Granular silicon feeding device and method for single crystal furnace

Abstract

The application discloses a granular silicon feeding device for a single crystal furnace and a method thereof, which comprises a storage cavity, a lifting mechanism, a bottom supporting mechanism, a middle supporting mechanism and a guiding mechanism. The lifting mechanism is arranged through the inside of the storage cavity and can move up and down in the storage cavity. When the lifting mechanism is lifted, the bottom of the lifting mechanism is clamped with the discharge port of the storage cavity and can drive the storage cavity to move up together. When the lifting mechanism is lowered and the bottom is separated from the discharge port of the storage cavity, the silicon in the storage cavity falls into the quartz crucible below from the discharge port. The bottom of the lifting mechanism is supported above the bottom supporting mechanism. The middle supporting mechanism is arranged on the middle side wall of the storage cavity. The guiding mechanism is arranged on the top of the storage cavity and is used for limiting the lateral movement of the lifting mechanism. The device can accurately control the discharging speed by lifting and lowering the middle lifting mechanism in the storage cavity at any time, and the metal pollution accidents caused by the cone burying phenomenon can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of polycrystalline silicon preparation, specifically relating to a particle silicon feeding device and method for a single crystal furnace. Background Technology

[0002] Granular silicon is a type of granular polycrystalline silicon material. With the continuous maturation of its production technology, granular silicon has been able to meet the production needs of the photovoltaic industry in terms of both capacity and quality. Granular silicon has two main applications in practice. One is to load granular silicon into a crucible, a method with lower process difficulty, which is now gradually being promoted. Secondly, a feeding device is used to add granular silicon into the furnace. Currently, there is no dedicated granular silicon feeder, and existing block feeders can only be used. However, since many designs of the existing block feeders are not specifically designed for granular silicon, many problems arise during actual feeding. For example, the granular silicon particles are too small, causing leakage at the bottom of the feeder; during actual feeding, due to the large diameter of the existing feeder, the granular silicon descends at a relatively fast speed, making it difficult to control the feeding speed and prone to cone embedding. If the bottom support is not raised in time for a long period of time, the metal connecting rod may melt, causing metal contamination of the raw material; at the same time, the granular silicon spreads in a large annular area as it slides down the bottom support, and the volatilization of silicon powder trapped inside the granular silicon is dispersed throughout the hot field with the argon gas, negatively affecting subsequent crystal pulling; since the bottom support bears the entire weight of the feeder and the raw material, and is also impacted by the descent of the raw material during feeding, the bottom support is very prone to cracking and falling into the crucible, causing raw material contamination, and in severe cases, directly shutting down the furnace. Furthermore, due to the large base, as the material descends during feeding, the silicon particles are distributed in a ring along the conical arc surface, creating a material-free area under the cone. During subsequent material processing, the silicon particles have a central pit that melts prematurely, resulting in a volcano-like phenomenon. This causes bubbling and silicon sputtering, which can prevent crystal pulling if the sputtering is severe. This abnormality is particularly common and is a technical problem that urgently needs to be solved in the process of promoting silicon particles. Summary of the Invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide a particle silicon feeding device for single crystal furnaces, which addresses the shortcomings of the existing technology and solves the problem of silicon sputtering and bubbling during the secondary feeding process in the existing crystal pulling process.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A particle silicon feeding device for a single crystal furnace includes a storage chamber, a lifting mechanism, a bottom support mechanism, a middle support mechanism, and a guiding mechanism. The lifting mechanism is disposed throughout the storage chamber and can move up and down within the storage chamber. When the lifting mechanism is lifted, its bottom engages with the discharge port of the storage chamber, and it can drive the storage chamber to move up and down together. When the lifting mechanism is lowered, causing its bottom to separate from the discharge port of the storage chamber, the silicon material in the storage chamber falls from the discharge port into the quartz crucible below. The bottom of the lifting mechanism rests on the bottom support mechanism. The middle support mechanism is disposed on the middle side wall of the storage chamber. The guiding mechanism is disposed at the top of the storage chamber and is used to limit the lateral movement of the lifting mechanism.

