Granular material screening device and granular material screening method

Abstract

The invention provides a granule screening device and a granule screening method. The granule screening device comprises a screening barrel and a supporting frame. Wherein the screening barrel comprises an inlet ring, an outlet ring and a plurality of parallel connecting rods for connecting the inlet ring and the outlet ring. A crushing bin with an upper opening is fixedly arranged on the supporting frame, the crushing bin comprises a first end and a second end which are far away from each other in the first direction, and the first end of the crushing bin is higher than the second end; at least two inlet rollers capable of rotating freely are arranged on the inner side of the first end of the material crushing bin, at least two outlet rollers capable of rotating freely are arranged on the inner side of the second end of the material crushing bin, and the inlet ring and the outlet ring are arranged on the inlet rollers and the outlet rollers in a lap joint mode respectively. According to the technical scheme, the material screening barrel is arranged in an inclined mode and can rotate, so that continuous and automatic particle material screening operation is achieved, the screening efficiency and effect are improved, and meanwhile the pollution risk is reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing, and in particular, to a granular material screening device and a granular material screening method. Background Art

[0002] In the process of single-crystal silicon production, polysilicon granular materials (usually with a diameter less than 30 mm) are one of the key raw materials, which are usually used in combination with large silicon materials to improve the stacking density of silicon materials and the total weight of the first charge. Since the existing single-crystal silicon thermal field is usually large in size, in order to improve production efficiency and reduce production costs, the polysilicon granular materials can also be recharged twice in the single-crystal furnace. However, fine dust (usually with a diameter less than 1 mm) will inevitably be generated during the processing and transportation of polysilicon granular materials. These dusts are easily scattered by the airflow during the secondary recharging process. Some of the scattered dusts will adhere to relatively low-temperature areas such as the flow guide cylinder and the quartz crucible, and fall off into the melt as the temperature drops, drifting to the growth interface, resulting in the "wire breakage" phenomenon, thereby reducing the product yield. Therefore, screening and removing the fine dust in polysilicon granular materials is crucial for ensuring the quality and efficiency of single-crystal silicon production.

[0003] In the prior art, a mesh vibrating screen is mainly used to screen out dust. This device is usually provided with a screen mesh, allowing small-particle materials to pass through the screen mesh and fall below the device, while large-particle materials remain on the screen mesh. However, this device cannot automatically transport the large-particle materials away after screening the materials, and manual removal is required, which is not only time-consuming and laborious, but also the operator's gloves are in direct contact with the silicon materials, easily introducing pollution sources such as carbon and metal. In addition, when there are more materials to be screened, it is easy to accumulate in the screen mesh. Therefore, it is difficult to fully screen the fine dust in the upper-layer materials, and the entire screening process is inefficient. In summary, there are many deficiencies in the prior art when screening polysilicon granular materials, and it is difficult to meet the production requirements of high efficiency, cleanliness, and low pollution. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a granular material screening device and a granular material screening method. The screening cylinder of the granular material screening device is placed in an inclined manner and can rotate, thereby realizing continuous and automatic granular material screening operations, improving the screening efficiency and effect, and reducing the pollution risk at the same time.

[0005] In a first aspect, the present application provides a granular material screening device, which includes a screening cylinder and a support frame. Among them, the screening cylinder includes an inlet ring, an outlet ring, and a plurality of parallel connecting rods connecting the inlet ring and the outlet ring. A crushing bin with an upper opening is fixedly arranged on the support frame. The crushing bin includes a first end and a second end that are far away from each other in a first direction. The first end of the crushing bin is higher than the second end; at least two freely rotatable inlet rollers are arranged inside the first end of the crushing bin, and at least two freely rotatable outlet rollers are arranged inside the second end of the crushing bin. The inlet ring and the outlet ring are respectively placed on the inlet rollers and the outlet rollers.

[0006] In an implementable solution, a driving gear is arranged outside the first end and / or the second end of the crushing bin. A driven gear meshing with the driving gear is arranged on the end face of the inlet ring, and / or a driven gear meshing with the driving gear is arranged on the end face of the outlet ring.

