Method and device for synthesizing silicon carbide powder

Abstract

The embodiment of the invention provides a silicon carbide powder synthesis method and device, relates to the technical field of silicon carbide powder synthesis, and aims at solving the technical problems that in the existing silicon carbide synthesis process, the recovery efficiency of escaped gas phase silicon is low, and the recovery effect is not ideal. The method comprises the following steps that S1, synthetic raw materials are contained in a crucible, and the synthetic raw materials comprise carbon powder and silicon powder; s2, heating the crucible to sublimate the silicon powder and form gas-phase silicon; wherein one part of the gas-phase silicon reacts with the carbon powder to form silicon carbide, and the other part of the gas-phase silicon volatilizes and escapes; and S3, recovering the dissipated gas-phase silicon, so that the dissipated gas-phase silicon participates in the reaction again and forms silicon carbide until the synthesis process of the silicon carbide powder is finished. According to the invention, in-situ recovery is carried out on the gas-phase silicon escaping into the recovery area, so that the silicon source recovery efficiency is relatively high.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide powder synthesis technology, and more specifically, to a method and apparatus for synthesizing silicon carbide powder. Background Technology

[0002] During the synthesis of silicon carbide, solid silicon sources (such as silicon powder) escape from the reaction zone after forming gaseous silicon, resulting in silicon loss. Silicon loss can typically reach 5%-15%, thereby increasing costs and environmental impact.

[0003] In existing technologies, external traps are typically used to recover the escaping gaseous silicon, but the recovery efficiency is low and the recovery effect is not ideal. Summary of the Invention

[0004] The present invention aims to provide a method and apparatus for synthesizing silicon carbide powder, so as to improve the technical problem of low recovery efficiency and unsatisfactory recovery effect of the escaping gaseous silicon in the existing silicon carbide synthesis process.

[0005] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a method for synthesizing silicon carbide powder, comprising: The raw materials for synthesis are placed in a crucible, and the raw materials include carbon powder and silicon powder. The crucible is heated so that the silicon powder sublimates and forms gaseous silicon; a portion of the gaseous silicon reacts with the carbon powder to form silicon carbide, while the other portion of the gaseous silicon volatilizes and dissipates. The escaped fumed silicon is recovered and allowed to participate in the reaction again to form silicon carbide until the silicon carbide powder synthesis process is completed.

[0006] In an optional implementation, the method for recovering the escaped fumed silicon is as follows: The escaped gaseous silicon is liquefied to form liquid silicon, which is then recovered under gravity and participates in the reaction again to form silicon carbide.

[0007] In a second aspect, the present invention provides a silicon carbide powder synthesis apparatus, comprising: A crucible, comprising a crucible body and a crucible lid covering the crucible body, the crucible body and the crucible lid jointly defining a connected reaction zone and a recovery zone; wherein, the reaction zone contains synthetic raw materials, the synthetic raw materials including solid carbon powder and silicon powder; A heating element is arranged around the outside of the crucible body, and silicon powder sublimates and forms gaseous silicon under the action of the heating element; A condenser plate is disposed in the recovery zone. Under the action of the condenser plate, the gaseous silicon is liquefied and forms liquid silicon in the recovery zone. The liquid silicon is recovered to the reaction zone under the action of gravity.

[0008] In an optional embodiment, the condensing plate is disposed on the crucible lid, and the condensing plate includes a plate body, cooling channels formed on the plate body, and a gas collecting groove disposed around the plate body; Cooling medium is introduced into the cooling channel, and the cooling channel has an input end and an output end; wherein, the input end of the cooling channel is connected to a medium input pipe, the output end of the cooling channel is connected to the gas collection tank, and the gas collection tank is connected to a medium output pipe.

[0009] In an optional embodiment, the cooling channel includes multiple main cooling channels, one end of each main cooling channel is connected to the medium input pipe, and the other end of each main cooling channel is connected to multiple branch cooling channels, the end of each branch cooling channel away from the main cooling channel is connected to the gas collection groove.

[0010] In an optional implementation, the plurality of main cooling channels and branch cooling channels are arranged radially.

[0011] In an optional embodiment, a heat insulation plate is provided between the condenser plate and the crucible lid.