[0006] Furthermore, the storage chamber is a hollow circular tube used to store granular silicon raw materials; the lower end of the storage chamber is provided with a tapered discharge port that gradually narrows from top to bottom; the bottom of the lifting mechanism is provided with a tapered base that gradually increases from top to bottom, and the tapered base is adapted to the tapered discharge port; when the tapered base separates downward from the tapered discharge port, the granular silicon raw materials in the storage chamber fall onto the tapered base along the tapered discharge port, and then spread downward along the tapered base and finally fall into the quartz crucible below.

[0007] Preferably, the inclination angle of the inner wall of the conical discharge port is 60-90°; the inclination angle of the outer wall of the conical base is 60-120°.

[0008] Specifically, the lifting mechanism includes a long connecting rod, a conical base, and a T-nut; the T-nuts are a pair, which are threaded onto the two ends of the long connecting rod respectively; the conical base has a through hole in its center, and the conical base is fitted onto the bottom end of the long connecting rod and fixed by the T-nut that passes through its central through hole.

[0009] Specifically, the bottom support mechanism includes a chassis, an angular contact single-row ball bearing, and a bottom support column; the chassis has an opening at the top and is capable of accommodating the storage cavity; the angular contact single-row ball bearing is rotatably mounted at the center of the chassis; the bottom of the bottom support column is mounted on the angular contact single-row ball bearing, and the top is used to support the tapered bottom support.

[0010] Furthermore, the top of the base support column is provided with a first groove for receiving the conical base, and the bottom is provided with a second groove for engaging the angular contact single-row ball bearing; a support column fixing screw passes through the center of the base support column, and the bottom end of the support column fixing screw is a smooth section that is movably inserted into the boss in the center of the lower chassis, so that the support column fixing screw and the base support column can rotate together on the angular contact single-row ball bearing.

[0011] Specifically, the central support mechanism includes a central guide plate, a central support plate, an extension screw, and a support plate pillar. The central guide plate has a set of latches on its inner side, which are aligned with the central flange of the storage cavity and connected by a longitudinally penetrating extension screw. The central support plate is sleeved on the outer wall of the storage cavity and located below the central guide plate, connected to the central guide plate by a set of longitudinally penetrating extension screws. The support plate pillars are sleeved on the extension screws, and their number can be increased or decreased according to the distance between the central guide plate and the central support plate. The extension screws pass sequentially from bottom to top through the central support plate, the support plate pillars, the central flange of the storage cavity, and the central guide plate, and are then fixed by fastening nuts. The central support plate has vertically hollowed-out guide grooves, and a guide gap is left between the central guide plate and the outer wall of the storage cavity.

[0012] Specifically, the guiding mechanism includes a dust cover, a guide plate, and a guide plate anti-loosening nut. The dust cover covers the top of the storage chamber and has a circular countersunk hole in its center. A set of T-shaped slots are arranged circumferentially around the circular countersunk hole. The center of the circular countersunk hole has a longitudinal through hole for the lifting mechanism to pass through. The guide plate is a right-angled triangular plate structure. The bottom right-angled side of the guide plate has a plug-in block that mates with the T-shaped slot. A set of guide plates are respectively installed on the dust cover through the plug-in block at their bottom and are fixed by the guide plate anti-loosening nut screwed into the circular countersunk hole.

[0013] Furthermore, the single-crystal furnace particle silicon feeding device also includes a top protective structure; the top protective structure includes a storage chamber protective cover and protective cover fixing screws; the storage chamber protective cover covers the top inlet of the storage chamber, and its lower edge is connected and fixed to the upper flange of the storage chamber through a set of protective cover fixing screws; a crossbeam is provided in the middle of the storage chamber protective cover, and a pair of semi-circular feeding ports for feeding are provided on both sides of the crossbeam, and a longitudinal through hole for the lifting mechanism to pass through is provided in the center of the crossbeam; a set of limiting steps is provided on the outer ring of the storage chamber protective cover, and a set of limiting grooves is provided on the outer ring of the dust cover; the dust cover covers the top of the storage chamber protective cover, and the limiting grooves are engaged with the corresponding limiting steps.