[0007] In an implementable solution, a plurality of through holes are uniformly arranged along the circumferential direction on the end faces of the inlet ring and the outlet ring respectively, and both ends of the connecting rod are respectively installed in the corresponding through holes of the inlet ring and the outlet ring.

[0008] In an implementable solution, a discharge hopper is fixedly arranged outside the second end of the crushing bin, which is used to guide the screened material into a preset position.

[0009] In an implementable solution, the support frame includes a plurality of support rods that can freely adjust their heights within a preset range.

[0010] In an implementable solution, air extraction holes are arranged on the surface of the crushing bin, which are used to extract air from the crushing bin to form a negative pressure space inside the crushing bin.

[0011] In an implementable solution, the granular material screening device further includes a driver, which is power-connected to the driving gear and is used to drive the screening cylinder to rotate around its own center line.

[0012] In an implementable solution, the connecting rod of the screening cylinder is made of quartz material.

[0013] In an implementable solution, the inlet ring, the outlet ring, the inlet rollers, the outlet rollers, and the crushing bin are made of PEEK-based materials.

[0014] In a second aspect, the present application also provides a granular material screening method, which uses the granular material screening device and includes the following steps:

[0015] S1. According to the screening size of the target material, adjust the connecting rod gap of the screening cylinder and the rotation speed of the screening cylinder;

[0016] S2. Start the rotation of the screening cylinder, and then pour the material to be screened into the inlet ring of the screening cylinder.

[0017] S3. The material to be screened moves towards the outlet ring of the screening cylinder under the action of gravity. During the movement, the materials with sizes smaller than the preset screening standard automatically fall into the crushing bin, and the remaining materials leave the screening cylinder through the outlet ring.

[0018] S4. Inspect the screened materials. If the proportion of the materials with sizes smaller than the screening size of the target material is higher than the preset standard, the screening process is unqualified. At this time, take measures such as increasing the rotation speed of the screening cylinder and / or increasing the length of the connecting rod, and then repeat steps S2 - S4 until the screening process is qualified.

[0019] Compared with the prior art, the beneficial effects of the present application at least include:

[0020] The present application provides a granular material screening device, the screening cylinder of which is placed in an inclined manner. Therefore, compared with the traditional granular material screening device, after the material screening is completed, the remaining large - granular materials of the granular material screening device of the present application will automatically leave the screening cylinder through the outlet ring without manual removal. On the one hand, it reduces the pollution risk introduced by manual operation, and on the other hand, it can realize continuous operation, effectively reducing the time cost and improving the screening efficiency. In addition, since the screening cylinder can rotate around its own central axis, the materials will continuously roll laterally during the process of passing through the screening cylinder and will not pile up together, ensuring that all materials can fully contact the side wall of the screening cylinder. Therefore, it can better ensure that the small - granular materials among them can be fully screened out. Further, the support frame of the granular material screening device of the present application is provided with a plurality of support rods with adjustable heights, which can adjust the inclination degree of the screening cylinder, so as to adapt to different actual needs and improve the efficiency and effect of granular material screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of the granular material screening device shown according to the embodiment of the present application;

[0023] Figure 2 It is an exploded schematic diagram of the screening cylinder;

[0024] Figure 3 It is a schematic diagram of the support frame;

[0025] Figure 4 It is a schematic flow chart of the granular material screening method shown according to the embodiment of the present application.

