A granular silicon gas suspension dynamic sorting device and sorting system

Abstract

The utility model provides a kind of granular silicon gas suspension dynamic sorting device and sorting system, it is related to polysilicon field;Sorting system includes transport track, recovery bin, purging dust removal device and granular silicon gas suspension dynamic sorting device;Granular silicon gas suspension dynamic sorting device includes closed sorting cavity, sorting cavity is inverted conical structure, its top side is provided with granular silicon inlet, its side wall upper portion away from granular silicon inlet is provided with fan;Sorting cavity bottom is sequentially provided with multiple granular collection box along airflow direction;Multiple granular collection box is respectively used to collect granular silicon of different particle size;Multiple guide plates, multiple guide plates are one-to-one corresponding and set in the side of multiple granular collection box away from granular silicon inlet, and the height of multiple guide plates is sequentially increased along airflow direction.This application can accurately distinguish granular silicon of different particle size and sorting and collection, and sorting precision is high;And dust removal rate is significantly improved, to avoid sorting misjudgment and subsequent process pollution.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline silicon, and more specifically, to a dynamic separation device and system for particulate silicon air suspension. Background Technology

[0002] With the increasing demand for high-purity polysilicon raw materials from the semiconductor industry, granular silicon has gradually become one of the mainstream raw materials due to its good flowability and feeding efficiency.

[0003] In the production and application of granular silicon, in order to meet diverse production needs such as optimizing the mixing ratio of granular silicon and rod-shaped silicon, it is necessary to sort the granular silicon according to characteristics such as particle size.

[0004] Traditionally, vibrating screens are used to sort granular silicon, but these devices have low sorting accuracy and cannot accurately distinguish granular silicon of different sizes, resulting in granular silicon particles of varying sizes after sorting. In addition, micron-sized dust easily adheres to the surface of granular silicon, and traditional blowing devices have low dust removal efficiency. Dust residue can lead to misjudgment in sorting and contamination in subsequent semiconductor processes. Utility Model Content

[0005] The purpose of this invention is to provide a dynamic separation device and system for particulate silicon air suspension, which can accurately distinguish and separate and collect particulate silicon of different sizes, thereby improving separation accuracy and efficiency.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A dynamic separation device for particulate silica suspended in gas includes: A closed sorting chamber has an inverted conical structure with a silicon particle inlet on one side of its top. An air inlet and an air outlet are provided on the side wall of the sorting chamber, and the air inlet and the air outlet are arranged opposite to each other. Multiple particle collection boxes are arranged sequentially at the bottom of the sorting chamber along the airflow direction. The multiple particle collection boxes are used to collect silicon particles of different sizes. A guide plate is provided between two adjacent particle collection boxes. The guide plate is positioned facing the wind, and the height of the multiple guide plates increases sequentially along the airflow direction.

[0007] Furthermore, each of the particle collection boxes is provided with an abnormal material collection box on the side near the air inlet; The guide plate has multiple sieve holes; the diameter of the sieve holes is smaller than the particle size of the silicon particles to be collected in the corresponding particle collection box; each guide plate has a baffle on its leeward side, which is used to separate the abnormal material collection box from the upper part of the adjacent particle collection box.

[0008] Furthermore, the upper end of the guide plate is inclined away from the air inlet.

[0009] Furthermore, the height of the plurality of baffles increases sequentially along the airflow direction.

[0010] Furthermore, an electrostatic dust removal mechanism is provided inside the sorting chamber, the electrostatic dust removal mechanism including an electrode plate and a discharge needle; the electrode plate is disposed on the inner wall of the sorting chamber, and the discharge needle is disposed at the center of the top of the sorting chamber.

[0011] Furthermore, the sorting cavity is an inverted cone shape, with a bottom diameter of 50-150cm and a top diameter of 200-300cm.

[0012] A particulate silicon sorting system includes a transport track, a recovery hopper, a dust removal and purging device, and the particulate silicon air suspension dynamic sorting device. The beginning of the transport track is connected to the outlet of a fluidized bed reactor, and the end of the transport track is connected to the inlet of the particulate silicon. The transport track has several through holes. The recovery hopper is located below the transport track, and the dust removal and purging device is arranged relative to the transport surface of the transport track.

[0013] Furthermore, the dust removal device includes a blowing mechanism and a negative pressure mechanism, wherein the blowing mechanism is disposed above the transport track and the negative pressure mechanism is disposed below the transport track.