[0012] In an optional embodiment, a plurality of flow guides are arranged in an array on the surface of the condenser plate near the synthetic raw material; The flow guide includes a flow guide surface and at least one sharp portion. Vaporized silicon can be liquefied on the flow guide surface to form liquid silicon. Liquid silicon can accumulate at the sharp portion and be recycled back to the reaction zone under the action of gravity.

[0013] In an optional embodiment, the flow guide is conical or pyramidal in shape.

[0014] In an optional embodiment, the reaction zone is arrayed with a plurality of collection tubes with openings at both ends, and the plurality of collection tubes are correspondingly arranged with a plurality of flow guides; One end of the collection tube is buried in the synthetic raw material, and the other end of the collection tube extends into the recycling area.

[0015] The beneficial effects of the silicon carbide powder synthesis method and apparatus provided in this invention include: The silicon carbide powder synthesis method provided by this invention involves placing the synthesis raw materials in a crucible, heating the crucible to sublimate the silicon powder and form fumed silicon. A portion of the fumed silicon reacts with the carbon powder in the reaction zone to form silicon carbide, while another portion escapes the reaction zone and enters a recovery zone. By recovering the fumed silicon in the recovery zone, the escaped fumed silicon participates in the reaction again to form silicon carbide, until the silicon carbide powder synthesis process is completed. This invention achieves high silicon source recovery efficiency through in-situ recovery of the fumed silicon that escapes into the recovery zone. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the silicon carbide powder synthesis method provided in Embodiment 1. Figure 2 This is a schematic diagram of the silicon carbide powder synthesis apparatus provided in Embodiment 2 from a first-view perspective. Figure 3 This is a schematic diagram of the condenser plate in the silicon carbide powder synthesis apparatus provided in this embodiment 2 from a second perspective. Figure 4 This is a partial structural diagram of the flow guide in the silicon carbide powder synthesis apparatus provided in Embodiment 2. Figure 5 This is a schematic diagram of the silicon carbide powder synthesis apparatus provided in Embodiment 3 from a first-view perspective.

[0018] Icons: 100 - Crucible; 110 - Crucible body; 111 - Reaction zone; 1111 - Synthesis raw materials; 112 - Recovery zone; 120 - Crucible lid; 200 - Heating element; 300-Condensing plate; 310-Plate body; 320-Cooling channel; 321-Main cooling channel; 322-Branch cooling channel; 330-Gas collection slot; 340-Medium inlet pipe; 350-Medium outlet pipe; 360-Guide component; 361-Guide surface; 362-Sharp part; 400-Insulation Board; 500-Collection tube. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention 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 invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] Silicon carbide powder refers to a powdery material composed of a large number of tiny silicon carbide crystal particles, and it is an upstream raw material for silicon carbide products.

[0026] In the synthesis of silicon carbide powder, carbon powder and silicon powder are typically mixed. The mixed or pressed raw materials are placed in a high-temperature furnace, where the silicon powder and carbon powder mixture is heated to 2000℃-2300℃ to react and synthesize silicon carbide crystal particles. When the temperature exceeds 1800℃, the silicon powder undergoes vigorous sublimation to form gaseous silicon. The gaseous silicon atoms in the gaseous silicon react with the solid carbon powder to form silicon carbide. Simultaneously, the gaseous silicon diffuses into the pores of the carbon powder particles, reacting internally to form silicon carbide. However, some of the gaseous silicon escapes from the reaction zone, resulting in silicon loss.

[0027] The following detailed description, through examples and in conjunction with the accompanying drawings, details the steps, implementation principles, and technical effects of the silicon carbide powder synthesis method provided by the present invention, as well as the overall structure, working principle, and technical effects of the supporting silicon carbide powder synthesis apparatus.

[0028] Example 1: This embodiment provides a method for synthesizing silicon carbide powder, which can simultaneously recover the gaseous silicon escaping from the reaction zone 111 in situ, achieving high silicon source recovery efficiency. Please see Figure 1 This embodiment provides a method for synthesizing silicon carbide powder, which includes the following steps: S1. The synthetic raw material 1111 is placed in the crucible 100. The synthetic raw material 1111 includes carbon powder and silicon powder.

[0029] In this embodiment, the crucible 100 is used to provide space for the synthesis of silicon carbide powder and the subsequent recovery of silicon source; carbon powder and silicon powder are used to provide the carbon source and silicon source required for silicon carbide synthesis, respectively.

