Equipment for preparing SiC from methylsilane

Abstract

The invention relates to equipment for preparing SiC from methylsilane. The equipment comprises a mixing tank, a CVD furnace, a vacuum pump, a circulating cooling water tank, a condensation recovery device and a particle filter, and the particle filter is arranged between pipelines between the CVD furnace and the vacuum pump; the particle filtering device comprises a filtering assembly and a negative pressure cleaning assembly; the condensation recovery device is used for cooling and recovering methylsilane which is not generated by reaction and byproducts generated by reaction in the CVD furnace, and dust-entrained particles are filtered by the particle filtering device and then pumped out by the vacuum pump, so that the deposition of methylsilane residues in a reaction chamber and a pipeline is avoided, and the risk of combustion explosion is reduced; the servo motor is used for driving the cleaning brush to sweep the particle filter screen on one hand and adjusting the working states of the working parts at the left end and the right end of the feeding pipe on the other hand, so that the continuity of dust particle filtering is ensured, the particle filter screen is swept alternately, and dust is prevented from entering the vacuum pump.

Description

Technical Field

[0001] This invention belongs to the field of special materials manufacturing technology, specifically relating to an apparatus for preparing SiC from methylsilane. Background Technology

[0002] SiC coatings are a type of high-temperature resistant ceramic with a tetragonal crystal structure and a high melting temperature (above 2700 degrees Celsius). Among the many methods for preparing SiC materials, CVD (Silicon Carbide Dioxide) technology has excellent adaptability to parts with complex shapes and internal surfaces. It can achieve near-scale forming of large-sized, thin-walled, and complex components, and can be prepared at relatively low temperatures (700-1200 degrees Celsius), avoiding damage to the material structure caused by high-temperature treatment. It can also easily control the composition and fine structure of the coating, which is beneficial for controlling the structural or compositional gradient at the coating / substrate interface. It is considered the most promising method for preparing silicon carbide coatings. Silicon carbide crystals prepared by CVD technology have a dense structure, orderly lattice arrangement, tight bonding with the substrate material, and are characterized by high temperature resistance, wear resistance, chemical corrosion resistance, and good thermal conductivity.

[0003] Currently, the reaction chamber of a CVD furnace is directly connected to the vacuum pump. After a SiC coating deposition, some methylsilane often remains in the reaction chamber and pipes. Methylsilane is a substance with a risk of combustion and explosion. Therefore, after a certain number of depositions, the pipes need to be cleaned frequently to avoid the risk of explosion. At the same time, the deposition will cause some dust to enter the vacuum pump and contaminate the vacuum pump oil. Therefore, the vacuum pump also needs to be cleaned frequently. As a result, frequent cleaning work during the production process will increase the labor intensity of workers and increase costs accordingly.

[0004] By adding a condensation recovery device at the bottom of the CVD furnace, unreacted methylsilane and byproducts are condensed and recovered. In addition, a particulate filter is installed at the pump inlet of the vacuum pump to intercept SiC deposited dust. The particulate filter is cleaned by wind power and transmission mechanism, which can effectively prevent methylsilane from remaining in the reaction chamber and pipelines, reduce the risk of combustion and explosion, and improve the safety of the production process.

[0005] Therefore, it is essential to install a condensation recovery device at the bottom of the CVD furnace and a particulate filter at the pump inlet of the vacuum pump. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide an apparatus for preparing SiC from methylsilane to solve the above problems.

