A stable submicron silicon carbide classification device

Abstract

The present application relates to the technical field of silicon carbide production, and discloses a stable submicron silicon carbide grading device, which comprises a fixed rack, a raw material storage tank, a steam feeder, a crushing grading tank, a multilayer grading tank and a plurality of collecting tanks. In the present application, under the centrifugal action generated by the upward spiral of high-temperature steam, the maximum inner diameter of the plurality of grading zones decreases from bottom to top, the silicon carbide particles with larger particle size are first intercepted by the grading zones with larger inner diameter, and the silicon carbide particles with smaller particle size continue to rise in the high-temperature steam, so that the silicon carbide particles with different particle sizes are sequentially deposited and separated on the inner walls of the multilayer grading tank in each grading zone, can enter each collecting tank from each grading zone for collection, and the graded silicon carbide particles do not need to be further impurity-removed, the purity of the graded silicon carbide can be effectively improved, and the grading effect of the silicon carbide can be effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide production technology, specifically to a stable submicron silicon carbide grading device. Background Technology

[0002] Currently, the production of green silicon carbide micron powder (submicron-sized silicon carbide) in my country mainly uses finished green silicon carbide sand as raw material. Most manufacturers use ball mills for wet grinding to pulverize the raw material to below 63μm. After wet magnetic separation to remove iron, it undergoes acid and alkali treatment, and then is sorted to obtain silicon carbide raw materials of various grades for different applications. Currently, the grading of silicon carbide mixed with silicon powder mainly adopts pneumatic classification and hydraulic classification. Hydraulic classification uses two methods: overflow and sedimentation. Generally, micron powder with a particle size > W10 is classified by overflow, while particle size < W10 is classified by sedimentation. After particle size classification, dehydration is carried out to remove a large amount of water and then dried. The agglomerated dried material is then loosened by sieving to obtain different grades of submicron-sized silicon carbide. Pneumatic classification uses high-pressure gas to flush silicon carbide mixed with silicon powder. Since silicon carbide particles of different mesh sizes have different weights, under the same air force, silicon carbide of different mesh sizes will accumulate in different positions, thus achieving silicon carbide grading.

[0003] Existing pneumatic classification methods for silicon carbide typically employ multi-stage cyclone separation. This process requires multiple stages of equipment for separation. While the separation effect is good, the large number of equipment required for multi-stage separation results in high energy consumption. In classification processes where high precision is not required, the high cost makes it unprofitable. Furthermore, existing pneumatic classification methods can only classify silicon carbide of the current particle size and cannot further crush the silicon carbide during the classification process. A significant amount of airflow during pneumatic classification is intercepted and wasted by devices such as bag filters that capture silicon carbide, making it difficult to obtain a sufficient number of smaller silicon carbide particles and resulting in substantial energy waste.

[0004] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0005] In view of the shortcomings of the existing technology and to solve the above-mentioned technical problems, the present invention provides a stable submicron silicon carbide grading device.

[0006] This invention provides the following technical solution: a stable submicron silicon carbide grading device, comprising: a fixed frame, wherein a raw material storage tank, a steam supply, a crushing and grading tank, a multi-layer grading tank, and several collection tanks are sequentially fixed inside the fixed frame; several feed pipes are provided between the raw material storage tank, the steam supply, and the crushing and grading tanks, the feed pipes being used to connect to the raw material storage tank, the steam supply, and the crushing and grading tanks respectively, and the high-temperature steam provided by the steam supply through the feed pipes carries the silicon carbide raw material to be graded from the raw material storage tank into the crushing and grading tanks; each of the feed pipes is evenly distributed around the outer periphery of the crushing and grading tanks, and the conveying path of each feed pipe is tangent to the inner wall of the crushing and grading tanks; the crushing and grading tanks... The interior is equipped with spiral patterns, which provide additional collision surfaces for the silicon carbide raw material to be classified as it enters the crushing and classifying tank. The high-temperature steam supplied by the steam supply generates centrifugal force inside the crushing and classifying tank, which carries the smaller particles of silicon carbide raw material upward into a multi-layer classifying tank. The larger particles of silicon carbide raw material remain inside the crushing and classifying tank for further collision and crushing. The multi-layer classifying tank includes several classification zones, the maximum inner diameter of which decreases sequentially from bottom to top. Under the centrifugal force generated by the spiral ascent of the high-temperature steam, the silicon carbide raw material entering the multi-layer classifying tank is deposited and separated on the inner wall of the multi-layer classifying tank where each classification zone is located, and then enters a collection tank from each classification zone for collection.