[0030] S2. Heat the crucible 100 to sublimate the silicon powder and form fumed silicon; a portion of the fumed silicon reacts with the carbon powder to form silicon carbide, while the other portion of the fumed silicon volatilizes and dissipates.

[0031] In this embodiment, in order to sublimate the silicon powder and react with the carbon powder to form silicon carbide, the crucible needs to be heated to 100 to 2000℃-2300℃. When the temperature reaches above 1800℃, the silicon powder will sublimate violently and form gaseous silicon. At this time, part of the gaseous silicon reacts with the carbon powder in the reaction zone 111 to form silicon carbide, and another part of the gaseous silicon volatilizes and escapes. The volatilized and escaped part of the gaseous silicon is the silicon loss part.

[0032] S3. Recover the escaped fumed silicon and allow it to participate in the reaction again to form silicon carbide until the silicon carbide powder synthesis process is completed.

[0033] Furthermore, the method for recovering the fumed silicon escaping from reaction zone 111 is as follows: The gaseous silicon escaping from the reaction zone 111 is liquefied in the recovery zone 112 to form liquid silicon. The liquid silicon is then recovered to the reaction zone 111 under gravity to participate in the reaction again and form silicon carbide.

[0034] In some embodiments, a portion of the recovery zone 112 may be at a relatively low temperature (e.g., 1200°C-1400°C) so that fumed silicon can liquefy in the zone and form liquid silicon. The liquid silicon continuously condenses and is eventually recovered to the reaction zone 111 under gravity and participates in the reaction again. This cycle continues until the silicon carbide powder synthesis process is completed.

[0035] This embodiment provides a method for synthesizing silicon carbide powder. The raw materials are placed in a crucible 100, and a heating element 200 heats the crucible 100, causing the silicon powder to sublimate and form fumed silicon. A portion of the fumed silicon reacts with the carbon powder in the reaction zone 111 to form silicon carbide, while another portion escapes from the reaction zone 111 and enters a recovery zone 112. By recovering the fumed silicon that enters the recovery zone 112, the escaped fumed silicon participates in the reaction again to form silicon carbide until the silicon carbide powder synthesis process is completed. This invention enables in-situ recovery of the fumed silicon that escapes into the recovery zone 112, exhibiting high silicon source recovery efficiency.

[0036] Example 2: This embodiment provides a silicon carbide powder synthesis apparatus for synthesizing silicon carbide powder, and is capable of in-situ recovery of volatilized silicon to reduce silicon loss caused by volatilization.

[0037] Please see Figure 2 This embodiment provides a silicon carbide powder synthesis apparatus, including a crucible 100, a heating element 200 arranged around the crucible 100, and a condenser plate 300 disposed inside the crucible 100; wherein, the crucible 100 includes a crucible body 110 and a crucible cover 120 covering the crucible body 110, the crucible body 110 and the crucible cover 120 together define a connected reaction zone 111 and a recovery zone 112; wherein, the reaction zone 111 contains synthesis raw materials 1111, the synthesis raw materials 1111 including solid carbon powder and silicon powder; the condenser plate 300 is disposed in the recovery zone 112.

[0038] During the synthesis of silicon carbide powder, the heating element 200 can heat the crucible 100, so that the synthesis raw material 1111 in the crucible 100 is heated to 2000℃-2300℃. When the temperature reaches above 1800℃, the silicon powder will sublimate violently and form gaseous silicon. At this time, part of the gaseous silicon reacts with the carbon powder in the reaction zone 111 to form silicon carbide, and another part of the gaseous silicon escapes from the reaction zone 111 and volatilizes to the recovery zone 112. The gaseous silicon entering the recovery zone 112 can contact the condenser plate 300. After contacting the condenser plate 300, the gaseous silicon is cooled and liquefied to form liquid silicon. The liquid silicon continuously accumulates on the condenser plate 300 and is eventually recovered to the reaction zone 111 under the action of gravity to react with the carbon powder again to form silicon carbide. This cycle continues until the silicon carbide powder synthesis process ends.