[0007] To achieve the above objectives, the technical solution adopted by this invention is as follows: An apparatus for preparing SiC from methylsilane, comprising a mixing tank, a CVD furnace, a vacuum pump, a circulating cooling water tank, a condensation recovery device, and a particulate filter. The outlet of the mixing tank is connected to the inlet of the CVD furnace via a pipeline. The circulating cooling water tank is connected to the CVD furnace via a cooling water pipe. The exhaust gas outlet at the bottom of the CVD furnace is connected to the condensation recovery device via a pipeline. The CVD furnace and the vacuum pump are connected via a pipeline. The particulate filter is installed in the pipeline between the CVD furnace and the vacuum pump. The particulate filter includes a filter assembly and a negative pressure cleaning assembly. The filter assembly includes a feed pipe, two discharge boxes symmetrically distributed on both sides of the feed pipe, two filter boxes, and two dust emission boxes. The feed pipe, discharge boxes, filter boxes, and dust emission boxes are connected in sequence. A servo motor is fixed at the end of the right dust emission box, and a sealing baffle is fixed at the end of the left dust emission box. The negative pressure cleaning assembly includes an upper end cover, a diversion box, a negative pressure pipe, and a spray pipe connected in sequence via flanges. The spray pipe has a diffuser-shaped structure with a small diameter at the upper end and a large diameter at the lower end. A converging spray pipe is installed inside the negative pressure pipe. The upper edge of the spray pipe is fixed between the lower end face of the diversion box and the upper end face of the negative pressure pipe.

[0008] The feed pipe is a horizontally placed cylindrical structure. A first feed port is provided on the upper side of the feed pipe. The first feed port is connected to the CVD furnace through a pipeline. A first partition is fixed inside the feed pipe near the left and right ports. An opening is provided in the middle of the first partition to facilitate the passage of the servo motor output shaft. Multiple through holes are evenly distributed around the central opening on the first partition.

[0009] The discharge box consists of two parts: a first inner tube and a first outer ring box. The first outer ring box is a circular box structure surrounding the first inner tube. Multiple through holes leading to the first outer ring box are evenly distributed on the top end face of the discharge box. A first discharge port is provided on the lower side of the first outer ring box. A first adjusting turntable is provided in the groove formed between the bottom end of the discharge box and the first partition. The first adjusting turntable is fixedly connected to the output shaft of the servo motor. Through holes corresponding to the through holes on the first partition are evenly distributed on the first adjusting turntable. When the servo motor drives the first adjusting turntable to rotate and the through holes on the first adjusting turntable coincide with the through holes on the first partition, the feed pipe is connected to the middle pipe of the discharge box.

[0010] The filter box contains a fixed particle filter screen, which divides the filter box into a second inner tube and a second outer ring box. The second inner tube is connected to the first inner tube of the discharge box. Multiple through holes leading to the second outer ring box are evenly distributed on the bottom end face of the filter box, each corresponding to a through hole on the top of the discharge box. An adjusting ring is installed in the groove between the bottom end face of the filter box and the top end face of the discharge box. The inner side of the adjusting ring is fixedly connected to the output shaft of the servo motor via multiple evenly distributed first connecting rods. The adjusting ring has through holes corresponding to the through holes at the bottom of the filter box and the top of the discharge box. When the servo motor drives the adjusting ring to rotate until its through holes align with the through holes of the filter box and the discharge box, the second outer ring box is connected to the first outer ring box of the discharge box. Multiple cleaning brushes are evenly distributed around the output shaft of the servo motor on the inner side of the particle filter screen. The front of the cleaning brush is in contact with the surface of the particle filter screen, and the back is fixedly connected to the output shaft of the servo motor via second connecting rods. The two ends of the second connecting rods are fixed to the back of the cleaning brushes and the output shaft, respectively.

[0011] The dust emission box is a cylindrical structure with an opening at the left end, and a second discharge port is provided on the lower side of the dust emission box. A second partition is provided near the opening at the left end of the dust emission box. Both the second partition and the middle of the dust emission box are provided with openings to facilitate the passage of the output shaft of the servo motor. Multiple through holes are evenly distributed around the middle opening on the second partition. A second adjusting turntable is provided in the groove formed between the second partition and the top end face of the filter box. The second adjusting turntable is fixedly connected to the output shaft of the servo motor. The second adjusting turntable has through holes evenly distributed on it, corresponding to the through holes on the second partition. When the servo motor drives the second adjusting turntable to rotate and the through holes on the second adjusting turntable coincide with the through holes on the second partition, the second inner pipe is connected to the dust emission box.