[0014] Furthermore, the present invention also provides a method for secondary feeding of granular silicon using the above-mentioned feeding device, comprising the following steps:

[0015] S1: Install and fix the bottom support mechanism on the transport vehicle, then install the storage chamber, middle support mechanism, guide mechanism and lifting mechanism in sequence, and place them on the bottom support mechanism as a whole;

[0016] S2: First remove the guide mechanism at the top of the storage chamber and load granular silicon raw material into the storage chamber; at this time, the lifting mechanism, supported by the bottom support mechanism, clamps with the discharge port of the storage chamber to block the granular silicon from falling.

[0017] S3: After the granular silicon is full, install the guiding mechanism and rotate the storage chamber on the bottom support mechanism to check and clean the entire device;

[0018] S4: Transport the entire device to the furnace platform to be fed by a transport vehicle, connect the top of the lifting mechanism to the elevator of the single crystal furnace auxiliary chamber, and use the elevator and the lifting mechanism to lift the entire feeding device containing granular silicon.

[0019] S5: Slowly lift the entire feeding device into the sub-chamber of the single crystal furnace. Use the guiding mechanism to avoid collision between the storage chamber and the lower edge of the sub-chamber. After the upper part of the feeding device enters the sub-chamber, use the middle support mechanism to guide it and avoid collision between the storage chamber and the interior of the sub-chamber.

[0020] S6: After the entire feeding device enters the sub-chamber of the single crystal furnace and is purified, the feeding device will begin to descend. Argon gas will be introduced into the top of the sub-chamber. The flow-guiding structure of the middle support mechanism will be used to avoid the problem of ash adhering to the furnace wall caused by argon gas backflow.

[0021] S7: When the feeding device descends to a suitable height, the middle support mechanism will contact the throat step above the main chamber of the single crystal furnace and will be unable to descend further, thus completing the preparation work for feeding.

[0022] S8: Lowering the lifting mechanism. At this time, the bottom of the lifting mechanism separates from the feeding port, the bottom conical feeding port of the storage chamber opens, and the granular silicon raw material in the storage chamber falls along the conical feeding port to the bottom of the lifting mechanism, and then spreads down along the bottom of the lifting mechanism and finally falls into the quartz crucible below.

[0023] Beneficial effects:

[0024] (1) The feeding device of this invention isolates the metal from the material storage chamber, and the raw material contact parts are completely wrapped with quartz and polytetrafluoroethylene high-temperature resistant material to avoid raw material contamination. The inner ring of the material storage chamber discharge port is provided with an hourglass-shaped conical discharge port, which completely matches the upper conical surface of the base, forming a tight fit between the conical surfaces, which can effectively prevent small particulate silicon particles from leaking out along the gaps. The base of the lifting mechanism adopts a conical contact surface, which changes the force direction of the base, improves its service life, and avoids furnace stagnation accidents.

[0025] (2) The bottom support mechanism of the storage chamber of the present invention is compatible with the lifting mechanism and rotation function of the middle part of the storage chamber. It can lift the entire feeding device to rotate 360 ​​degrees, so that the particle silicon feeding device can be inspected and cleaned 360 degrees, avoiding the loosening and falling of the peripheral parts of the device and the inability to clean the silicon powder in time.

[0026] (3) The dual guiding device of the head guide mechanism and the middle guide plate of the storage chamber of the present invention avoids collision with the lower edge of the auxiliary chamber, thus preventing damage to the device and improving the service life of the granular silicon feeding device. A dual design is adopted to suppress silicon powder volatilization: the head dust cover and the hourglass-shaped feeding port combined with the quartz cover change the feeding path, reduce the raw material scattering area, and reduce the volatilization of silicon powder in the raw material.

[0027] (4) The central support mechanism of the present invention is equipped with an argon gas channel to ensure that argon gas passes smoothly, avoid abnormal backflow of gas in the furnace, and reduce the amount of argon gas used.