[0007] Preferably, the feed pipe includes a feed branch pipe, an air inlet pipe, and a mixing pipe. One end of the feed branch pipe is connected to the raw material storage tank, and the other end of the feed branch pipe is connected to the side of the air inlet pipe near the mixing pipe. Both ends of the air inlet pipe are connected to the steam supplier and the mixing pipe, respectively, and the end of the mixing pipe away from the air inlet pipe is connected to the crushing and grading tank.

[0008] Preferably, the total length of the air inlet pipe and the mixing pipe of each of the feed pipes is equal, the number of feed pipes is even, and the conveying direction of the mixing pipe of two adjacent feed pipes to the crushing and classifying tank is opposite; each pair of adjacent feed pipes forms a convection pipe group, and within a convection pipe group, the conveying directions of the two mixing pipes are symmetrical and the conveying directions of the two mixing pipes are the same.

[0009] Preferably, the spiral pattern includes a positive thread and a negative thread, the pitch of the positive thread and the negative thread are equal, the positive thread and the negative thread are intersected, and the thread directions of the positive thread and the negative thread are opposite.

[0010] Preferably, the steam supplier includes a connecting pipe, a filter, a thermostat, and a speed controller arranged in sequence. The connecting pipe is used to connect with a steam generator to obtain high-temperature steam. The filter is used to filter impurities inside the high-temperature steam and adsorb excess moisture in the high-temperature steam. The thermostat is used to reheat the high-temperature steam and maintain its temperature. The speed controller is used to adjust the flow rate of the high-temperature steam entering the air inlet pipes of each of the feed pipes.

[0011] Preferably, a metering valve is provided at the connection between the raw material storage tank and the feed branch of each feed pipe. The opening time of each metering valve and the amount of silicon carbide raw material to be graded passing through each opening time are equal. Within the same time period, the amount of silicon carbide raw material inside each feed pipe is equal, and the flow rate of high-temperature steam inside each feed pipe is equal.

[0012] Preferably, a collection channel is provided on the inner surface of the multi-layer grading tank and within each grading zone, and a collection impeller is provided at the center of the top of the multi-layer grading tank; the multi-layer grading tank can divide the silicon carbide raw material entering the multi-layer grading tank into n+1 levels according to the number of grading zones n, and each level of silicon carbide raw material is collected separately through several collection channels and collection impellers before entering each collection tank.

[0013] Preferably, the collection channel includes several sub-channels and a main channel. The inclination angle of the sub-channels is greater than that of the main channel. A grading opening is provided at the bottom of the main channel, and each grading opening is connected to a corresponding collection tank via a pipeline. Within a grading zone, under the action of gravity, the silicon carbide raw materials collected from each sub-channel converge into the main channel and then enter the corresponding collection tank through the grading opening for collection.

[0014] Preferably, a drive motor is provided on one side of the collecting impeller, and the collecting impeller rotates under the action of the drive motor. A collection pipe is provided in the center of the collecting impeller in a direction away from the drive motor and extends through the multi-layer classifying tank. High-temperature steam carries the silicon carbide raw material with the smallest particle size spirally upward inside the multi-layer classifying tank until it passes through the rotating collecting impeller and enters the collection pipe provided in the center of the collecting impeller. After sedimentation treatment, the silicon carbide raw material with the smallest particle size enters a collection tank and is collected.

[0015] Compared with the prior art, the present invention provides a stable submicron silicon carbide classification device, which has the following beneficial effects:

[0016] 1. This stable submicron silicon carbide grading device involves silicon carbide raw materials to be graded being carried by high-temperature steam into a pulverizing and grading tank via feed pipes. Since each feed pipe is evenly distributed around the outer periphery of the pulverizing and grading tank, and the conveying path of each pipe is tangential to the inner wall of the tank, the silicon carbide raw materials are divided into multiple inlets and evenly enter the pulverizing and grading tank. Furthermore, the action of the inner wall of the pulverizing and grading tank generates a spiral airflow, and the spiral grooves on the inner wall provide a spiral collision surface, thereby increasing the contact area between the silicon carbide raw materials and between the raw materials and the interior of the pulverizing and grading tank. The collision probability between the walls is such that the silicon carbide raw material to be classified can be further crushed through the above two collisions. The spiral motion of the high-temperature steam entering the crushing and classifying tank generates centrifugal force inside the crushing and classifying tank, which throws out the silicon carbide raw material with a larger particle size to collide with the spiral pattern on the inner wall of the crushing and classifying tank, further improving the collision effect of the silicon carbide raw material. While ensuring the crushing efficiency inside the crushing and classifying tank, the centrifugal force generated by the spiral motion of the high-temperature steam can classify silicon carbide raw materials of different particle sizes inside the crushing and classifying tank. The silicon carbide raw material with a smaller particle size can move upward inside the crushing and classifying tank with the high-temperature steam and be transported into the multi-layer classifying tank for further classification.