[0012] Two third partitions are fixed in the middle of the distribution box, dividing it into an upper cavity, a middle cavity, and a lower cavity. A through hole is provided in the middle of the third partition. A third discharge port is provided on the front side of the upper and middle cavities, connected to a pipeline leading to the vacuum pump. A second inlet is provided on the side of the middle cavity, connected to the first discharge port via a pipeline. Adjustable plugs are provided in both the upper and lower cavities. The adjusting plugs near the third partitions are truncated cone-shaped structures, smaller at the top and larger at the bottom. By adjusting the distance between the adjusting plug and the third partition, the gap between the truncated cone-shaped structure of the adjusting plug and the through hole in the middle of the third partition is adjusted. Multiple pads are evenly distributed on the bottom edge of the adjusting plug to prevent it from completely blocking the through hole in the middle of the third partition. An adjusting spring is provided on the back side of each adjusting plug.

[0013] The converging nozzle is larger at the top and smaller at the bottom, and a limit panel is provided at the upper port of the converging nozzle. Multiple third connecting rods are evenly distributed between the side edge of the limit panel and the inner side wall of the upper end of the converging nozzle. One end of the third connecting rod is fixedly connected to the converging nozzle, and the other end of the third connecting rod is fixedly connected to the side edge of the limit panel. The lower end of the adjusting spring located in the lower cavity is fixedly connected to the limit panel, and the upper end of the adjusting spring is fixedly connected to the adjusting plug located in the lower cavity.

[0014] An adjusting screw is threadedly connected to the middle of the upper end cover. A knob is fixed to one end of the adjusting screw that protrudes from the upper end cover. An adjusting panel is rotatably sleeved at the lower end of the adjusting screw. The upper end of the adjusting spring located in the upper cavity is fixedly connected to the adjusting panel, and the lower end of the adjusting spring is fixedly connected to the adjusting plug located in the upper cavity.

[0015] The beneficial effects of this invention are as follows: This invention utilizes a condensation recovery device to cool and recover unreacted methylsilane and byproducts generated during the CVD furnace. Dust particles are filtered by a particle filter and then extracted by a vacuum pump, preventing methylsilane residue from accumulating in the reaction chamber and pipes, thus reducing the risk of combustion and explosion. When the servo motor is activated, it drives a cleaning brush to clean the particle filter screen. Simultaneously, the servo motor drives the first adjusting turntable, adjusting ring, and second adjusting turntable to rotate, adjusting the working states of the working components at both ends of the feed pipe. This allows the feed pipe to alternate between dust particle filtration and dust particle cleaning. Airflow enters the lower chamber, and the pressure change caused by the flow rate change through the converging nozzle creates negative pressure in the negative pressure pipe, enabling the working components at both ends of the feed pipe to alternately filter dust particles and clean the particle filter screen. This ensures continuous dust particle filtration, alternately cleans the particle filter screen, and recovers the cleaned dust particles into the condensation recovery device, preventing dust from entering the vacuum pump. Attached Figure Description

[0016] Figure 1 Structural diagram of the equipment for preparing SiC from methylsilane;

[0017] Figure 2 This is a structural diagram of a particulate filter;

[0018] Figure 3 This is a diagram of the internal structure of a particulate filter;

[0019] Figure 4 This is a diagram of the internal structure of the feed pipe;

[0020] Figure 5 This is a diagram of the internal structure of the discharge box;

[0021] Figure 6 This is a diagram of the internal structure of the filter box;

[0022] Figure 7 This is a structural diagram of a dust emission box;

[0023] Figure 8 Diagram of the internal structure of the negative pressure cleaning component;

[0024] Figure 9 This is a diagram of the internal structure of the manifold;

[0025] Figure 10 This is a diagram of the internal structure of a converging nozzle.