[0028] (5) During the feeding process of this invention, the feeding speed can be precisely controlled at any time by raising and lowering the lifting mechanism in the middle of the storage chamber, avoiding metal contamination accidents caused by the burying cone phenomenon. The hourglass-shaped feeding port combined with the conical bottom support changes the feeding path, and the shape of the raw material entering the quartz crucible changes. The scattered area of ​​the raw material is reduced and the concentration is significantly improved. The thickness of the raw material center is significantly increased, avoiding premature melting of the raw material in the center and completely solving the abnormal bubbling and splashing of silicon. Attached Figure Description

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0030] Figure 1 This is a three-dimensional view of the overall structure of the feeding device.

[0031] Figure 2 This is a longitudinal cross-sectional view of the feeding device.

[0032] Figure 3 This is a schematic diagram of the material discharge port at the bottom of the storage chamber.

[0033] Figure 4 This is a schematic diagram of the overall structure of the lifting mechanism.

[0034] Figure 5 This is a schematic diagram of the overall structure of the bottom support mechanism.

[0035] Figure 6 This is a schematic diagram of the chassis structure.

[0036] Figure 7 This is a schematic diagram of the base support column structure.

[0037] Figure 8 This is a schematic diagram of the overall structure of the central support mechanism.

[0038] Figure 9 This is a schematic diagram of the overall structure of the guiding mechanism.

[0039] Figure 10 This is a schematic diagram of the dust cover structure.

[0040] Figure 11 This is a schematic diagram of the guide plate structure.

[0041] Figure 12 This is a schematic diagram of the installation of the top protective structure and the guiding mechanism.

[0042] Figure 13 This is a schematic diagram of the structure of the protective cover for the storage chamber.

[0043] Figure 14 This is a diagram showing the working status of the feeding device.

[0044] Figure 15 This is a diagram showing the feeding effect of the feeding device.

[0045] Figure 16 This is a diagram showing the feeding effect of a traditional feeding device.

[0046] The reference numerals in the attached figures represent:

[0047] 10-Storage chamber; 101-Conical discharge port; 20-Lifting mechanism; 201-Conical base; 202-Long connecting rod; 203-T-nut; 30-Bottom support mechanism; 301-Chassis; 302-Angular contact single-row ball bearing; 303-Bottom support column; 304-First groove; 305-Second groove; 306-Support column fixing screw; 40-Middle support mechanism; 401-Middle guide plate; 402-Middle support plate; 403-Extension screw; 404-Support plate support column; 405-Clamping flap; 406 - Fastening nut; 407- Flow guide groove; 50- Guiding mechanism; 501- Dust cover; 502- Guide plate; 503- Guide plate anti-loosening nut; 504- Circular countersunk hole; 505- T-slot; 506- Insertion block; 507- Limiting groove; 60- Top protection structure; 601- Storage chamber protection cover; 602- Protection cover fixing screw; 603- Crossbeam; 604- Semi-circular feeding port; 605- Limiting step; 70- Single crystal furnace auxiliary chamber; 80- Single crystal furnace main chamber; 801- Throat step; 90- Quartz crucible. Detailed Implementation

[0048] The present invention can be better understood from the following embodiments.

[0049] Combination Figure 1 and Figure 2This invention relates to a particle silicon feeding device for a single crystal furnace, comprising a storage chamber 10, a lifting mechanism 20, a bottom support mechanism 30, a middle support mechanism 40, and a guiding mechanism 50. The lifting mechanism 20 is disposed throughout the storage chamber 10 and can move up and down within the storage chamber 10. When the lifting mechanism 20 is lifted, its bottom is locked with the discharge port of the storage chamber 10, and it can drive the storage chamber 10 to move up and down together. When the lifting mechanism 20 is lowered so that its bottom separates from the discharge port of the storage chamber 10, the silicon material in the storage chamber 10 falls from the discharge port into the quartz crucible below. The bottom of the lifting mechanism 20 is pressed against the bottom support mechanism 30. The middle support mechanism 40 is disposed on the middle side wall of the storage chamber 10. The guiding mechanism 50 is disposed at the top of the storage chamber 10 and is used to limit the lateral movement of the lifting mechanism 20.