[0039] The silicon carbide powder synthesis apparatus provided in this embodiment has a condenser plate 300 installed in the crucible 100. This allows the volatilized silicon during the synthesis process to liquefy under the action of the condenser plate 300 to form liquid silicon. The liquid silicon continuously accumulates and is eventually recovered to the reaction zone 111 under gravity to react with the carbon powder again and form silicon carbide. This completes the in-situ recovery of the volatilized silicon, reducing silicon loss while achieving high recovery efficiency.

[0040] Please continue reading. Figure 1 In this embodiment, the condenser plate 300 can be fixed on the side of the crucible cover 120 near the synthetic raw material 1111. The condenser plate 300 is used to cool the fumed silicon and cause the fumed silicon to liquefy when it comes into contact with the condenser plate 300.

[0041] Understandably, the temperature of the condenser plate 300 is determined by the ability to liquefy the vaporized silicon, and no specific limit is imposed here.

[0042] In some embodiments, the temperature of the condenser plate 300 should be less than 1414°C so that the fumed silicon liquefies upon contact with the condenser plate 300.

[0043] For example, the temperature of the condenser plate 300 can be 1400℃, 1200℃, 1000℃, etc.

[0044] Preferably, the temperature of the condenser plate 300 is 1200℃.

[0045] Please see Figure 3 Furthermore, the condenser plate 300 includes a plate body 310, a cooling channel 320 formed on the plate body 310, and an air collecting groove 330 arranged around the plate body 310; a cooling medium is introduced into the cooling channel 320, and the cooling channel 320 has a corresponding input end and an output end; wherein, the input end of the cooling channel 320 is connected to a medium input pipe 340, the output end of the cooling channel 320 is connected to the air collecting groove 330, and the air collecting groove 330 is connected to a medium output pipe 350.

[0046] Understandably, the condenser plate 300 will heat up under the action of the crucible 100 and the heating element 200. In order to keep the condenser plate 300 at a relatively low temperature so that the fumed silicon liquefies upon contact with the condenser plate 300, in this embodiment, a cooling channel 320 is provided on the condenser plate 300. A cooling medium flows through the cooling channel 320, which can remove some of the heat from the condenser plate 300 to control its temperature. The cooling channel 320 has a corresponding input end and an output end. The input end can be directly or indirectly connected to the medium input pipe 340, and the output end can be directly or indirectly connected to the medium output pipe 350, so that the cooling medium can be input into the cooling channel 320 through the medium input pipe 340 and the input end, and output out of the cooling channel 320 through the output end and the medium output pipe 350.

[0047] In some embodiments, the cooling channel 320 includes multiple output ends with different output directions. To facilitate the connection of the multiple output ends to the medium output pipe 350, the condenser plate 300 also includes a gas collecting groove 330 surrounding the plate body 310. The multiple output ends can be connected to the gas collecting groove 330 respectively. The cooling medium is collected in the gas collecting groove 330 and finally output through the medium output pipe 350, such as... Figure 3 As shown, Figure 3 The arrows inside the central air collection tank 330 indicate the flow direction of the cooling medium.

[0048] It should be noted that, in order to avoid the condenser plate 300 disrupting the temperature field, the condenser plate 300 should be kept at a specific distance from the synthetic raw material 1111. In actual operation, the distance between the condenser plate 300 and the synthetic raw material 1111 is related to the height of the packing and the size of the crucible 100. Operators can make adaptive adjustments according to actual work needs, and no limitation is made here.

[0049] Please continue reading. Figure 3 Furthermore, the cooling channel 320 includes multiple main cooling channels 321, one end of which is connected to the medium input pipe 340, and the other end of each main cooling channel 321 is connected to multiple branch cooling channels 322. The end of the branch cooling channel 322 away from the main cooling channel 321 is connected to the air collection groove 330.

[0050] In order to ensure that the cooling channels 320 can act evenly and fully on the condenser plate 300, in this embodiment, multiple main cooling channels 321 and branch cooling channels 322 are arranged radially to cover the condenser plate 300 as much as possible and increase the heat exchange area.

[0051] In other embodiments, the main cooling channel 321 and the branch cooling channel 322 may have various opening methods, such as serpentine bends or "U" shaped openings, as long as they can act evenly and fully on the condenser plate 300, and are not limited here.