[0026] Figure 11 This is a diagram of the internal structure of the upper end cap;

[0027] Numbered in the diagram: 1 Mixing tank; 2 CVD furnace; 3 Vacuum pump; 4 Circulating cooling water tank; 5 Condensation recovery device; 6 Particle filter; 7 Filter assembly; 8 Negative pressure cleaning assembly; 9 Feed pipe; 901 First feed inlet; 10 Discharge box; 1001 First inner pipe; 1002 First outer ring box; 1003 First discharge port; 11 Filter box; 1101 Second inner pipe; 1102 Second outer ring box; 12 Dust emission box; 1201 Second discharge port; 13 Servo motor; 14 Sealing baffle; 15 First partition; 16 First adjusting turntable; 17 Particle filter Filter screen; 18 Adjusting ring; 19 First connecting rod; 20 Cleaning brush; 21 Second connecting rod; 22 Second partition; 23 Second adjusting turntable; 24 Upper end cover; 25 Diverter box; 2501 Upper cavity; 2502 Middle cavity; 2503 Lower cavity; 2504 Third discharge port; 2505 Second inlet; 26 Negative pressure pipe; 27 Spray pipe; 28 Converging spray pipe; 2801 Limiting panel; 29 Third partition; 30 Adjusting plug; 3001 Pad; 31 Adjusting spring; 32 Third connecting rod; 33 Adjusting screw; 3301 Knob; 34 Adjusting panel. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0029] like Figure 1-11As shown, an apparatus for preparing SiC from methylsilane includes a mixing tank 1, a CVD furnace 2, a vacuum pump 3, a circulating cooling water tank 4, a condensation recovery device 5, and a particle filter 6. The outlet of the mixing tank 1 is connected to the inlet of the CVD furnace 2 via a pipeline, and the mixing tank 1 supplies material to the CVD furnace via a pipeline. The circulating cooling water tank 4 is connected to the CVD furnace 2 via a cooling water pipe, and the circulating cooling water tank 4 supplies cooling water to the cooling water pipe to cool the CVD furnace 2. The exhaust outlet at the bottom of the CVD furnace 2 is connected to the condensation recovery device 5 via a pipeline, and the CVD furnace 2 is connected to the vacuum pump 3 via a pipeline. The particle filter 6 is located between the pipelines of the CVD furnace 2 and the vacuum pump 3. The particle filter 6 includes a filter assembly 7 and a negative pressure cleaning assembly 8. 7 includes a feed pipe 9, two discharge boxes 10, two filter boxes 11, and two dust emission boxes 12. The discharge boxes 10, filter boxes 11, and dust emission boxes 12 are symmetrically distributed on both sides of the feed pipe 9, and the feed pipe 9, discharge boxes 10, filter boxes 11, and dust emission boxes 12 are connected in sequence by flanges. A servo motor 13 is fixed at the end of the dust emission box 12 on the right side, and a sealing baffle 14 is fixed at the end of the dust emission box 12 on the left side. The negative pressure cleaning component 8 includes an upper end cover 24, a diversion box 25, a negative pressure pipe 26, and a spray pipe 27. The upper end cover 24, diversion box 25, negative pressure pipe 26, and spray pipe 27 are connected in sequence by flanges. A converging spray pipe 28 is provided inside the negative pressure pipe 26, and the upper edge of the converging spray pipe 28 is fixed between the lower end face of the diversion box 25 and the upper end face of the negative pressure pipe 26.

[0030] In this embodiment, the feed pipe 9 is a horizontally placed cylindrical structure. A first feed port 901 is provided on the upper side of the feed pipe 9. The first feed port 901 is connected to the CVD furnace 2 through a pipeline. A first partition plate 15 is fixed inside the feed pipe 9 near the left and right ports. An opening is provided in the middle of the first partition plate 15 to facilitate the passage of the output shaft of the servo motor 13. Multiple through holes are evenly distributed around the middle opening on the first partition plate 15.

[0031] In this embodiment, the discharge box 10 is composed of two parts: a first inner tube 1001 and a first outer ring box 1002. The first outer ring box 1002 is a circular box structure surrounding the first inner tube 1001. The top end face of the discharge box 10 has a plurality of through holes evenly distributed to the first outer ring box 1002. The lower side of the first outer ring box 1002 is provided with a first discharge port 1003. The first adjusting turntable 16 is provided in the groove formed between the bottom end of the discharge box 10 and the first partition 15. The first adjusting turntable 16 is fixedly connected to the output shaft of the servo motor 13. The first adjusting turntable 16 has through holes evenly distributed on it, corresponding to the through holes on the first partition 15. When the servo motor 13 drives the first adjusting turntable 16 to rotate and the through holes on the first adjusting turntable 16 coincide with the through holes on the first partition 15, the feed pipe 9 is connected to the middle pipe of the discharge box 10.