[0026] In the figure: 1. Screening material cylinder; 2. Support frame; 3. Crushing bin; 101. Inlet ring; 102. Outlet ring; 103. Connecting rod; 104. Driven gear; 105. Through hole; 201. Support rod; 301. Inlet roller; 302. Outlet roller; 303. Driving gear; 304. Feeding hopper; 305. Air extraction hole. Specific embodiments

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but is merely representative of selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0029] As Figure 1 shown, the present application provides a granular material screening device, including a screening material cylinder 1 and a support frame 2. Among them, the screening material cylinder 1 includes an inlet ring 101, an outlet ring 102, and a plurality of parallel connecting rods 103 connecting the inlet ring 101 and the outlet ring 102. A crushing bin 3 with an upper opening is fixedly arranged on the support frame 2 for accommodating small granular materials falling from the screening material cylinder 1. The crushing bin 3 includes a first end and a second end that are spaced apart from each other along the first direction L1, wherein the first end of the crushing bin 3 is higher than the second end, so that the inlet ring 101 of the screening material cylinder 1 is higher than the outlet ring 102. Preferably, the central axis of the screening material cylinder 1 can form an angle of 20-45 degrees with the horizontal plane, so that the granular silicon can automatically move towards the outlet under the action of gravity in the screening material cylinder while maintaining a good screening effect. Specifically, support rods 201 with different lengths can be provided for the support frame 2 and the crushing bin 3 can be fixedly connected to the tops of the respective support rods 201, so that the first end of the crushing bin 3 is higher than the second end.

[0030] As Figure 3As shown, at least two freely rotatable inlet rollers 301 are provided on the inner side of the first end of the scrap bin 3, and at least two freely rotatable outlet rollers 302 are provided on the inner side of the second end of the scrap bin 3. The inlet ring 101 and the outlet ring 102 are respectively placed on the inlet rollers 301 and the outlet rollers 302. The inlet rollers 301 and the outlet rollers 302 form a stable support for the inlet ring 101 and the outlet ring 102, and when the screening cylinder 1 rotates, the inlet rollers 301 and the outlet rollers 302 rotate correspondingly with the screening cylinder 1 to keep the position of the screening cylinder 1 stable.

[0031] As Figure 2 shown, a plurality of through holes 105 can be uniformly arranged along the circumferential direction on the end faces of the inlet ring 101 and the outlet ring 102 respectively. Both ends of the connecting rod 103 are respectively installed in the corresponding through holes 105 of the inlet ring 101 and the outlet ring 102. In actual use, the installation method of the connecting rod 103 can be adjusted according to requirements. For example, if the size of the material to be screened is large, one through hole 105 can be spaced between each connecting rod 103, that is, half of the through holes 105 are left empty. In addition, multiple groups of inlet rings 101 and outlet rings 102 can be prepared in advance. Each group of inlet rings 101 and outlet rings 102 has different through hole 105 intervals and / or through hole 105 diameters, and connecting rods 103 matching the through hole 105 diameters are prepared at the same time, that is, the size of the material to be screened is determined by adjusting the distance between the connecting rods 103. Generally, the diameter of the through hole 105 can be set to 5 - 30 mm, preferably 10 - 20 mm, and the distance between adjacent through holes 105 can be set to 0.1 - 10 mm, preferably 2 - 5 mm. The inner diameters of the inlet ring 101 and the outlet ring 102 can be set to 200 - 1000 mm, preferably 300 - 500 mm.

[0032] Preferably, the connecting rod 103 of the screening cylinder 1 can be made of quartz material. Quartz material has the advantages of high purity, high hardness, and good wear resistance. It can withstand the frictional force generated during the screening of granular materials, effectively avoid introducing impurities during the screening process, ensure the purity of the screened polysilicon granular materials, and at the same time can extend the service life of the connecting rod and reduce the equipment maintenance cost. In addition, quartz material has good chemical stability and is not easy to react with polysilicon granular materials or chemical substances in the environment, ensuring the stability and reliability of the screening process. The inlet ring 101, outlet ring 102, inlet roller 301, outlet roller 302, and crushing bin 3 can be made of PEEK-based materials (PEEK-like materials include high-performance polyaryletherketone plastics such as PEEK (polyetheretherketone), PAEK (polyaryletherketone), PEK (polyetherketone), and PEKEKK (polyetherketoneetherketoneketone)). This type of material has high strength, high modulus, and good wear resistance, can withstand the mechanical stress generated during the screening process, ensure the stable operation of the equipment, and at the same time has a low friction coefficient, can reduce the friction and wear between components, improve the operation efficiency of the equipment, and reduce energy consumption. In addition, this type has good chemical tolerance and can effectively resist chemical corrosion, extending the service life of the equipment.