[0014] Furthermore, the transport track is arranged in a wave-like shape.

[0015] This utility model has at least the following advantages or beneficial effects: This invention features a closed, inverted conical sorting chamber with a silicon particle inlet at the top and a fan at the outlet on the upper side of the sidewall away from the inlet. This creates an airflow from the silicon particle inlet to the opposite side within the sorting chamber. The inverted conical structure results in varying airflow velocities at different heights, creating a natural gradient in the airflow provided by the fan. Multiple particle collection boxes at the bottom of the sorting chamber, arranged along the airflow direction, collect silicon particles of varying sizes. Combined with multiple guide plates whose height increases along the airflow direction, precise sorting is achieved based on the balance between silicon particles of different sizes and aerodynamic forces, significantly improving sorting accuracy compared to traditional vibrating screening methods. Attached Figure Description

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

[0017] Figure 1 A schematic diagram of the overall structure of the dynamic separation device for particulate silicon gas suspension provided in the embodiment of the application; Figure 2 A schematic diagram of the guide plate provided in the embodiment of the application; Figure 3 A schematic diagram of the sorting system provided in the application embodiment; Figure 4 A schematic diagram of the transport track provided in the application embodiment.

[0018] Reference numerals: 1-Separation chamber, 11-Particle silicon inlet, 21-Large particle collection box, 22-Uniform particle collection box, 23-Small particle collection box, 3-Fan, 4-Guide plate, 41-Sieve hole, 5-Abnormal material collection box, 6-Baffle, 7-Fine powder collection box, 8-Transport track, 81-Through hole, 9-Fluidized bed reactor. Detailed Implementation

[0019] Example

[0020] Please refer to Figures 1-2 The figure shown is a schematic diagram of the dynamic separation device for particulate silicon gas suspension in an embodiment of this utility model.

[0021] This embodiment provides a dynamic separation device for particulate silicon air suspension, including a closed separation chamber 1. A particulate silicon inlet 11 is located on one side of the top of the chamber, through which particulate silicon falls into the separation chamber 1. An air inlet is located opposite the air outlet. A fan 3 can be located at either the air inlet or the air outlet. When located at the air outlet, it acts as a negative pressure fan, providing stable airflow power for the entire separation chamber 1. The separation chamber 1 has an inverted conical structure. Due to the gradually increasing cross-sectional area from bottom to top, the airflow provided by the fan 3 forms a natural gradient, i.e., high wind speed at the bottom and low wind speed at the top. This gradient airflow provides the basic conditions for separating particulate silicon of different sizes. Large-diameter particulate silicon, due to its greater gravity, is difficult to lift under the influence of the higher wind speed at the bottom and will move along the bottom; while small-diameter particulate silicon, with its lower gravity, can be carried upwards by the lower wind speed at the top.

[0022] Multiple particle collection boxes are arranged sequentially along the airflow direction at the bottom of the sorting chamber 1, adapting to the airflow gradient to accurately collect silicon particles of different sizes. Guide plates 4 are positioned between adjacent particle collection boxes, facing the airflow, with their heights increasing sequentially along the airflow direction. This design of progressively increasing height further optimizes the sorting effect. The lower guide plates 4 correspond to the high-speed area at the bottom, guiding larger silicon particles moving in that area smoothly into their respective collection boxes; while the higher guide plates 4 correspond to the low-speed area above, guiding smaller silicon particles carried by the airflow into their corresponding collection boxes. This structural combination allows silicon particles of different sizes to be guided to their corresponding collection boxes within their respective suitable airflow areas, significantly improving sorting accuracy, far superior to traditional vibrating screening methods.

[0023] In addition, the enclosed sorting chamber 1 structure avoids interference from the external environment on the sorting process, reduces the mixing of dust and other impurities, and also prevents the leakage of particulate silicon and dust during the sorting process, which not only ensures the purity of the sorting, but also facilitates subsequent dust removal.

[0024] As an example, the aforementioned fan 3 can be a variable frequency fan. The variable frequency fan is precisely controlled by a PLC control system, which adjusts the fan speed in real time according to the characteristics of the granular silicon and the sorting requirements, thereby controlling the airflow speed and pressure.