[0052] Please continue reading. Figure 2 Since the condensing plate 300 is disposed on the crucible lid 120, in order to avoid mutual interference between the condensing plate 300 and the crucible lid 120 in terms of heat transfer, in this embodiment, a heat insulation plate 400 is also disposed between the condensing plate 300 and the crucible lid 120. The heat insulation plate 400 is intended to reduce the temperature exchange between the condensing plate 300 and the crucible lid 120.

[0053] Vaporized silicon can be liquefied on the condenser plate 300 to form liquid silicon. Liquid silicon can accumulate on the surface of the condenser plate 300. In order to avoid the liquid silicon staying on the condenser plate 300 for too long, in this embodiment, multiple flow guides 360 are arranged in an array on the side surface of the condenser plate 300 near the synthetic raw material 1111.

[0054] In actual operation, the flow guide 360 ​​is in direct contact with the condenser plate 300. The temperature of the flow guide 360 ​​can be reduced under the action of the condenser plate 300, so that the gaseous silicon liquefies when it comes into contact with the flow guide 360. The liquefied liquid silicon can drip into the reaction zone 111 under the guidance of the flow guide 360 ​​and gravity. The liquid silicon dripping into the reaction zone 111 participates in the reaction again and forms silicon carbide.

[0055] Please see Figure 4 Furthermore, the flow guide 360 ​​includes a flow guide surface 361 and at least one sharp portion 362; in some embodiments, the flow guide 360 ​​may be an inverted conical structure or a pyramidal structure.

[0056] In actual operation, since the temperature of the guide component 360 can be reduced by the action of the condenser plate 300, the gaseous silicon can liquefy to form liquid silicon when it comes into contact with the guide surface 361. The liquid silicon adheres to the guide surface 361 and gathers at the tip 362 under the action of gravity, forming a water droplet. The water droplet-shaped liquid silicon is easily suspended in the air at the tip 362 and exceeds the range of the support point. The gravitational torque of the water droplet-shaped liquid silicon at the tip 362 is more likely to overcome the surface tension and adsorb it onto the solid, thereby guiding the liquid silicon to drip more easily into the reaction zone 111 under the action of gravity.

[0057] This embodiment provides a silicon carbide powder synthesis apparatus, and the silicon carbide powder synthesis process is as follows: The synthetic raw material 1111, composed of carbon powder and silicon powder, is heated to 2000℃-2300℃ under the heating action of the heating element 200. When the temperature reaches above 1800℃, the silicon powder will sublimate violently and form gaseous silicon. At this time, part of the gaseous silicon reacts with the carbon powder in the reaction zone 111 to form silicon carbide, and another part of the gaseous silicon escapes from the reaction zone 111 and volatilizes to the recovery zone 112. At this time, the guide element 360 has a low surface temperature because it is in direct contact with the condenser plate 300. The gaseous silicon entering the recovery zone 112 can contact multiple guide elements 360 and liquefy on the guide surface 361 of multiple guide elements 360 to form liquid silicon. The liquid silicon will adhere to and accumulate on the guide surface 361. Under the action of gravity, the liquid silicon gathers at the sharp part 362 and forms a water droplet. Finally, under the action of gravity, it drips into the reaction zone 111, completing the recovery of the volatilized gaseous silicon. This embodiment achieves high silicon source recovery efficiency by in-situ recovering the gaseous silicon that has escaped into the recovery zone 112.

[0058] Example 3: Please see Figure 5 This embodiment also provides a silicon carbide powder synthesis device, which is largely the same as Embodiment 2 in terms of working principle and technical effects, with the difference being: In this embodiment, the reaction zone 111 is arrayed with a plurality of collection tubes 500 that correspond to the flow guide 360 ​​and are open at both ends. The correspondence here means that the apex of the sharp part 362 in the flow guide 360 ​​is on the axis of the corresponding collection tube 500, so that the liquid silicon dripping from the corresponding sharp part 362 can drip directly into the collection tube 500 and be collected by the collection tube 500.

[0059] Furthermore, one end of the collection pipe 500 away from the guide member 360 is buried in the synthetic raw material 1111, and the other end of the collection pipe 500 extends towards the recovery area 112.