[0033] During use, first rotate the screening cylinder 1 at a preset speed uniformly, and then put the material to be screened into the inlet ring 101 of the screening cylinder 1. Due to the action of gravity, the material to be screened automatically moves to the lower-positioned outlet ring 102. During the movement, rotate the screening cylinder 1 around its own central axis to make the material to be screened roll continuously in the cylinder, facilitating the small-particle materials to leak out from the gaps between the connecting rods 103.

[0034] This application provides a granular material screening device. Its screening cylinder is placed in an inclined manner. Therefore, compared with traditional granular material screening devices, after the material screening is completed in the granular material screening device of this application, the remaining large-particle materials will automatically leave the screening cylinder through the outlet ring without manual removal. On the one hand, it reduces the pollution risk introduced by manual operation, and on the other hand, it can achieve continuous operation, effectively reducing the time cost and improving the screening efficiency. In addition, since the screening cylinder can rotate around its own central axis, the material will continuously roll laterally during the process of passing through the screening cylinder and will not accumulate together, ensuring that all materials can fully contact the side wall of the screening cylinder. Therefore, it can better ensure that the small-particle materials therein can be fully screened out. Further, the support frame of the granular material screening device of this application is provided with a plurality of support rods with adjustable heights, which can adjust the inclination degree of the screening cylinder to adapt to different actual needs and improve the efficiency and effect of granular material screening.

[0035] In one embodiment, as Figure 1As shown, drive gears 303 are provided on the outer side of the first end and / or the second end of the shredding bin 3. Correspondingly, driven gears 104 meshing with the drive gears 303 are provided on the end face of the inlet ring 101, and / or driven gears 104 meshing with the drive gears 303 are provided on the end face of the outlet ring 102. During use, if it is necessary to change the rotation speed of the screening cylinder 1, the rotation speed of the drive gear 303 itself can be changed, or the tooth number ratio of the drive gear 303 and the driven gear 104 can be changed. For example, with the driven gear 104 unchanged, a drive gear 303 with different tooth numbers can be replaced. If drive gears 303 are provided at both the first end and the second end of the shredding bin 3, it is preferred to connect the drive gears 303 at both ends through a transmission shaft (not shown in the figure) to achieve synchronous rotation, so that the force on the screening cylinder 1 is more uniform, avoiding uneven force caused by single-end drive, reducing the vibration and swaying of the screening cylinder 1, improving the screening effect, and reducing mechanical wear caused by inconsistent drive to extend the service life of the equipment.

[0036] In one embodiment, a magnetic device, such as a magnetic ring (not shown in the figure. If a driven gear 104 is provided on the end face of the outlet ring 102, the magnetic device can also be provided outside the driven gear 104), can be provided on the end face of the outlet ring 102. When the material leaves the screening cylinder 1 from the outlet ring 102, the magnetic device will adsorb the ferromagnetic metal impurities that may remain in the material, further reducing the possible residual metal impurities in the screened material. Preferably, the magnetic device can be made of neodymium iron boron material, ferrite material or composite magnetic material, and no further limitation is made here.

[0037] In one embodiment, as Figure 1 shown, a discharge hopper 304 is fixedly provided on the outer side of the second end of the shredding bin 3 for guiding the screened material into a preset position. The discharge hopper 304 can prevent the screened material from scattering or accumulating, improve the cleanliness and efficiency of the screening process, and at the same time enable the material to be centrally collected, facilitating subsequent transportation, storage or further processing, and improving the coherence and automation degree of the entire production process. In addition, the discharge hopper 304 can enable the material to quickly leave the screening area, reducing the exposure time of the material in the air, thereby reducing the risk of secondary pollution.