[0017] 2. This stable submicron silicon carbide grading device, when silicon carbide raw material enters the multi-layer grading tank, is centrifuged by the spiral ascent of high-temperature steam. As the maximum inner diameter of several grading zones decreases sequentially from bottom to top, larger silicon carbide particles are first intercepted by the grading zones with larger inner diameters, while smaller silicon carbide particles continue to rise in the high-temperature steam. This causes silicon carbide particles of different sizes to be deposited and separated sequentially on the inner wall of the multi-layer grading tank where each grading zone is located, and finally collected from each grading zone into each collection tank. Furthermore, the graded silicon carbide particles do not require further impurity removal, which can effectively improve the purity of the graded silicon carbide and effectively ensure the grading effect of silicon carbide.

[0018] 3. In this stable submicron silicon carbide classification device, inside a multi-layer classification tank, silicon carbide particles are subjected to centrifugal force generated by the spiraling upward airflow. Larger silicon carbide particles are distributed in the outer layer of the spiraling upward airflow, while smaller silicon carbide particles are distributed in the inner layer. As the maximum inner diameter of the classification zones decreases sequentially from bottom to top, larger silicon carbide particles are first intercepted by the lower classification zone, while smaller silicon carbide particles continue upward. Silicon carbide particles of different sizes are sequentially intercepted and classified by each classification zone. Finally, the uninterrupted silicon carbide particles enter the collection pipe inside the collection impeller through the gaps between the continuously rotating collection impeller driven by the drive motor. The silicon carbide particles intercepted in each classification zone slide down along each sub-channel and converge into the main channel. Finally, they enter the corresponding collection tank for collection through the classification opening at the bottom of the main channel. The output from the collection pipe includes the lowest-sized silicon carbide particles and high-temperature steam. After sedimentation treatment, the lowest-sized silicon carbide raw material enters a collection tank for collection, completing the silicon carbide classification. Attached Figure Description

[0019] Figure 1 This is one of the three-dimensional structural schematic diagrams of the present invention;

[0020] Figure 2 This is a second three-dimensional structural schematic diagram of the present invention;

[0021] Figure 3 This is a three-dimensional structural diagram of the raw material storage tank and steam supply device of the present invention.

[0022] Figure 4 This is a three-dimensional structural diagram of the pulverizing and classifying tank of the present invention;

[0023] Figure 5 This is a cross-sectional schematic diagram of the crushing and classifying tank of the present invention;

[0024] Figure 6 This is a three-dimensional structural diagram of the multi-layer grading tank of the present invention;

[0025] Figure 7 This is a schematic diagram of the internal structure of the multi-layer grading tank of the present invention;

[0026] Figure 8 This is a three-dimensional structural diagram of the collecting impeller of the present invention.

[0027] In the diagram: 1. Fixed frame; 2. Raw material storage tank; 21. Metering valve; 3. Steam supply; 5. Crushing and classifying tank; 51. Spiral pattern; 511. Positive thread; 512. Negative thread; 6. Multi-layer classifying tank; 61. Classification zone; 62. Collection channel; 621. Sub-channel; 622. Main channel; 623. Classification opening; 63. Collection impeller; 64. Drive motor; 65. Collection pipe; 7. Collection tank; 8. Feed pipe; 81. Feed branch pipe; 82. Air inlet pipe; 83. Mixing pipe. Detailed Implementation

[0028] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] As described in the background section, there are shortcomings in the existing technology. In order to solve the above-mentioned technical problems, this application proposes a stable submicron silicon carbide classification device.

[0030] Please see Figures 1-8 A stable submicron silicon carbide grading device includes: a fixed frame 1, inside which a raw material storage tank 2, a steam supply 3, a crushing and grading tank 5, a multi-layer grading tank 6, and several collection tanks 7 are sequentially fixed; several feed pipes 8 are provided between the raw material storage tank 2, the steam supply 3, and the crushing and grading tank 5, respectively connecting the raw material storage tank 2, the steam supply 3, and the crushing and grading tank 5, and the high-temperature steam provided by the steam supply 3 through the feed pipes 8 carries the silicon carbide raw material to be graded from the raw material storage tank 2 into the crushing and grading tank 5; each feed pipe 8 is evenly distributed on the outer periphery of the crushing and grading tank 5, and the conveying path of each feed pipe 8 is tangent to the inner wall of the crushing and grading tank 5; the interior of the crushing and grading tank 5 is provided with a spiral pattern. 51. The spiral pattern 51 is used to provide an additional collision surface for the silicon carbide raw material to be classified as it enters the crushing and classifying tank 5. The high-temperature steam supplied by the steam supply unit 3 generates centrifugal force inside the crushing and classifying tank 5, which conveys the smaller particles of the silicon carbide raw material inside the crushing and classifying tank 5 upward into the multi-layer classifying tank 6. The larger particles of the silicon carbide raw material remain inside the crushing and classifying tank 5 and continue to collide and be crushed. The multi-layer classifying tank 6 includes several classification zones 61. The maximum inner diameter of the several classification zones 61 decreases from bottom to top. The silicon carbide raw material entering the multi-layer classifying tank 6 is deposited and separated on the inner wall of the multi-layer classifying tank 6 where each classification zone 61 is located under the centrifugal force generated by the spiral rise of the high-temperature steam, and enters each collection tank 7 from each classification zone 61 for collection.