[0032] In this embodiment, a particle filter screen 17 is fixed inside the filter box 11, dividing the filter box 11 into two parts: a second inner pipe 1101 and a second outer ring box 1102. The second inner pipe 1101 is connected to the first inner pipe 1001. Multiple through holes leading to the second outer ring box 1102 are evenly distributed on the bottom end face of the filter box 11, and these through holes correspond one-to-one with the through holes at the top of the discharge box 10. An adjusting ring 18 is installed in the groove formed between the bottom end face of the filter box 11 and the top end face of the discharge box 10. Multiple first connecting rods 19 are evenly distributed between the inner side of the adjusting ring 18 and the output shaft of the servo motor 13. One end of each first connecting rod 19 is fixedly connected to the inner side of the adjusting ring 18, and the other end is connected to the servo motor 13. The output shaft is fixedly connected. The adjusting ring 18 has multiple through holes evenly distributed on it, corresponding to the through holes at the bottom of the filter box 11. When the servo motor 13 drives the adjusting ring 18 to rotate and the through holes on the adjusting ring 18 are connected to the through holes at the top of the discharge box 10 and the bottom of the filter box 11, the second outer ring box 1102 is connected to the first outer ring box 1001. Multiple cleaning brushes 20 are evenly distributed around the output shaft of the servo motor 13 on the inner side of the particle filter screen 17. The front of the cleaning brushes 20 contacts the particle filter screen 17 and is used to clean the particle filter screen 17. A second connecting rod 21 is fixed between the back of the cleaning brushes 20 and the output shaft of the servo motor 13. One end of the second connecting rod 21 is fixedly connected to the back of the cleaning brushes 20, and the other end of the second connecting rod 21 is fixedly connected to the output shaft of the servo motor 13.

[0033] In this embodiment, the dust emission box 12 is a cylindrical structure with an opening at the left end, and a second discharge port 1201 is provided on the lower side of the dust emission box 12. A second partition 22 is provided near the opening at the left end of the dust emission box 12. Both the second partition 22 and the dust emission box 12 have openings in the middle to facilitate the passage of the output shaft of the servo motor 13. Multiple through holes are evenly distributed around the middle opening on the second partition 22. A second adjusting turntable 23 is provided in the groove formed between the second partition 22 and the top end face of the filter box 11. The second adjusting turntable 23 is fixedly connected to the output shaft of the servo motor 13. The second adjusting turntable 23 has through holes evenly distributed on it, corresponding to the through holes on the second partition 22. When the servo motor 13 drives the second adjusting turntable 23 to rotate and the through holes on the second adjusting turntable 23 coincide with the through holes on the second partition 22, the second inner pipe 1101 is connected to the dust emission box 12.

[0034] In this embodiment, two third partitions 29 are fixed in the middle of the distribution box 25, dividing the distribution box 25 into three parts: an upper cavity 2501, a middle cavity 2502, and a lower cavity 2503. A through hole is provided in the middle of the third partition 29. A third discharge port 2504 is provided on the front side of the upper cavity 2501, and the third discharge port 2504 is connected to a pipeline leading to the vacuum pump. A second inlet 2505 is provided on the side of the middle cavity 2502, and the second inlet 2505 is connected to the first discharge port 1003 through a pipeline. The upper cavity 2501... Both 501 and the lower cavity 2503 are equipped with adjusting plugs 30. The adjusting plug 30 is a frustum-shaped structure with a small top and a large bottom on the side near the third partition 29. By adjusting the distance between the adjusting plug 30 and the third partition 29, the size of the gap between the frustum-shaped structure of the adjusting plug 30 and the through hole in the middle of the third partition 29 can be adjusted. Multiple pads 3001 are evenly distributed on the bottom edge of the adjusting plug 30 to prevent the adjusting plug 30 from completely blocking the through hole in the middle of the third partition 29. Each adjusting plug 30 is equipped with an adjusting spring 31 on its back side.

