Ultrasonic cleaning equipment and method for high-purity silicon carbide particles

Abstract

The invention discloses ultrasonic cleaning equipment and method for high-purity silicon carbide particles. The ultrasonic cleaning equipment comprises a cleaning tank, a roller is horizontally arranged in the cleaning tank, and an ultrasonic generator is arranged at the bottom of the cleaning tank; silicon carbide particles to be cleaned are placed in the roller, meshes are evenly formed in the side face and the bottom face of the roller, and the hole diameter of the meshes is smaller than the particle diameter of the silicon carbide particles. The ultrasonic generator is used for carrying out ultrasonic cleaning on silicon carbide particles in the roller, the roller is driven by a roller driving system to rotate, a spraying water path is arranged in the roller, and the spraying water path enables impurities floating in the roller to directionally migrate along with a surface layer flow field so as to discharge separated graphite and dust out of the roller; graphite and fine dust attached to the surfaces of silicon carbide particles are separated and suspended in ultrapure water through mechanical rotation and the ultrasonic cavitation effect, the spraying head continuously discharges pollution in a directional mode while overflowing is conducted, and finally the cleaning purpose is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon carbide particle processing, and in particular relates to an ultrasonic cleaning device and method for high-purity silicon carbide particles. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Silicon carbide (SiC) is a widely used third-generation semiconductor material. It has the characteristics of wide bandgap, high breakdown field strength, and high electron mobility. Therefore, it is widely used in new energy vehicles, electronic power, and aerospace fields. In the silicon carbide single crystal growth process, silicon carbide synthetic materials are generally directly synthesized from silicon particles and graphite powder. After the processing process, a large amount of impurities such as graphite and fine dust will adhere to the surface of the particles. The purity of the silicon carbide synthetic material directly affects the quality and performance of the silicon carbide crystal. Therefore, it is necessary to clean the impurities attached to the surface of the silicon carbide particles under the action of ultrapure water and ultrasonic cleaning.

[0004] Currently, common cleaning methods include mechanical agitation cleaning, chemical cleaning, and ultrasonic cleaning, among which ultrasonic cleaning is more widely used. However, the existing technology still has the following problems: 1. Traditional ultrasonic cleaning equipment mostly uses fixed cleaning tanks, which cause uneven cleaning due to particle accumulation. It is also difficult to effectively separate light floating impurities (such as graphite) and sedimentary impurities, resulting in low cleaning efficiency.

[0005] 2. Existing equipment lacks optimized cleaning modes for different impurities. The ultrasonic frequency is fixed and cannot adapt to the differentiated cleaning needs of graphite (requires low frequency) and fine dust (requires high frequency). At the same time, floating impurities are easily retained on the liquid surface, lacking an effective surface stripping and directional discharge mechanism. In addition, silicon carbide particles are easily lost with the drainage during the cleaning process. Most existing equipment does not have an efficient recovery structure, resulting in waste of raw materials.

[0006] 3. Some equipment is made of metal or non-inert materials, which may introduce metal ions or organic contamination under strong ultrasonic action, affecting the purity of silicon carbide; at the same time, excessive manual intervention will cause secondary pollution, which is not suitable for mass production. Summary of the Invention

[0007] The purpose of the present invention is to provide an ultrasonic cleaning device and method for high-purity silicon carbide particles, which can achieve efficient cleaning of silicon carbide particles.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions: In the first aspect, an embodiment of the present invention provides an ultrasonic cleaning device for high-purity silicon carbide particles, comprising a cleaning tank, a horizontally arranged drum in the cleaning tank, and an ultrasonic generator at the bottom of the cleaning tank; the silicon carbide particles to be cleaned are placed in the drum, and mesh holes are evenly opened on the side and bottom of the drum, and the aperture of the mesh holes is smaller than the particle size of the silicon carbide particles; the ultrasonic generator ultrasonically cleans the silicon carbide particles in the drum, the drum is driven to rotate by a drum drive system, and a spray water channel is provided in the drum, and the spray water channel causes impurities floating in the drum to migrate directionally along the surface flow field to discharge the detached graphite and dust out of the drum.

[0009] As a further technical solution, the roller drive system includes a right-angle gear reduction motor, a driving gear, and a gear driven roller. The output shaft of the right-angle gear reduction motor is fixedly connected to the driving gear, and the driving gear is engaged with the gear on the gear driven roller. There are two gear driven rollers, and the two gear driven rollers are symmetrically arranged up and down.