[0031] In use, silicon carbide raw materials to be graded are pre-stored inside the raw material storage tank 2. Under the flow of high-temperature steam (high-temperature steam refers to steam with a temperature greater than 145°C) provided by the steam supplier 3, a negative pressure is generated by the rapid flow inside each feed pipe 8, drawing the silicon carbide raw materials to be graded from the raw material storage tank 2 into the feed pipe 8. The silicon carbide raw materials to be graded are dispersed inside the high-temperature steam under the flow of the high-temperature steam and, carried by the high-temperature steam, enter the crushing and grading tank 5 along the path of the feed pipe 8. Since each feed pipe 8 is evenly distributed on the outer periphery of the crushing and grading tank 5, the conveying path of each feed pipe 8 is consistent with... The inner walls of the crushing and classifying tank 5 are tangential, allowing the silicon carbide raw material to be classified to enter the crushing and classifying tank 5 evenly through multiple inlets via the various feed pipes 8. The inner walls of the crushing and classifying tank 5 create a spiral airflow, and the spiral patterns 51 on the inner walls provide a spiral collision surface, increasing the probability of collisions between the silicon carbide raw materials and between the raw materials and the inner walls of the crushing and classifying tank 5. This effectively further crushes the silicon carbide raw material through these two types of collisions, and the material is then processed through the crushing and classifying tank. The spiral motion of the high-temperature steam inside tank 5 generates centrifugal force, throwing larger silicon carbide particles to collide with the spiral patterns on the inner wall of tank 5. This further enhances the collision effect of the silicon carbide particles, ensuring the pulverization efficiency within tank 5. Simultaneously, the centrifugal force generated by the spiral motion of the high-temperature steam within tank 5 classifies silicon carbide particles of different sizes. Lower-sized silicon carbide particles move upwards with the high-temperature steam within tank 5 and are conveyed into multi-layer classifier 6 for further classification. The silicon carbide particles entering multi-layer classifier 6... Under the centrifugal force generated by the spiral ascent of high-temperature steam, as the maximum inner diameter of several classification zones 61 decreases sequentially from bottom to top, larger silicon carbide particles are first intercepted by the classification zones 61 with larger inner diameters, while smaller silicon carbide particles continue to rise in the high-temperature steam. This causes silicon carbide particles of different sizes to be deposited and separated sequentially on the inner wall of the multi-layer classification tank 6 where each classification zone 61 is located, and finally collected from each classification zone 61 into each collection tank 7. Furthermore, the classified silicon carbide particles do not need to be purified again, which can effectively improve the purity of the classified silicon carbide and effectively ensure the classification effect of silicon carbide.

[0032] Further, please refer to Figures 1-3The feed pipe 8 includes a feed branch pipe 81, an air inlet pipe 82, and a mixing pipe 83. One end of the feed branch pipe 81 is connected to the raw material storage tank 2, and the other end of the feed branch pipe 81 is connected to the side of the air inlet pipe 82 near the mixing pipe 83. The two ends of the air inlet pipe 82 are connected to the steam supplier 3 and the mixing pipe 83, respectively. The end of the mixing pipe 83 away from the air inlet pipe 82 is connected to the crushing and classifying tank 5.

[0033] The total lengths of the air inlet pipe 82 and the mixing pipe 83 of the feed pipe 8 are equal. The number of feed pipes 8 is even. The mixing pipes 83 of two adjacent feed pipes 8 convey to the crushing and classifying tank 5 in opposite directions. Each pair of adjacent feed pipes 8 forms a convection pipe group. Within a convection pipe group, the conveying directions of the two mixing pipes 83 are symmetrical and the conveying directions of the two mixing pipes 83 are the same.