[0060] Please continue reading. Figure 5 , Figure 5 The direction of the middle arrow indicates the dripping path of the liquid silicon. Compared with Example 2, in this example, the dripping liquid silicon can directly enter the middle of the synthesis raw material 1111 instead of dripping onto the surface of the synthesis raw material 1111. The difference is that the liquid silicon dripping onto the surface of the synthesis raw material 1111 will rapidly vaporize at high temperature and escape from the reaction zone 111 again. However, the liquid silicon entering through the collection pipe 500 can directly reach the middle of the synthesis raw material 1111. At this time, when the liquid silicon vaporizes, it can react with the surrounding carbon powder again, further improving the recovery efficiency.

[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for synthesizing silicon carbide powder, characterized in that, include: The synthetic raw material (1111) is placed in a crucible (100), and the synthetic raw material (1111) includes carbon powder and silicon powder; The crucible (100) is heated so that the silicon powder sublimates and forms gaseous silicon; a portion of the gaseous silicon reacts with the carbon powder to form silicon carbide, and another portion of the gaseous silicon volatilizes and dissipates. The escaped fumed silicon is recovered and allowed to participate in the reaction again to form silicon carbide until the silicon carbide powder synthesis process is completed.

2. The method for synthesizing silicon carbide powder according to claim 1, characterized in that, The method for recovering the escaped fumed silicon is as follows: The escaped gaseous silicon is liquefied to form liquid silicon, which is then recovered under gravity and participates in the reaction again to form silicon carbide.

3. A silicon carbide powder synthesis apparatus, characterized in that, include: A crucible (100) includes a crucible body (110) and a crucible lid (120) covering the crucible body (110). The crucible body (110) and the crucible lid (120) together define a connected reaction zone (111) and a recovery zone (112). The reaction zone (111) contains a synthesis raw material (1111), which includes solid carbon powder and silicon powder. A heating element (200) is arranged around the outside of the crucible body (110), and silicon powder sublimates and forms gaseous silicon under the action of the heating element (200); A condenser plate (300) is disposed in the recovery zone (112). Under the action of the condenser plate (300), the gaseous silicon is liquefied and forms liquid silicon in the recovery zone (112). The liquid silicon is recovered to the reaction zone (111) under the action of gravity.

4. The silicon carbide powder synthesis apparatus according to claim 3, characterized in that, The condensing plate (300) is disposed on the crucible cover (120). The condensing plate (300) includes a plate body (310), a cooling channel (320) formed on the plate body (310), and a gas collecting groove (330) disposed around the plate body (310). Cooling medium is introduced into the cooling channel (320), and the cooling channel (320) has a corresponding input end and output end; wherein, the input end of the cooling channel (320) is connected to a medium input pipe (340), the output end of the cooling channel (320) is connected to the gas collecting groove (330), and the gas collecting groove (330) is connected to a medium output pipe (350).

5. The silicon carbide powder synthesis apparatus according to claim 4, characterized in that, The cooling channel (320) includes multiple main cooling channels (321), one end of each main cooling channel (321) is connected to the medium input pipe (340), and the other end of each main cooling channel (321) is connected to multiple branch cooling channels (322). The end of each branch cooling channel (322) away from the main cooling channel (321) is connected to the gas collection groove (330).

6. The silicon carbide powder synthesis apparatus according to claim 5, characterized in that, The multiple main cooling channels (321) and branch cooling channels (322) are arranged radially.

7. The silicon carbide powder synthesis apparatus according to claim 4, characterized in that, A heat insulation plate (400) is provided between the condenser plate (300) and the crucible lid (120).

8. The silicon carbide powder synthesis apparatus according to claim 3, characterized in that, The condenser plate (300) has multiple flow guides (360) arranged in an array on the side surface near the synthetic raw material (1111). The flow guide (360) includes a flow guide surface (361) and at least one sharp part (362). Vaporized silicon can be liquefied on the flow guide surface (361) to form liquid silicon. Liquid silicon can accumulate at the sharp part (362) and be recycled to the reaction zone (111) under the action of gravity.

9. The silicon carbide powder synthesis apparatus according to claim 8, characterized in that, The guide element (360) is conical or pyramidal in shape.

10. The silicon carbide powder synthesis apparatus according to claim 8, characterized in that, The reaction zone (111) is provided with an array of multiple collection tubes (500) with openings at both ends, and the multiple collection tubes (500) are correspondingly arranged with the multiple flow guides (360); One end of the collection tube (500) is embedded in the synthetic raw material (1111), and the other end of the collection tube (500) extends toward the recycling area (112).

Images