[0010] As a further technical solution, the roller is located between two gear driven rollers, each gear driven roller is provided with two O-rings, and two annular raceways are provided on both sides of the roller corresponding to the four O-rings. The O-rings are located in the annular raceways, and the roller is driven to rotate by the friction between the O-rings and the annular raceways.

[0011] As a further technical solution, the spray water channel is driven by a push-pull spray system, which includes two push-pull cylinders, a spray water channel and a drum cover; the output end of the first push-pull cylinder is fixed to the spray water channel, driving the spray water channel to move, and the spray water channel passes through the center hole of the drum cover into the drum for spraying; the output end of the second push-pull cylinder is connected to the drum cover, driving the drum cover to move horizontally to realize the opening and closing of the drum.

[0012] As a further technical solution, one end of the spray water channel is connected to an ultrapure water hose, and the other end is connected to a fan-shaped spray head, and the fan-shaped spray head is placed in the drum.

[0013] As a further technical solution, the maximum height of the silicon carbide particles to be cleaned placed in the drum is lower than the lowest point of the drum cover, and the fan-shaped spray head is higher than the overflow water surface of the cleaning tank.

[0014] As a further technical solution, a water inlet and a drain are provided at the bottom of the cleaning tank, and the water inlet is connected to the ultrapure water pipeline.

[0015] As a further technical solution, the upper edge of the cleaning tank is serrated.

[0016] As a further technical solution, the roller drive system, roller, and push-pull spray system are all made of PP material.

[0017] In a second aspect, an embodiment of the present invention provides a method for ultrasonically cleaning high-purity silicon carbide particles, using the high-purity silicon carbide particle ultrasonic cleaning equipment described in the first aspect, comprising the following steps: The silicon carbide particles to be cleaned are placed in the drum through the end opening of the drum, and the open end of the drum is sealed with a drum cover; Start the drum drive system and ultrasonic generator. Under the synergistic effect of the drum rotation and the ultrasonic cavitation generated by the ultrasonic generator, the graphite and fine dust attached to the surface of the silicon carbide particles are separated. During the cleaning process, pure water continuously overflows, and at the same time, the spray water channel continuously sprays the water surface to discharge the detached graphite and fine dust out of the drum.

[0018] The beneficial effects of the above embodiments of the present invention are as follows: (1) The high-purity silicon carbide particle ultrasonic cleaning equipment of the present invention removes graphite and fine dust attached to the surface of silicon carbide particles through the rotation of the drum and ultrasonic cavitation. A water inlet is provided at the bottom of the cleaning tank, and pure water continuously overflows while ultrasonic waves are tumbling; mesh holes are provided on the sides and bottom of the drum to facilitate the discharge of impurities from the drum; the drum rotates 360 degrees and the speed is adjustable, and can be set to alternate forward and reverse rotation. The ultrasonic generator can output a 40kHz-120kHz sweep frequency for different impurities. The fan-shaped nozzle of the spray water channel sprays a fan-shaped water flow toward the water surface at a 30° inclination angle, causing floating impurities to migrate directionally along the surface flow field. The entire material of this equipment is PP material, which avoids secondary pollution. It has high cleaning efficiency and achieves a high degree of automated cleaning. (2) The roller drive system of the present invention is equipped with a flexible coupling structure of an O-ring and an annular raceway. The O-ring (fluororubber) of the driven roller is embedded in the annular raceway of the roller, transmitting power through friction, cushioning the impact load of the PP gear and avoiding tooth breakage caused by traditional rigid meshing. The push-pull spray system realizes dynamic roller closure. The roller cover is pushed and sealed by a cylinder. The spray water channel runs through the center of the cover. The fan-shaped nozzle (30° inclination) reciprocates and sprays in the roller, forming a directional water flow to push impurities to the overflow port. No human intervention is required throughout the process.

[0019] (3) The serrated structure on the upper edge of the cleaning tank of the present invention breaks the water surface tension, allowing floating graphite to be discharged preferentially with the overflow; the spray system sprays ultrapure water at a 30° angle to form a surface tangential flow field, which is conducive to the discharge of impurities from the drum; the double water channel design at the bottom of the cleaning tank (the water inlet continuously injects ultrapure water, and the drain outlet automatically discharges sewage) forms a dynamic update, and combined with the drum mesh, a closed loop of "zero particle loss and complete impurity discharge" is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 It is a schematic diagram of the overall structure of the high-purity silicon carbide particle ultrasonic cleaning equipment of the present invention; Figure 2 This is a front view of the internal structure of the high-purity silicon carbide particle ultrasonic cleaning equipment of the present invention; Figure 3 is a top view of the roller drive system of the present invention; Figure 4 It is a top view of the drum cover and the spray water channel of the present invention; Figure 5 It is a structural schematic diagram of the drum and the drum cover of the present invention; Figure 6 It is a bottom schematic diagram of the drum of the present invention; Figure 7 It is a side schematic diagram of the drum of the present invention; Figure 8 It is a schematic diagram of the maximum material height in the drum of the present invention.