[0034] During use, since the total length of the air inlet pipe 82 and the mixing pipe 83 of each feed pipe 8 is equal, the high-temperature steam entering from the inlet of each air inlet pipe 82 has the same flow rate and temperature. After entraining the silicon carbide raw material to be classified at the feed reduction branch pipe 81, when it enters the crushing and classifying tank 5, the amount of silicon carbide raw material, the temperature of the high-temperature steam, and the flow rate are all equal in each feed pipe 8. This ensures that silicon carbide material is uniformly supplied to each inlet of the crushing and classifying tank 5, and also ensures the uniformity of the crushing and classifying medium (high-temperature steam) inside the crushing and classifying tank 5. Furthermore, it ensures uniformity in a convection pipe. Inside the group, the two mixing pipes 83 are symmetrical in their conveying directions. The same conveying direction of the two mixing pipes 83 allows the two silicon carbide particles to be classified to collide more fully through the conveying path of high-temperature steam in the same direction. The symmetrical conveying relationship increases the collision probability. The inner wall of the crushing and classifying tank 5 restricts and guides the path of the high-temperature steam inside the crushing and classifying tank 5, so that the high-temperature steam can move and collide in an orderly manner inside the crushing and classifying tank 5, and finally generate a spiral upward airflow to classify the silicon carbide raw material to be classified.

[0035] Further, please refer to Figures 4-5 The spiral pattern 51 includes a positive thread 511 and a negative thread 512. The pitch of the positive thread 511 and the negative thread 512 is equal. The positive thread 511 and the negative thread 512 are intersected and their thread directions are opposite. Thus, by intersecting the positive thread 511 and the negative thread 512, the thread density in the same area is increased. This can more effectively increase the additional collision surface of the silicon carbide raw material to be classified into the crushing and classifying tank 5, further increase the collision probability of the silicon carbide raw material, and ensure the crushing efficiency inside the crushing and classifying tank 5.

[0036] Further, please refer to Figures 1-3The steam supply unit 3 includes a connecting pipe, a filter, a thermostat, and a speed controller arranged in sequence. The connecting pipe is used to connect with the steam generator to obtain high-temperature steam. The filter is used to filter impurities inside the high-temperature steam and adsorb excess moisture in the high-temperature steam. The thermostat is used to reheat the high-temperature steam and maintain its temperature. The speed controller is used to adjust the flow rate of the high-temperature steam entering the air inlet pipe 82 of each feed pipe 8.

[0037] A metering valve 21 is installed at the connection between the raw material storage tank 2 and the feed branch pipe 81 of each feed pipe 8. The opening time of each metering valve 21 and the amount of silicon carbide raw material to be graded passing through each opening time are equal. During the same time period, the amount of silicon carbide raw material inside each feed pipe 8 is equal, and the flow rate of high-temperature steam inside each feed pipe 8 is equal.

[0038] High-temperature steam is obtained by connecting to a steam generator through a connecting pipe. The filter filters out impurities inside the high-temperature steam and adsorbs excess moisture in the high-temperature steam. The thermostat reheats the high-temperature steam to maintain its temperature. The speed controller adjusts the flow rate of the high-temperature steam entering the air inlet pipes 82 of each feed pipe 8 (in use, the filter, thermostat, and speed controller are all common technical solutions in the prior art, and their specific working principles and control schemes are also common technical solutions in the prior art, which will not be elaborated here). This ensures that the high-temperature steam entering through each air inlet pipe 82 can maintain a consistent temperature, humidity, and speed. Furthermore, through each metering valve 21 with an equal opening time for each segment, the amount of silicon carbide raw material to be classified carried by the high-temperature steam is equal. This ensures the uniformity of the silicon carbide raw material and the crushing and classification medium (high-temperature steam) entering the crushing and classification tank 5 through each feed pipe 8, further improving the crushing and classification effect inside the crushing and classification tank 5.

[0039] Further, please refer to Figures 6-8 The multi-layer grading tank 6 has a collection channel 62 on its inner surface and located inside each grading zone 61. A collection impeller 63 is located at the center of the top of the multi-layer grading tank 6. The multi-layer grading tank 6 can divide the silicon carbide raw material entering the multi-layer grading tank 6 into n+1 levels according to the number n of grading zones 61. Each level of silicon carbide raw material is collected separately through several collection channels 62 and collection impellers 63 and then enters each collection tank 7.

[0040] The collection channel 62 includes several sub-channels 621 and a main channel 622. The inclination angle of the sub-channels 621 is greater than that of the main channel 622. A grading opening 623 is provided at the bottom of the main channel 622. Each grading opening 623 is connected to a corresponding collection tank 7 by a pipeline. Inside a grading zone 61, under the action of gravity, the silicon carbide raw materials collected from each sub-channel 621 converge into the main channel 622 and then enter the corresponding collection tank 7 for collection through the grading opening 623.