[0025] As an example, the bottom of the sorting chamber 1 is also provided with multiple abnormal material collection boxes 5, which are arranged adjacent to each other in front of multiple particle collection boxes; the guide plate 4 has multiple sieve holes 41; the aperture of the sieve holes 41 is smaller than the particle size of the silicon particles to be collected in the corresponding particle collection box 2. By setting multiple abnormal material collection boxes 5 and setting sieve holes 41 on the guide plate 4, silicon particles that do not belong to the collection range of the particle collection box 2 can enter the corresponding abnormal material collection box 5 under the action of airflow.

[0026] Furthermore, the aforementioned sieve holes 41 are horizontally or vertically arranged strip-shaped holes. The cooperation between the horizontally or vertically arranged strip-shaped sieve holes 41 and the abnormal material collection box 5 forms a dual guarantee of precise interception and efficient diversion. On the one hand, the aperture of the strip-shaped sieve holes 41 is smaller than the particle size of the particles to be collected in the corresponding particle collection box 2, which can effectively intercept qualified silicon particles and ensure that qualified materials accurately enter the target collection box. On the other hand, its horizontally extended shape increases the effective separation area of ​​the sieve holes 41, making it easier to capture particles with abnormal size or irregular shape compared to circular holes. This allows these abnormal particles to pass smoothly through the sieve holes 41 and fall into the adjacent abnormal material collection box 5, avoiding them from mixing with qualified materials and causing misjudgment in sorting. At the same time, the horizontal strip-shaped hole structure can also reduce the probability of dust accumulation in the holes, avoid clogging the sieve holes 41, and can be carried into the fine powder collection box 7 behind by the airflow.

[0027] As an example, the upper end of the guide plate 4 is inclined away from the air inlet, which facilitates the sliding of silicon particles into the corresponding collection box along the plate, improving collection efficiency. Multiple baffles 6 are also provided inside the sorting chamber 1. These baffles 6 are arranged at intervals behind the guide plates 4 along the airflow direction, with their heights increasing sequentially and lower than the height of their front guide plates 4. The baffles 6 are located on the side of the corresponding abnormal material collection box 5 near the outlet airflow. The rear baffles 6 can further intercept abnormal particles falling through the screen holes 41, preventing them from entering the next stage collection box with the airflow, ensuring that abnormal material stably enters the abnormal material collection box 5, and enhancing sorting reliability.

[0028] As an example, a fine powder collection box 7 is also provided at the bottom of the sorting chamber 1. The fine powder collection box 7 is located on the side of the multiple particle collection boxes 2 away from the particle silicon inlet 11. The fine powder collection box 7 is located at the end of the particle collection box 2, which can collect the dust that is separated during the sorting process, prevent the dust from adhering to the surface of qualified particles or mixing into the collection box, improve dust removal efficiency, and ensure the cleanliness of subsequent semiconductor processes.

[0029] Furthermore, the aforementioned particle collection box 2, fine powder collection box 7, and abnormal material collection box 5 can be detachably installed at the bottom of the sorting chamber 1, such as by magnetic attraction or snap-fit, to facilitate material retrieval.

[0030] As an example, the above-mentioned particle collection box is provided with four boxes, namely a large particle collection box 21, a uniform particle collection box 22, a small particle collection box 23, and a fine powder collection box 7. The large particle collection box 21, the uniform particle collection box 22, the small particle collection box 23, and the fine powder collection box 7 are arranged in sequence along the airflow direction.

[0031] Specifically, silicon particles with a diameter > 500 μm are considered large particles. The bottom of the air suspension sorting chamber 1 is a high-speed zone (6-10 m / s). When gravity > aerodynamic force, the heavy particles are pushed down along the guide plate 4 to the large particle collection box 21. Silicon particles with a diameter of 200-500 μm are considered uniform silicon particles. The middle sorting zone (speed 4-6 m / s) allows the 200-500 μm particles to suspend and sink along the guide plate 4 to the uniform particle collection box 22 when the aerodynamic force is balanced. Silicon particles with a diameter less than 200 μm and greater than 50 μm are considered small silicon particles. The top low-speed zone (2-4 m / s) allows the small silicon particles (50-200 μm) to enter the small particle collection box 23 along the guide plate 4 as seed crystals for later use.

[0032] The first three collection boxes are specifically designed to collect silicon particles >500μm, 200-500μm, and 50-200μm, respectively, which can meet diverse production needs such as optimizing the mixing ratio of silicon particles and rod-shaped silicon. The graded collection allows for precise classification of particles of different sizes, facilitating differentiated processing in subsequent processes.