[0050] The storage chamber 10 is a hollow quartz tube with a length of 2400 mm. It has annular flange structures at the top and middle and is used to store granular silicon raw materials.

[0051] Combination Figure 3 As shown, the lower end of the storage chamber 10 is provided with a conical discharge port 101 that gradually narrows from top to bottom; the bottom of the lifting mechanism 20 is provided with a conical base 201 that gradually increases from top to bottom, and the conical base 201 is adapted to the conical discharge port 101; when the conical base 201 separates downward from the conical discharge port 101, the granular silicon raw material in the storage chamber 10 falls onto the conical base 201 along the conical discharge port, and then spreads downward along the conical base 201 and finally falls into the quartz crucible below.

[0052] Because the storage chamber 10 adopts an irregular structure design, an hourglass-shaped conical discharge port is set in the annular shape inside the lower opening. The conical structure of this discharge port perfectly matches the upper conical surface of the conical base 201, forming a tight fit between the conical surfaces, which can effectively prevent small particles of silicon from leaking out along the gaps. At the same time, this fit between the conical surfaces will effectively improve the service life of the conical base 201 and avoid furnace slump accidents. Traditional conical bases 201 are only subjected to vertical downward pressure, and due to their large weight, they are easily damaged. Once the conical base 201 is damaged during feeding, a furnace slump accident is likely to occur. The conical surface fit adopted in this invention directly changes the force direction of the conical base 201. The overall force is perpendicular to the conical surface and points annularly towards the center of the conical base 201, which will greatly reduce the vertical downward force on the conical base 201.

[0053] To slow down the descent of the raw materials without affecting their descent or causing jamming, the inner wall of the conical discharge port 101 has an inclination angle of 60°; the outer wall of the conical base 201 has an inclination angle of 60°.

[0054] Combination Figure 4The lifting mechanism 20 includes a long connecting rod 202, a conical base 201, and T-nuts 203. The T-nuts 203 are a pair, threaded onto both ends of the long connecting rod 202. The conical base 201 has a through hole in its center, and is fitted onto the bottom of the long connecting rod 202, secured by the T-nuts 203 passing through its central through hole. The long connecting rod 202 is made of high-temperature resistant stainless steel, and its outer surface can be wrapped with polytetrafluoroethylene (PTFE) material. This completely prevents the granular silicon entering the storage chamber 10 from contacting the metal, thus preventing raw material contamination.

[0055] Combination Figures 5 to 7 The bottom support mechanism 30 includes a chassis 301, an angular contact single-row ball bearing 302, and a bottom support column 303; the chassis 301 has an opening at the upper end and can accommodate the storage cavity 10; the angular contact single-row ball bearing 302 is rotatably mounted at the center of the chassis 301; the bottom of the bottom support column 303 is mounted on the angular contact single-row ball bearing 302, and the top is used to support the tapered bottom support 201.

[0056] The base support column 303 has a first groove 304 at its top for receiving the conical base 201, and a second groove 305 at its bottom for engaging the angular contact single-row ball bearing 302. A support column fixing screw 306 passes through the center of the base support column 303. The bottom end of the support column fixing screw 306 is a smooth section, which is movably inserted into the boss at the center of the lower chassis 301, so that the support column fixing screw 306 and the base support column 303 can rotate together on the angular contact single-row ball bearing 302. This allows the entire feeding device to rotate 360 ​​degrees, facilitating 360-degree inspection and cleaning of the granular silicon feeding device, and preventing the external parts of the device from loosening and falling off, and preventing silicon powder from adhering and being unable to be cleaned in time.

[0057] A set of bolt holes is provided on the chassis 301, which can be used to fix the entire bottom support mechanism 30 to the transport vehicle by bolts. Then, the storage chamber 10 and the lifting mechanism 20 are installed on the bottom support mechanism 30 in sequence, and then transported to the feeding station by the transport vehicle.