[0041] A drive motor 64 is provided on one side of the collecting impeller 63. The collecting impeller 63 rotates under the action of the drive motor 64. A collection pipe 65 is provided in the center of the collecting impeller 63, away from the drive motor 64, and extends through the multi-layer classifier 6. High-temperature steam carries the silicon carbide raw material with the smallest particle size to spiral upward inside the multi-layer classifier 6 until it passes through the rotating collecting impeller 63 and enters the collection pipe 65 provided in the center of the collecting impeller 63. After sedimentation, the silicon carbide raw material with the smallest particle size enters a collecting tank 7 and is collected.

[0042] Therefore, during use, the silicon carbide particles, after initial classification in the crushing and classifying tank 5, enter the multi-layer classifying tank 6 with high-temperature steam. The high-temperature steam generates a spiraling upward airflow inside the multi-layer classifying tank 6. Under the action of this spiraling upward airflow, the silicon carbide particles are subjected to centrifugal force. Larger silicon carbide particles are distributed in the outer layer of the spiraling upward airflow, while smaller silicon carbide particles are distributed in the inner layer. Because the maximum inner diameter of the classification zones 61 decreases sequentially from bottom to top, larger silicon carbide particles are first retained by the lower classification zone 61, while smaller silicon carbide particles continue upward. Silicon carbide particles of different sizes are sequentially retained and classified by each classification zone 61. Finally, the unretained silicon carbide particles enter the collecting impeller 63 through the gaps between the impellers, which rotate continuously under the drive motor 64. 3. Internal collection pipe 65; Silicon carbide particles intercepted in each classification zone 61 slide down along each sub-channel 621 and converge into the main channel 622. Finally, they enter the corresponding collection tank 7 through the classification opening 623 at the bottom of the main channel 622. In actual use, the collection tank 7 is additionally equipped with a negative pressure mechanism. This negative pressure mechanism is a common negative pressure machine, which can provide a certain negative pressure that does not affect the airflow inside the multi-layer classification tank 6, and assist the classified silicon carbide to enter the collection tank 7. The output from the collection pipe 65 includes the lowest particle size silicon carbide particles and high-temperature steam. After sedimentation treatment (in actual use, a bag filter is used to separate the silicon carbide particles and high-temperature steam, and the high-temperature steam is recovered and reused), the lowest particle size silicon carbide raw material enters a collection tank 7 and is collected, completing the classification of silicon carbide.

[0043] Working principle:

[0044] In use, silicon carbide raw materials to be graded are pre-stored in the raw material storage tank 2. The steam supply unit 3 is connected to the steam generator via a connecting pipe to obtain high-temperature steam. A filter removes impurities from the high-temperature steam and adsorbs excess moisture. A thermostat reheats the high-temperature steam to maintain its temperature. A speed controller adjusts the flow rate of the high-temperature steam entering the air inlet pipes 82 of each feed pipe 8, ensuring that the high-temperature steam entering through each air inlet pipe 82 maintains consistent temperature, humidity, and speed. Furthermore, through each metering valve 21 with equal opening times for each segment, the amount of silicon carbide raw materials to be graded carried by the high-temperature steam is equal. Since the total length of the air inlet pipes 82 and mixing pipes 83 of each feed pipe 8 is equal, the high-temperature steam entering from the inlet of each air inlet pipe 82, with equal flow rate and temperature, carries the silicon carbide raw materials to be graded at the feed reduction branch pipe 81. When the silicon carbide raw material enters the crushing and classifying tank 5, the amount of silicon carbide raw material, the temperature of the high-temperature steam, and the flow rate are all equal in each feed pipe 8. This ensures that silicon carbide material is uniformly supplied to each inlet of the crushing and classifying tank 5, and also ensures the uniformity of the crushing and classifying medium (high-temperature steam) inside the crushing and classifying tank 5. Furthermore, within a convection pipe group, the conveying directions of the two mixing pipes 83 are symmetrical and the conveying directions of the two mixing pipes 83 are the same. This allows the two silicon carbide particles to be classified to collide more fully through the conveying path of the high-temperature steam with the same direction. The symmetrical conveying relationship increases the collision probability, and the inner wall of the crushing and classifying tank 5 restricts and guides the path of the high-temperature steam inside the crushing and classifying tank 5. This allows the high-temperature steam to move and collide in an orderly manner inside the crushing and classifying tank 5, and finally generates a spiral upward airflow to classify the silicon carbide raw material to be classified.