[0035] In this embodiment, the converging nozzle 28 is larger at the top and smaller at the bottom, and a limiting panel 2801 is provided at the upper port of the converging nozzle 28. Multiple third connecting rods 32 are evenly distributed between the side edge of the limiting panel 2801 and the inner side wall of the upper end of the converging nozzle 28. One end of the third connecting rod 32 is fixedly connected to the converging nozzle 28, and the other end of the third connecting rod 32 is fixedly connected to the side edge of the limiting panel 2801. The lower end of the adjusting spring 31 located in the lower cavity 2503 is fixedly connected to the limiting panel 2801, and the upper end of the adjusting spring 31 is fixedly connected to the adjusting plug 30 located in the lower cavity 2503.

[0036] In this embodiment, an adjusting screw 33 is threadedly connected to the middle of the upper end cover 24. A knob 3301 is fixed to one end of the adjusting screw 33 that protrudes from the upper end cover 24. An adjusting panel 34 is rotatably sleeved at the lower end of the adjusting screw 33. The upper end of the adjusting spring 31 located in the upper cavity 2501 is fixedly connected to the adjusting panel 34, and the lower end of the adjusting spring 31 is fixedly connected to the adjusting plug 30 located in the upper cavity 2503.

[0037] In this embodiment, the jet pipe 27 has a diffuser-shaped structure with a smaller upper end and a larger lower end.

[0038] The preparation of SiC based on methylsilane specifically includes the following steps: Methylsilane, hydrogen, and argon are introduced into a mixing tank 1, where hydrogen is used as a carrier gas and argon as a dilution gas to mix with the methylsilane. The thoroughly mixed gas is then transported to a CVD furnace 2. A vacuum pump 3 is turned on to maintain the vacuum level in the CVD furnace 2, and the deposition temperature is controlled by heating. After the deposition time is reached, the vacuum state of the CVD furnace 2 is maintained for a cooling phase, during which a circulating cooling water tank 4 cools the CVD furnace 2. This controls the cooling time; after the CVD furnace 2 cools down to the safe opening temperature, the finished product is obtained by unloading; the unreacted methylsilane and byproducts produced in the CVD furnace 2 are discharged from the bottom of the CVD furnace 2 to the condensation recovery device 5, where they are cooled and recovered. The exhaust gas, carrying a small amount of dust, is filtered by the particle filter device 6 and then extracted by a vacuum pump. The exhaust gas is then treated in an alkaline solution before being discharged; the dust particles filtered by the particle filter device 6 are fed into the condensation recovery device 5.

[0039] Before using the particle filter device 6, the positions of the first adjusting disc 16, adjusting ring 18, and second adjusting disc 23 within the particle filter device 6 are calibrated to ensure that the working components at both ends of the feed pipe 9 of the particle filter device 6 are in two states: dust particle filtration and dust particle cleaning, respectively. During operation, the pipeline leading to the inlet of the vacuum pump 3 is connected to the particle filter device 6, and the airflow carrying dust particles enters the feed pipe 9 from the first feed inlet 901. The servo motor 13 is activated, driving the first adjusting disc 16 and adjusting ring 18. 8. The second adjusting turntable 23 rotates to adjust the working status of the working components at both ends of the feed pipe 9. As the output shaft of the servo motor 13 rotates, it drives the cleaning brush 20 to rotate relative to the particle filter screen 17, cleaning the dust particles filtered out on the particle filter screen 17. The output shaft of the servo motor 13 drives the first adjusting turntable 16, the adjusting ring 18, and the second adjusting turntable 23 to rotate, adjusting the position of the through holes on the first adjusting turntable 16, the adjusting ring 18, and the second adjusting turntable 23, thereby adjusting the working status of the working components at both ends of the feed pipe 9.