[0022] The diagram is for illustrative purposes only; Among them, 1. right-angle gear reduction motor; 2. driving gear; 3. gear driven roller; 4. O-ring; 5. first push-pull cylinder; 6. second push-pull cylinder; 7. spray water channel; 8. fan-shaped spray head; 9. drum cover; 10. drum cover support rod; 11. drum; 12. cleaning tank; 13. water inlet; 14. water outlet; 15. ultrasonic generator; 16. annular raceway. DETAILED DESCRIPTION

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0024] Example 1 In a typical embodiment of the present invention, Figures 1 to 8As shown, a high-purity silicon carbide particle ultrasonic cleaning device is provided, including a cleaning tank 12, a roller 11 is horizontally arranged in the cleaning tank 12, and an ultrasonic generator 15 is arranged at the bottom of the cleaning tank 12; the silicon carbide particles to be cleaned are placed in the roller 11, and the side and bottom surfaces of the roller 11 are evenly provided with mesh holes, the aperture of the mesh holes is smaller than the particle size of the silicon carbide particles; the ultrasonic generator 15 ultrasonically cleans the silicon carbide particles in the roller 11, and the roller 11 is driven to rotate by a roller drive system. A spray water channel 7 is provided in the roller 11, and the spray water channel 7 causes impurities floating in the roller to migrate directionally along the surface flow field to discharge detached graphite and dust from the roller.

[0025] During the cleaning process of silicon carbide particles, the above device continuously rotates the drum (rather than static immersion) to fully turn the silicon carbide particles, completely avoiding cleaning dead corners caused by particle accumulation and significantly improving cleaning uniformity; Figure 6 and Figure 7 As shown, by setting appropriate mesh holes on the side and bottom of the drum, zero particle loss is ensured while allowing the stripped micron-sized graphite and dust to be discharged from the mesh holes, thereby achieving selective separation of impurities; during the cleaning process, ultrasonic cavitation is used to deeply strip off the surface attachments of silicon carbide, while directional spraying in the drum forms a dynamic water flow, which pushes light impurities to migrate to the overflow port. The two work together to overcome the problem that traditional equipment cannot remove both settling impurities and floating graphite at the same time, and can effectively improve the cleaning efficiency.

[0026] like Figure 3 As shown, the roller drive system includes a right-angle gear reduction motor 1, a driving gear 2, and a gear driven roller 3. The output shaft of the right-angle gear reduction motor 1 is fixedly connected to the driving gear 2. The driving gear 2 is engaged with the gear on the gear driven roller 3. There are two gear driven rollers 3, and the two gear driven rollers 3 are symmetrically arranged up and down.

[0027] Furthermore, the roller is located between two gear driven rollers 3, and two O-rings 4 are provided on each gear driven roller 3. Two annular raceways 16 are provided at positions corresponding to the four O-rings 4 on both sides of the roller. The O-rings 4 are located in the annular raceways 16, and the roller is driven to rotate by the friction between the O-rings 4 and the annular raceways 16.

[0028] During operation, the right-angle gear reduction motor 1 transmits power to the drive gear 2, thereby rotating the two gear driven rollers 3. The roller 11 is placed between the two gear driven rollers 3. The O-ring 4 on the gear driven roller 3 is placed in the annular raceway 16 on the roller. The friction between the O-ring 4 and the annular raceway 16 drives the roller to rotate. Because the entire device is made of PP, a rigid transmission between the gear driven roller 3 and the roller would easily cause wear and breakage. This transmission design achieves flexible power transmission and improves the power transmission fault tolerance.

[0029] Traditional gears directly meshing with the PP roller can easily break teeth. This embodiment utilizes a four-stage transmission system: drive gear 2 → driven gear roller 3 → O-ring 4 → roller. This system transmits power through friction between the O-ring 4 and the roller's annular raceway 16. This system offers the following advantages: The elastic deformation of the O-ring 4 (e.g., fluororubber) absorbs shock, preventing the PP gear from cracking due to rigid contact. The symmetrical layout of the dual driven gear rollers 3 and the four O-rings 4 ensures balanced force on the roller and stable speed. The annular raceway 16 constrains radial displacement of the O-ring 4, preventing slippage and enhancing particle tumbling.