[0045] The silicon carbide raw materials to be classified are dispersed within the high-temperature steam flow and, carried by the steam, enter the crushing and classifying tank 5 through the feed pipes 8. Since the feed pipes 8 are evenly distributed around the outer periphery of the crushing and classifying tank 5, and their conveying paths are tangential to the inner wall of the tank, the silicon carbide raw materials are divided into multiple inlets and enter the crushing and classifying tank 5 evenly. The inner wall of the crushing and classifying tank 5 creates a spiral airflow, and the spiral patterns 51 on the inner wall, with their intersecting positive and negative threads 511 and 512, increase the thread density within the same area. This effectively increases the additional collision surface of the silicon carbide raw materials entering the crushing and classifying tank 5, further enhancing the collision efficiency of the silicon carbide raw materials. The probability of collisions between silicon carbide raw materials to be classified and between the silicon carbide raw materials to be classified and the inner wall of the crushing and classifying tank 5 is increased to ensure the crushing efficiency inside the crushing and classifying tank 5. This allows the silicon carbide raw materials to be classified to be further crushed through the above two collisions. The spiral motion of the high-temperature steam entering the crushing and classifying tank 5 generates centrifugal force inside the crushing and classifying tank 5, which throws out the silicon carbide raw materials with larger particle sizes to collide with the spiral pattern on the inner wall of the crushing and classifying tank 5, further improving the collision effect of the silicon carbide raw materials. While ensuring the crushing efficiency inside the crushing and classifying tank 5, the centrifugal force generated by the spiral motion of the high-temperature steam inside the crushing and classifying tank 5 can classify silicon carbide raw materials of different particle sizes. The silicon carbide raw materials with smaller particle sizes can move upward inside the crushing and classifying tank 5 with the high-temperature steam and be transported into the multi-layer classifying tank 6 for further classification.

[0046] High-temperature steam carries silicon carbide raw materials into the multi-layer classifier 6, generating a spiraling upward airflow. Under the action of this spiraling upward airflow, the silicon carbide particles are separated by centrifugal force. Larger silicon carbide particles are distributed in the outer layer of the spiraling upward airflow, while smaller silicon carbide particles are distributed in the inner layer. As the maximum inner diameter of the classification zones 61 decreases sequentially from bottom to top, larger silicon carbide particles are first intercepted by the lower classification zone 61, while smaller silicon carbide particles continue upward. Silicon carbide particles of different sizes are sequentially intercepted and classified by each classification zone 61. Finally, the uninterrupted silicon carbide particles enter the collection pipe 65 inside the collecting impeller 63 through the gaps between the impellers 63, which are continuously rotating under the drive motor 64. The silicon carbide particles intercepted at 61 slide down along each sub-channel 621 and converge into the main channel 622. Finally, they enter the corresponding collection tank 7 through the classification opening 623 at the bottom of the main channel 622. In actual use, the collection tank 7 is additionally equipped with a negative pressure mechanism, which is a common negative pressure machine that can provide a certain negative pressure without affecting the airflow inside the multi-layer classification tank 6, to assist the classified silicon carbide in entering the collection tank 7. The output from the collection pipe 65 includes the lowest particle size silicon carbide particles and high-temperature steam. After sedimentation treatment (in actual use, a bag filter is used to separate the silicon carbide particles and high-temperature steam, and the high-temperature steam is recovered and reused), the lowest particle size silicon carbide raw material enters a collection tank 7 for collection, completing the classification of silicon carbide.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stable submicron silicon carbide classification device, characterized by, The utility model provides a kind of carbonization silicon grading device, including: Fixed rack (1), raw material storage tank (2) are sequentially fixed with inside fixed rack (1), steam feeder (3), crushing classification tank (5), multilayer classification tank (6) and several collection tanks (7); Several feed pipes (8) are arranged between the raw material storage tank (2), the steam feeder (3) and the crushing classification tank (5), the feed pipe (8) is used to be connected between the raw material storage tank (2), the steam feeder (3) and the crushing classification tank (5) respectively, and the high-temperature steam provided by the steam feeder (3) is wrapped in the silicon carbide raw material to be classified provided by the raw material storage tank (2) and enters the crushing classification tank (5) through the feed pipe (8); Each feed pipe (8) is uniformly distributed in the outer periphery of the crushing classification tank (5), and the conveying path of each feed pipe (8) is tangent to the inner wall of the crushing classification tank (5); the crushing classification tank (5) is provided with a spiral thread (51) inside, and the spiral thread (51) is used to provide an additional collision surface for the silicon carbide raw material to be classified entering the inside of the crushing classification tank (5); The high-temperature steam provided by the steam feeder (3) generates a centrifugal effect inside the crushing classification tank (5), and the silicon carbide raw material with smaller particle size in the crushing classification tank (5) is conveyed upward into the multilayer classification tank (6), and the silicon carbide raw material with larger particle size still stays in the crushing classification tank (5) to continue to collide and crush; The multilayer classification tank (6) includes several classification zones (61), and the maximum inner diameter of the several classification zones (61) decreases from bottom to top; under the centrifugal effect generated by the spiral upward movement of the high-temperature steam, the silicon carbide raw material entering the multilayer classification tank (6) is deposited and separated on the inner wall of the multilayer classification tank (6) in each classification zone (61), and is collected into each collection tank (7) from each classification zone (61); The feed pipe (8) includes a feed branch pipe (81), an air inlet pipe (82) and a mixing pipe (83), the number of the feed pipe (8) is even, and the conveying directions of the mixing pipes (83) of the adjacent two feed pipes (8) are opposite to each other; The spiral thread (51) includes a positive thread (511) and a negative thread (512), the pitches of the positive thread (511) and the negative thread (512) are equal, the positive thread (511) and the negative thread (512) are arranged in an intersecting manner, and the thread directions of the positive thread (511) and the negative thread (512) are opposite to each other.

