8) comprises: an outer pipe (81) with an inlet and an outlet formed at two ends thereof; an inner pipe (82) arranged in the outer pipe (81) and extending along the length direction of the outer pipe (81), wherein a plurality of inner pipes (82) are arranged in a circumferential mode along the inner wall of the outer pipe (81); and a heating unit (83) arranged in each inner pipe (82); wherein the inner pipes (82) are enclosed to form a preheating channel (84) in the middle part, and the inlet and the outlet of the outer pipe (81) and the preheating channel (84) are arranged on the same straight line.

8. The continuous silicon carbide powder production system of claim 1, wherein, A cooling water pipe (9) is arranged on the finished product tank (5).

9. The continuous silicon carbide powder production system of any one of claims 1-8, wherein, Further comprising: a replacement system for replacing air in the feeding tank (1), the fluidized bed (2) and the finished product tank (5) with nitrogen and argon in sequence.

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