[0040] When the working part at the right end of the feed pipe 9 is in the dust particle filtering state, the right side of the feed pipe 9 is connected to the right first inner pipe 1001, the right first outer ring box 1002 is connected to the right second outer ring box 1102, and the right adjusting turntable 23 and the second partition 22 separate the discharge box 12 from the second inner pipe 1101. At this time, the airflow carrying dust particles enters the second inner pipe 1101 and is filtered by the particle filter screen 17. The dust particles are isolated in the second inner pipe 1101, and the filtered airflow enters the second outer ring box 1102. The dust then enters the first outer ring box 1002. At this time, the working part at the left end of the feed pipe 9 is in the dust particle cleaning state. At this time, the first adjusting turntable 16 and the first partition 15 on the left side of the feed pipe 9 separate the left first inner pipe 1001 from the left first inner pipe 1001. The adjusting ring 18 separates the left first outer ring box 1002 from the left second outer ring box 1102, and the discharge box 12 is connected to the second inner pipe 1101. At this time, the isolated dust particles are sucked into the dust discharge box 12 from the second inner pipe 1101 under the action of negative pressure.

[0041] After the airflow carrying dust particles enters the second inner pipe 1101, it is filtered by the particle filter 17 and the dust particles are isolated in the second inner pipe 1101. The filtered airflow enters the second outer ring box 1102 and then enters the first outer ring box 1002.

[0042] After filtration, the airflow entering the first outer ring box 1002 enters the middle cavity 2502 through the second feed port 2505. Then, it is split within the middle cavity 2502. Part of the airflow enters the upper cavity 2501 and is discharged from the third discharge pipe 2504 into the pump inlet of the vacuum pump 3. The other part of the airflow enters the lower cavity 2503 and is then sprayed through the converging nozzle 28 and the negative pressure pipe 26. Due to the Venturi effect, a negative pressure is generated at the part of the airflow passing through the negative pressure pipe 26, which draws the dust particles in the dust discharge box 12 into the negative pressure pipe and mixes with the sprayed airflow. The mixture is then blown from the spray pipe 27 into the condensation and recovery device, and the dust particles filtered by the particle filter 17 are recovered into the condensation and recovery device 5.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An apparatus for preparing SiC from methylsilane, comprising a mixing tank, a CVD furnace, a vacuum pump, a circulating cooling water tank, a condensation recovery device, and a particulate filter; the outlet of the mixing tank is connected to the inlet of the CVD furnace via a pipeline; the circulating cooling water tank is connected to the CVD furnace via a cooling water pipe; the exhaust gas outlet at the bottom of the CVD furnace is connected to the condensation recovery device via a pipeline; and the CVD furnace and the vacuum pump are connected via a pipeline. The apparatus is characterized in that: The particulate filter is installed in the pipeline between the CVD furnace and the vacuum pump. The particulate filter includes a filter assembly and a negative pressure cleaning assembly. The filter assembly includes a feed pipe, two discharge boxes symmetrically distributed on both sides of the feed pipe, two filter boxes, and two dust emission boxes. The feed pipe, discharge boxes, filter boxes, and dust emission boxes are connected in sequence. A servo motor is fixed to the end of the right dust emission box, and a sealing baffle is fixed to the end of the left dust emission box. The negative pressure cleaning assembly includes an upper end cover, a distribution box, a negative pressure pipe, and an injection pipe connected in sequence through a flange. The injection pipe has a diffuser-shaped structure with a small diameter at the upper end and a large diameter at the lower end. A converging spray pipe is installed inside the negative pressure pipe. The upper edge of the spray pipe is fixed between the lower end face of the distribution box and the upper end face of the negative pressure pipe.

2. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, The feed pipe is a horizontally placed cylindrical structure. A first feed port is provided on the upper side of the feed pipe. The first feed port is connected to the CVD furnace through a pipeline. A first partition is fixed inside the feed pipe near the left and right ports. An opening is provided in the middle of the first partition, and multiple through holes are evenly distributed around the opening in the middle of the first partition.

3. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, The discharge box consists of two parts: a first inner tube and a first outer ring box. The first outer ring box is a circular box structure surrounding the first inner tube. Multiple through holes leading to the first outer ring box are evenly distributed on the top end face of the discharge box. A first discharge port is provided on the lower side of the first outer ring box. A first adjusting turntable is provided in the groove formed between the bottom end of the discharge box and the first partition. The first adjusting turntable is fixedly connected to the output shaft of the servo motor. Through holes corresponding to the through holes on the first partition are evenly distributed on the first adjusting turntable.

4. The apparatus for preparing SiC from methylsilane according to claim 1, characterized in that, The filter box contains a fixed particle filter screen, which divides the filter box into a second inner tube and a second outer ring box. The second inner tube is connected to the first inner tube of the discharge box. Multiple through holes leading to the second outer ring box are evenly distributed on the bottom end face of the filter box, each corresponding to a through hole on the top of the discharge box. An adjusting ring is installed in the groove between the bottom end face of the filter box and the top end face of the discharge box. The inner side of the adjusting ring is fixedly connected to the output shaft of the servo motor via multiple evenly distributed first connecting rods. The adjusting ring has through holes corresponding to the through holes at the bottom of the filter box and the top of the discharge box. When the servo motor drives the adjusting ring to rotate until its through holes align with the through holes of the filter box and the discharge box, the second outer ring box is connected to the first outer ring box of the discharge box. Multiple cleaning brushes are evenly distributed around the output shaft of the servo motor on the inner side of the particle filter screen. The front of the cleaning brush is in contact with the surface of the particle filter screen, and the back is fixedly connected to the output shaft of the servo motor via second connecting rods. The two ends of the second connecting rods are fixed to the back of the cleaning brushes and the output shaft, respectively.

5. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, The dust emission box is a cylindrical structure with an opening at the left end, and a second discharge port is provided on the lower side of the dust emission box. A second partition is provided near the opening at the left end of the dust emission box. Both the second partition and the middle of the dust emission box are provided with openings to facilitate the passage of the output shaft of the servo motor. Multiple through holes are evenly distributed around the middle opening on the second partition. A second adjusting turntable is provided in the groove formed between the second partition and the top end face of the filter box. The second adjusting turntable is fixedly connected to the output shaft of the servo motor. The second adjusting turntable is evenly distributed with through holes corresponding to the through holes on the second partition.

6. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, The distribution box has two fixed third partitions in the middle, which divide the distribution box into three parts: an upper cavity, a middle cavity, and a lower cavity. The middle of the third partition has a through hole. The front of the upper and middle cavities has a third discharge port, which is connected to the pipeline leading to the vacuum pump. The side of the middle cavity has a second inlet, which is connected to the first discharge port through a pipeline. Adjusting plugs are installed in both the upper and lower cavities. The side of the adjusting plug near the third partition has a frustum-shaped structure with a smaller top and a larger bottom. By adjusting the distance between the adjusting plug and the third partition, the size of the gap between the frustum-shaped structure of the adjusting plug and the through hole in the middle of the third partition can be adjusted. Multiple pads are evenly distributed on the bottom edge of the adjusting plug, and an adjusting spring is installed on the back side of each adjusting plug.

7. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, The converging nozzle is larger at the top and smaller at the bottom, and a limit panel is provided at the upper port of the converging nozzle. Multiple third connecting rods are evenly distributed between the side edge of the limit panel and the inner side wall of the upper end of the converging nozzle. One end of the third connecting rod is fixedly connected to the converging nozzle, and the other end of the third connecting rod is fixedly connected to the side edge of the limit panel. The lower end of the adjusting spring located in the lower cavity is fixedly connected to the limit panel, and the upper end of the adjusting spring is fixedly connected to the adjusting plug located in the lower cavity.

8. The apparatus for preparing SiC from methylsilane according to claim 1 is characterized in that, An adjusting screw is threadedly connected to the middle of the upper end cover. A knob is fixed to one end of the adjusting screw that protrudes from the upper end cover. An adjusting panel is rotatably sleeved at the lower end of the adjusting screw. The upper end of the adjusting spring located in the upper cavity is fixedly connected to the adjusting panel, and the lower end of the adjusting spring is fixedly connected to the adjusting plug located in the upper cavity.

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