[0030] like Figure 4 As shown, the push-pull spraying system includes two push-pull cylinders, a spraying water channel 7 and a drum cover 9; the output end of the first push-pull cylinder 5 is fixed to the spraying water channel 7, driving the spraying water channel 7 to move, and the spraying water channel 7 passes through the center hole of the drum cover 9 to enter the drum for spraying; the output end of the second push-pull cylinder 6 is connected to the drum cover 9 through the drum cover support rod 10, driving the drum cover 9 to move horizontally to realize the opening and closing of the drum.

[0031] Furthermore, one end of the spray water channel 7 is connected to an ultrapure water hose, and the other end is connected to a fan-shaped spray head 8, and the fan-shaped spray head 8 is placed in the drum.

[0032] The push-pull spray system of this embodiment drives the spray water channel 7 to move horizontally through the first push cylinder, and can send the fan-shaped spray head 8 into the drum, or move the fan-shaped spray head 8 out of the drum; Figure 5 As shown, the second push-pull cylinder 6 drives the drum cover 9 to move horizontally to realize the opening and closing of the drum. When the drum rotates, the drum cover 9 seals the drum to prevent the silicon carbide particles from falling from the drum. After cleaning is completed, the drum cover 9 is opened to take the cleaned silicon carbide particles out of the drum.

[0033] like Figure 8 As shown, the maximum height of the silicon carbide particles to be cleaned placed in the drum is lower than the lowest point of the drum cover 9. Due to the low speed of the drum, the material is pulled up to a certain height and naturally falls back, and the drum cover 9 fits well with the drum without friction, thus ensuring that the material will not escape. Figure 2As shown, when the drum is placed in the cleaning tank 12, the height of the drum is higher than the height of the cleaning tank 12. As long as the maximum height of the material can be guaranteed to be lower than the upper edge of the cleaning tank 12, and the height of the fan-shaped nozzle is slightly higher than the overflow water surface, the spray water channel 7 reciprocates during spraying, which is conducive to promoting the discharge of impurities.

[0034] In this embodiment, a water inlet 13 and a drain outlet are provided at the bottom of the cleaning tank 12. The water inlet 13 is connected to the ultrapure water pipeline. Ultrapure water is input into the cleaning tank 12 through the water inlet 13. After the material cleaning is completed, the water in the cleaning tank 12 is discharged through the drain outlet.

[0035] In this embodiment, the upper edge of the cleaning tank 12 is serrated, which is conducive to overflowing and discharging impurities floating on the water surface.

[0036] In this embodiment, the roller drive system, the roller, and the push-pull spraying system are all made of PP material, which is not prone to secondary pollution.

[0037] The working principle of the high-purity silicon carbide particle ultrasonic cleaning equipment provided in this embodiment is as follows: Place silicon carbide particles in the drum, the maximum material height is as follows Figure 8 As shown, the second push-pull cylinder 6 is controlled by the operating panel to close the drum cover 9, and ultrapure water enters from the water inlet 13 of the cleaning tank 12 until the cleaning tank 12 is full and the water inlet stops. At this time, the water level is flush with the upper edge of the cleaning tank 12 and submerges the materials. The ultrasonic generator and the right-angle gear reduction motor 1 are turned on, and the first push-pull cylinder 5 is turned on to control the reciprocating motion of the spray water channel 7. At the same time, the fan-shaped spray head 8 starts spraying. The silicon carbide particles are ultrasonically excited and tumbled in the drum. The rotation of the drum and the ultrasonic cavitation effect separate the graphite and fine dust attached to the surface of the silicon carbide particles, causing the attached graphite and fine dust to float on the water surface. The pure water in the cleaning tank 12 continuously overflows, and the spraying is combined with the floating impurities to migrate directionally along the surface flow field, making it easier for the impurities to be discharged from the sides and bottom of the drum, thereby reducing the impurities and achieving the purpose of continuous cleaning.

[0038] The high-purity silicon carbide particle ultrasonic cleaning equipment provided in this embodiment is made of PP material as a whole, which can avoid secondary pollution. The equipment realizes the coordination of mechanical tumbling and ultrasonic waves, and also has the function of spraying and draining sewage. It not only has high cleaning efficiency but also achieves a high degree of automated cleaning.