[0038] According to actual requirements, the feeding hopper 304 can also be replaced with a feeding pipeline, so that the screened materials can be directly introduced into a collection point or subsequent processing equipment at a farther distance, reducing the residence time of the materials in the screening area and further improving the screening efficiency and the continuity of the production process. In some production environments with limited space, the feeding pipeline can be flexibly arranged according to the equipment layout, avoiding the additional space that the feeding hopper 304 may occupy, and enabling the screening device to better adapt to different production site conditions. In addition, the feeding pipeline can be easily integrated with an automated production line to achieve automatic conveying and processing of materials, improving the automation level and overall efficiency of the production process.

[0039] In one embodiment, the support frame 2 includes a plurality of support rods 201 that can freely adjust their heights within a preset range. During use, by adjusting the heights of the respective support rods 201, the inclination angle of the screening cylinder 1 can be flexibly adjusted according to different screening requirements. For example, when there are more small-particle materials in the materials to be screened, the inclination angle of the screening cylinder 1 can be reduced by adjusting the heights of the support rods 201, so that the materials stay in the screening cylinder 1 for a longer time and the screening effect is more sufficient. Preferably, the two support rods 201 close to the inlet ring 101 can be set to be adjusted synchronously and linked, and the two support rods 201 close to the outlet ring 102 can be set to be adjusted synchronously and linked to prevent the screening cylinder 1 from tilting. Specifically, telescopic support rods or segmented support rods can be used as the support rods 201. Among them, the telescopic support rods achieve height adjustment through threaded, hydraulic or pneumatic devices; the segmented support rods can be composed of multiple segments, and during use, the height is adjusted by plugging or screwing. Alternatively, adjustment nuts can also be provided at the bottom or top of the support rods 201, and the height can be adjusted with higher precision by rotating the nuts.

[0040] In one embodiment, as Figure 1 shown, the surface of the crushing bin 3 is provided with air extraction holes 305 for extracting air from the crushing bin 3 to form a negative pressure space inside the crushing bin 3. After the negative pressure space is formed, fine materials can be effectively sucked out of the screening cylinder 1, improving the screening efficiency and effect, and at the same time avoiding dust flying caused by the materials falling into the crushing bin 3 and reducing pollution. Specifically, the air extraction holes 305 can be externally connected to an air extractor or an industrial vacuum cleaner, and there is no limitation here. In addition, if the size of the materials to be screened is large, a filter screen can also be provided on the air extraction holes to block larger particle materials from entering the air extraction holes 305, thereby preventing the pipeline of the air extractor or industrial vacuum cleaner from being blocked or damaged and extending the service life of the equipment.

[0041] In one embodiment, the granular material screening device further includes a driver (not shown in the figure), which is power-connected to the driving gear 303 and is used to drive the screening cylinder 1 to rotate around its own central axis. Specifically, the driver can adopt an electric motor and is connected to the driving gear 303 through an output shaft to provide stable rotational power. The selection of the motor can be determined according to the size and load requirements of the screening cylinder 1. For example, an AC motor or a DC motor can be used. In order to achieve more flexible speed adjustment, a transmission, such as a gear transmission, can be installed between the driver and the driving gear 303 to achieve a speed-changing effect and better meet different screening requirements. In addition, a torque sensor and a controller can also be equipped for the driver to ensure that the screening cylinder 1 always maintains an appropriate torque during operation and avoid speed fluctuations caused by load changes.

[0042] As Figure 4 shown, the present application also provides a method for screening granular materials. This method uses the granular material screening device to perform the following steps:

[0043] S1. According to the screening size of the target material, adjust the link clearance of the screening cylinder and the rotational speed of the screening cylinder. By adjusting the clearance between the links 103 of the screening cylinder 1, ensure that the clearance matches the target screening size. For example, if the target is to screen out granular materials smaller than 2 mm, then adjust the link clearance to about 2 mm.

[0044] S2. Start the rotation of the screening cylinder, and then pour the material to be screened into the inlet ring of the screening cylinder. During actual operation, it should wait for a period of time after starting and wait until the rotational speed of the screening cylinder is stable before pouring the material to be screened.