2. A stable sub-micron silicon carbide classification device according to claim 1, wherein: One end of the feed branch pipe (81) is in communication with the raw material storage tank (2), and the other end of the feed branch pipe (81) is in communication with one side surface of the air inlet pipe (82) close to one end of the mixing pipe (83); The air inlet pipe (82) is in communication with the steam feeder (3) and the mixing pipe (83) at two ends, respectively, and one end of the mixing pipe (83) away from the air inlet pipe (82) is in communication with the crushing classification tank (5).

3. A stable sub-micron silicon carbide classification device according to claim 2, wherein: The length of the gas inlet pipe (82) and the mixing pipe (83) of each feeding pipe (8) is equal. Each two adjacent feeding pipes (8) form a pair of pipe groups, and the conveying directions of the two mixing pipes (83) in one pipe group are symmetrical, and the conveying directions of the two mixing pipes (83) are the same.

4. A stable sub-micron silicon carbide classification device according to claim 2, wherein: The steam supplier (3) comprises a connecting pipe, a filter, a temperature regulator and a speed regulator which are sequentially connected, the connecting pipe is used for communicating with a steam generator to obtain high-temperature steam, the filter is used for filtering impurities in the high-temperature steam and adsorbing excess moisture in the high-temperature steam, the temperature regulator is used for re-heating the high-temperature steam to maintain the temperature of the high-temperature steam, and the speed regulator is used for adjusting the flow rate of the high-temperature steam entering the gas inlet pipe (82) of each feeding pipe (8).

5. A stable sub-micron silicon carbide classification device according to claim 4, wherein: The quantitative valve (21) is arranged at the connection between the raw material storage tank (2) and the feeding branch pipe (81) of each feeding pipe (8), the opening time of each quantitative valve (21) and the amount of silicon carbide raw material passing through each opening time are equal. In the same time period, the amount of silicon carbide raw material in each feeding pipe (8) is equal, and the flow rate of high-temperature steam in each feeding pipe (8) is equal.

6. A stable sub-micron silicon carbide classification device according to claim 1, wherein: The inner surface of the multi-layer grading tank (6) and the inside of each grading area (61) are provided with a collection flow channel (62), and the top of the multi-layer grading tank (6) is provided with a collection impeller (63). The multi-layer grading tank (6) can divide the silicon carbide raw material entering the inside of the multi-layer grading tank (6) into n+1 levels according to the number n of the grading areas (61), and each level of silicon carbide raw material is collected through a plurality of collection flow channels (62) and collection impellers (63) and then enters each collection tank (7).

7. A stable sub-micron silicon carbide classification device according to claim 6, wherein: The collection flow channel (62) comprises a plurality of sub-flow channels (621) and a main flow channel (622), the inclination angle of the sub-flow channel (621) is greater than that of the main flow channel (622), a grading opening (623) is arranged at the bottom of the main flow channel (622), and each grading opening (623) is connected with each collection tank (7) through a pipeline. In one grading area (61), under the action of gravity, the silicon carbide raw material collected from each sub-flow channel (621) is collected into the main flow channel (622) and then enters the corresponding collection tank (7) through the grading opening (623).

8. A stable sub-micron silicon carbide classification device according to claim 6, wherein: The collection impeller (63) is provided with a driving motor (64) on one side, the collection impeller (63) rotates under the action of the driving motor (64), the collection impeller (63) is provided with a direction away from the side of the driving motor (64) in the center and penetrates through the collection pipe (65) of the multi-layer grading tank (6). The high-temperature steam carries the smallest-size silicon carbide raw material spirally upwards inside the multi-layer grading tank (6) until it passes through the rotating collecting impeller (63) into the collecting pipeline (65) arranged in the center of the collecting impeller (63), and after the settlement treatment, the smallest-size silicon carbide raw material is collected inside a collecting tank (7).

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