[0039] Example 2 In a typical embodiment of the present invention, a method for ultrasonic cleaning of high-purity silicon carbide particles is provided, comprising the following steps: The silicon carbide particles to be cleaned are placed in the drum through the end opening of the drum, and the open end of the drum is sealed with a drum cover; Start the drum drive system and ultrasonic generator. Under the synergistic effect of the drum rotation and the ultrasonic cavitation generated by the ultrasonic generator, the graphite and fine dust attached to the surface of the silicon carbide particles are separated. During the cleaning process, pure water continuously overflows, and at the same time, the spray water channel continuously sprays the water surface to discharge the detached graphite and fine dust out of the drum.

[0040] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An ultrasonic cleaning device for high-purity silicon carbide particles, characterized in that: The invention comprises a cleaning tank, wherein a drum is horizontally arranged in the cleaning tank, and an ultrasonic generator is arranged at the bottom of the cleaning tank; silicon carbide particles to be cleaned are placed in the drum, and mesh holes are evenly opened on the side and bottom of the drum, and the aperture of the mesh holes is smaller than the particle size of the silicon carbide particles; the ultrasonic generator ultrasonically cleans the silicon carbide particles in the drum, and the drum is driven to rotate by a drum drive system. A spray water channel is arranged in the drum, and the spray water channel causes impurities floating in the drum to migrate directionally along the surface flow field, so as to discharge the detached graphite and dust out of the drum.

2. The high-purity silicon carbide particle ultrasonic cleaning equipment according to claim 1, characterized in that: The roller drive system includes a right-angle gear reduction motor, a driving gear, and a gear driven roller. The output shaft of the right-angle gear reduction motor is fixedly connected to the driving gear. The driving gear is engaged with the gear on the gear driven roller. Two gear driven rollers are provided, and the two gear driven rollers are symmetrically arranged up and down.

3. The high-purity silicon carbide particle ultrasonic cleaning device according to claim 2, characterized in that: The roller is located between two gear driven rollers, and each gear driven roller is provided with two O-rings. Two annular raceways are provided on both sides of the roller corresponding to the four O-rings. The O-rings are located in the annular raceways, and the roller is driven to rotate by the friction between the O-rings and the annular raceways.

4. The high-purity silicon carbide particle ultrasonic cleaning equipment according to claim 1, characterized in that: The spray water channel is driven by a push-pull spray system, which includes two push-pull cylinders, a spray water channel and a drum cover; the output end of the first push-pull cylinder is fixed to the spray water channel, driving the spray water channel to move, and the spray water channel passes through the center hole of the drum cover to enter the drum for spraying; the output end of the second push-pull cylinder is connected to the drum cover, driving the drum cover to move horizontally to realize the opening and closing of the drum.

5. The high-purity silicon carbide particle ultrasonic cleaning equipment according to claim 4, characterized in that: One end of the spray water channel is connected to an ultrapure water hose, and the other end is connected to a fan-shaped spray head, and the fan-shaped spray head is placed in the drum.

6. The high-purity silicon carbide particle ultrasonic cleaning device according to claim 5, characterized in that: The maximum height of the silicon carbide particles to be cleaned placed in the drum is lower than the lowest point of the drum cover, and the fan-shaped spray head is higher than the overflow water surface of the cleaning tank.

7. The high-purity silicon carbide particle ultrasonic cleaning equipment according to claim 1, characterized in that: A water inlet and a drain are provided at the bottom of the cleaning tank, and the water inlet is connected to the ultrapure water pipeline.

8. The high-purity silicon carbide particle ultrasonic cleaning equipment according to claim 1, characterized in that: The upper edge of the cleaning tank is serrated.

9. The high-purity silicon carbide particle ultrasonic cleaning device according to claim 1, characterized in that: The roller drive system, roller, push-pull spray system are all made of PP material.

10. A method for ultrasonic cleaning of high-purity silicon carbide particles, using the ultrasonic cleaning equipment for high-purity silicon carbide particles according to any one of claims 1 to 9, characterized in that: The following steps are involved: The silicon carbide particles to be cleaned are placed in the drum through the end opening of the drum, and the open end of the drum is sealed with a drum cover; Start the drum drive system and ultrasonic generator. Under the synergistic effect of the drum rotation and the ultrasonic cavitation generated by the ultrasonic generator, the graphite and fine dust attached to the surface of the silicon carbide particles are separated. During the cleaning process, pure water continuously overflows, and at the same time, the spray water channel continuously sprays the water surface to discharge the detached graphite and fine dust out of the drum.

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