[0045] S3. The material to be screened moves towards the outlet ring of the screening cylinder under the action of gravity. During the movement, the materials smaller than the preset screening standard automatically fall into the crushing bin, and the remaining materials leave the screening cylinder through the outlet ring.

[0046] S4. Check the screened materials. If the proportion of the materials smaller than the screening size of the target material is higher than the preset standard, the screening process is not qualified. At this time, take measures to increase the rotational speed of the screening cylinder and / or increase the link length, and then repeat steps S2 - S4 until the screening process is qualified. In addition, auxiliary means such as changing the inclination angle of the screening cylinder can also be comprehensively used to improve the screening effect.

[0047] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A granular material screening device, characterized in that, Comprising: A screening barrel (1), including an inlet ring (101), an outlet ring (102), and a plurality of parallel connecting rods (103) connecting the inlet ring (101) and the outlet ring (102); A support frame (2), on which a crushing bin (3) with an upper opening is fixedly arranged. The crushing bin (3) includes a first end and a second end that are spaced apart from each other in a first direction, and the first end of the crushing bin (3) is higher than the second end; at least two freely rotatable inlet rollers (301) are arranged inside the first end of the crushing bin (3), and at least two freely rotatable outlet rollers (302) are arranged inside the second end of the crushing bin (3). The inlet ring (101) and the outlet ring (102) are respectively placed on the inlet rollers (301) and the outlet rollers (302).

2. The pellet screening device according to claim 1, wherein A driving gear (303) is arranged outside the first end and / or the second end of the crushing bin (3); A driven gear (104) meshing with the driving gear (303) is arranged on the end face of the inlet ring (101), and / or a driven gear (104) meshing with the driving gear (303) is arranged on the end face of the outlet ring (102).

3. The pellet screening device according to claim 1, wherein A plurality of through holes (105) are uniformly arranged along the circumferences of the end faces of the inlet ring (101) and the outlet ring (102), and both ends of the connecting rod (103) are respectively installed in the corresponding through holes (105) of the inlet ring (101) and the outlet ring (102).

4. The pellet screening device according to claim 2, wherein, A discharge hopper (304) is fixedly arranged outside the second end of the crushing bin (3) to guide the screened materials into a preset position.

5. The pellet screening device according to claim 1, wherein The support frame (2) includes a plurality of support rods (201) that can freely adjust their heights within a preset range.

6. The pellet screening device according to claim 1, wherein, Air extraction holes (305) are arranged on the surface of the crushing bin (3) to extract air from the crushing bin (3) to form a negative pressure space inside the crushing bin (3).

7. The pellet screening device according to claim 2, wherein It further includes a driver, which is power-connected to the driving gear (303) to drive the screening barrel (1) to rotate around its own center line.

8. The pellet screening device according to claim 1, characterized in that, The connecting rod (103) of the screening barrel (1) is made of quartz material.

9. The pellet screening device according to claim 1, characterized in that, The inlet ring (101), the outlet ring (102), the inlet rollers (301), the outlet rollers (302), and the crushing bin (3) are made of PEEK-like materials.

10. A method for screening granular materials, using the granular material screening device according to any one of claims 1-9, characterized in that, Comprising: S1. According to the screening size of the target material, adjust the connecting rod gap of the screening barrel and the rotation speed of the screening barrel; S2. Start the rotation of the screening barrel, and then pour the material to be screened into the inlet ring of the screening barrel; S3. The material to be screened moves towards the outlet ring of the screening barrel under the action of gravity. During the movement, the materials smaller than the preset screening standard automatically fall into the crushing bin, and the remaining materials leave the screening barrel through the outlet ring; S4. Inspect the screened materials. If the proportion of materials smaller than the screening size of the target materials is higher than the preset standard, the screening process fails. At this time, take measures to increase the rotation speed of the screening cylinder and / or increase the length of the connecting rod, and then repeat steps S2 - S4 until the screening process is qualified.

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