[0033] As an example, the sorting chamber 1 is equipped with an electrostatic dust removal mechanism, which includes an electrode plate and a discharge needle. The electrode plate is disposed on the inner wall of the sorting chamber 1, and the discharge needle is disposed at the center of the top of the sorting chamber 1. The radial electrostatic field formed by the electrode plate and the discharge needle causes charged dust particles on the surface of the silicon particles to move towards the electrode plate and be adsorbed by electrostatic force. This achieves deep dust removal while performing air suspension sorting, solving the problem of incomplete dust removal by traditional blowing devices, significantly improving the dust removal rate, and avoiding sorting errors and process contamination caused by dust residue.

[0034] As an example, the sorting chamber 1 described above is conical in shape, with a bottom diameter of 50-150 cm and a top diameter of 200-300 cm. This ensures a stable airflow gradient within the inverted conical structure, providing a suitable airflow environment for the sorting of particles of different sizes and guaranteeing the stability and efficiency of the sorting process. In other embodiments, it can also be an inverted square pyramid shape.

[0035] The guide plate 4 has arc-shaped connecting parts on its opposite sides that fit against the inner wall of the sorting chamber 1, which effectively block silicon particles of different sizes to achieve more precise and efficient sorting.

[0036] The electrode plates are arranged in a ring on the inner wall of the sorting chamber 1 to increase the contact area with dust and effectively adsorb dust.

[0037] Reference Figures 3-4This application also provides a particulate silicon sorting system, including a transport track 8, a recovery hopper, a dust removal and purging device, and the aforementioned particulate silicon air suspension dynamic sorting device. The beginning of the transport track 8 is connected to the outlet of the fluidized bed reactor 9, and the end of the transport track 8 is connected to the particulate silicon inlet 11, realizing continuous online processing of particulate silicon. The transport track 8 has several through holes 81. The recovery hopper is located below the transport track 8, and the dust removal and purging device is positioned relative to the transport surface of the transport track 8. The through holes 81 of the track cooperate with the dust removal and purging device so that when particulate silicon passes through, dust falls off and falls into the recovery hopper.

[0038] As an example, the aforementioned dust removal device includes a blowing mechanism and a negative pressure mechanism. The blowing mechanism is positioned above the transport track 8, and the negative pressure mechanism is positioned below the transport track 8. The upper blowing mechanism actively blows the surface of the silicon particles, causing the attached dust to fall off. The negative pressure airflow forms suction through the through-hole 81, drawing the dust into the lower recycling bin. This combination creates an upward blowing and downward suction pre-dust removal mode, enhancing the pre-dust removal effect, reducing the amount of dust entering the sorting chamber 1, and lowering the dust removal load of the sorting chamber 1. By pre-adsorbing dust before sorting, and simultaneously allowing tiny particles <50μm to fall into the recycling bin as seed crystals, the subsequent sorting accuracy is improved, raw material utilization is increased, and waste is reduced.

[0039] It should be noted that the aforementioned negative pressure mechanism can be formed by a fan and a negative pressure hood installed below the transport track 8; the aforementioned purging mechanism can be a purging fan installed above the transport track 8, or a hood can be installed above it to improve the purging effect and prevent dust from escaping.

[0040] As an example, the aforementioned transport track 8 is arranged in a wave shape. The wave-shaped transport track 8 causes the silicon particles to tumble and rub against each other during transport, making it easier for surface dust to fall off. At the same time, the wave motion increases the probability of tiny particles falling through the through holes 81, improving the efficiency of pre-dust removal and preliminary sorting, and laying the foundation for subsequent precise sorting.

[0041] It should be noted that the aforementioned wavy transport track 8 can be formed by multiple conveyor rollers and conveyor belts arranged at different heights. The through hole 81 is set on the transmission belt. Its transmission principle is existing technology and will not be described in detail in the embodiments of this application.

[0042] In one specific embodiment, when particulate silicon flows into the conveyor track through the outlet of fluidized bed reactor 9: Pre-dust removal stage: The dust removal device is turned on and started at the same time. The negative pressure airflow (10-15m / s) under the track draws the dust into the recovery hopper through the through hole 81. Conveying and preliminary sorting: Particle silicon moves along the wave-shaped transport track 8. Tiny particles (<50μm) fall into the recycling bin through the groove holes, while the remaining particles enter the air suspension sorting device. Main dust removal and sorting stage: The bottom of the air suspension sorting chamber 1 is a high-velocity zone with a wind speed of 8 m / s, which pushes heavy particles (>500 μm) down along the guide plate 4 to the large particle collection box 21; the middle sorting zone has a wind speed of 5 m / s, which suspends 200-500 μm particles and causes them to settle down along the guide plate 4 to the uniform particle collection box 22, while the electrostatic field in the chamber adsorbs charged dust; the top low-velocity zone has a wind speed of 3 m / s, which causes small silicon particles (50-200 μm) to enter the small particle collection box 23 along the guide plate 4, while the dust is captured by the electrode plate; Packaging stage: qualified particles are weighed and then packaged as pure material or mixed material. Unqualified particles and dust are processed through rejection channels and dust collection bins respectively. The PLC system records sorting data in real time, which can be traced back to the upstream process.

[0043] The beneficial effects of the embodiments of this application are as follows: An airflow gradient is created through the inverted conical sorting chamber 1. Combined with three-stage guide plates 4 and a PLC-controlled variable frequency fan, granular silicon of different sizes can be accurately separated, with a precision far superior to traditional vibrating screening methods. Pre-dust removal is achieved through structures such as purging, negative pressure, and a corrugated track; primary dust removal is achieved through air suspension and electrostatic field. This two-stage composite dust removal mode significantly improves dust removal efficiency, avoiding sorting misjudgments and subsequent process contamination. The PLC system controls airflow speed and electrostatic field parameters to adapt to granular silicon of different sizes and surface conditions, meeting diverse production needs. The system is directly connected to the fluidized bed reactor 9, enabling online processing of granular silicon from discharge to sorting, dust removal, and collection, thus improving production efficiency.

[0044] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A dynamic separation device for particulate silica gas suspension, characterized in that, include: A closed sorting chamber has an inverted conical structure with a silicon particle inlet on one side of its top. An air inlet and an air outlet are provided on the side wall of the sorting chamber, and the air inlet and the air outlet are arranged opposite to each other. Multiple particle collection boxes are arranged sequentially at the bottom of the sorting chamber along the airflow direction. A guide plate is provided between two adjacent particle collection boxes. The guide plate is positioned facing the wind, and the height of the multiple guide plates increases sequentially along the airflow direction.

2. The particulate silica gas suspension dynamic sorting device according to claim 1, characterized in that, Each of the aforementioned particle collection boxes is equipped with an abnormal material collection box on the side near the air inlet; The guide plate has multiple sieve holes; the diameter of the sieve holes is smaller than the particle size of the silicon particles to be collected in the corresponding particle collection box; each guide plate has a baffle on its leeward side, which is used to separate the abnormal material collection box from the upper part of the adjacent particle collection box.

3. The particulate silica gas suspension dynamic sorting device according to claim 2, characterized in that, The upper end of the guide plate is inclined away from the air inlet.

4. The particulate silica gas suspension dynamic sorting device according to claim 2, characterized in that, The height of the multiple baffles increases sequentially along the airflow direction.

5. The particulate silica gas suspension dynamic sorting device according to claim 1, characterized in that, An electrostatic dust removal mechanism is provided inside the sorting chamber. The electrostatic dust removal mechanism includes an electrode plate and a discharge needle. The electrode plate is disposed on the inner wall of the sorting chamber, and the discharge needle is disposed at the center of the top of the sorting chamber.

6. The particulate silica gas suspension dynamic sorting device according to claim 1, characterized in that, The sorting cavity is an inverted cone shape, with a bottom diameter of 50-150cm and a top diameter of 200-300cm.

7. A particulate silicon sorting system, characterized in that, The device includes a transport track, a recycling bin, a dust removal and purging device, and a particulate silicon gas suspension dynamic sorting device as described in any one of claims 1-6. The beginning of the transport track is connected to the outlet of the fluidized bed reactor, and the end of the transport track is connected to the inlet of the particulate silicon. The transport track has several through holes. The recycling bin is located below the transport track, and the dust removal and purging device is arranged relative to the transport surface of the transport track.

8. The sorting system according to claim 7, characterized in that, The dust removal device includes a blowing mechanism and a negative pressure mechanism. The blowing mechanism is located above the transport track, and the negative pressure mechanism is located below the transport track.

9. The sorting system according to claim 7, characterized in that, The transport track is designed in a wave-like shape.

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