[0058] Combination Figure 8As shown, the central support mechanism 40 includes a central guide plate 401, a central support plate 402, an extension screw 403, and a support plate column 404. The central guide plate 401 has a set of retaining flaps 405 on its inner side, which are aligned with the central flange of the storage cavity 10 and connected by the longitudinally penetrating extension screw 403. The central support plate 402 is sleeved on the outer wall of the storage cavity 10 and located below the central guide plate 401, and is connected to the central guide plate 401 by a set of longitudinally penetrating extension screws 403. The support plate pillar 404 is sleeved on the extension screw 403, and its number can be increased or decreased according to the distance between the central guide plate 401 and the central support plate 402. The extension screw 403 passes through the central support plate 402, the support plate pillar 404, the central flange of the storage cavity 10, and the central guide plate 401 from bottom to top, and is then fixed by the fastening nut 406. The central support plate 402 is provided with vertically hollowed-out guide grooves, and a guide gap is left between the central guide plate 401 and the outer wall of the storage cavity 10. This ensures that argon gas can pass smoothly, avoids abnormal backflow of gas from the furnace platform, and reduces the amount of argon gas used.

[0059] Combination Figures 9 to 11 The guiding mechanism 50 includes a dust cover 501, a guide plate 502, and a guide plate anti-loosening nut 503. The dust cover 501 covers the top of the storage chamber 10 and has a circular countersunk hole 504 at its center. A set of T-shaped slots 505 are arranged circumferentially around the circular countersunk hole 504. The circular countersunk hole 504 has a longitudinal through hole for the lifting mechanism 20 to pass through. The guide plate 502 is a right-angled triangular plate structure. The bottom right-angled side of the plate has a plug-in block 506 that cooperates with the T-shaped slot 505. A set of guide plates 502 are respectively installed on the dust cover 501 through the plug-in block 506 at their bottom and are fixed by the guide plate anti-loosening nut 503 screwed into the circular countersunk hole 504.

[0060] The assembly method of the guide mechanism 50 is as follows: Place the dust cover 501 with the four evenly distributed T-shaped slots 505 facing upwards, and insert the guide plate 502 with the I-shaped plug 506 at the lower end into the four T-shaped slots 505 of the dust cover 501 in sequence. After all the installation is completed, screw the guide plate anti-loosening nut 503 into the circular countersunk hole 504 in the center of the upper end face of the dust cover 501. At this time, the guide plate 502 will not be able to be removed, so that the dust cover 501, the guide plate 502 and the guide plate anti-loosening nut 503 form a combination.

[0061] Combination Figure 12 and Figure 13The single-crystal furnace particle silicon feeding device also includes a top protection structure 60; the top protection structure 60 includes a storage chamber protective cover 601 and a protective cover fixing screw 602; the storage chamber protective cover 601 covers the top inlet of the storage chamber 10, and its lower edge is connected and fixed to the upper flange of the storage chamber 10 through a set of protective cover fixing screws 602; a crossbeam 603 is provided in the middle of the storage chamber protective cover 601, and a pair of semi-circular feeding ports 604 for feeding are provided on both sides of the crossbeam 603, and a longitudinal through hole for the lifting mechanism 20 to pass through is provided in the center of the crossbeam 603; a set of limiting steps 605 is provided on the outer ring of the storage chamber protective cover 601, and a set of limiting grooves 507 is provided on the outer ring of the dust cover 501, the dust cover 501 covers the storage chamber protective cover 601, and the limiting grooves 507 are engaged with the corresponding limiting steps 605.

[0062] During assembly, the storage chamber protective cover 601 is directly fitted onto the top of the storage chamber 10. The lower edge of the storage chamber protective cover 601 is then fixed to the upper flange of the storage chamber 10 using the protective cover fixing screw 602, effectively protecting the storage chamber 10. Subsequently, the dust cover 501 is placed on the storage chamber protective cover 601, and the limiting groove 507 engages with the limiting step 605, thereby restricting the circumferential rotation of the dust cover 501.

[0063] Multiple guide plates 502 can be configured, forming an overall conical structure to facilitate guiding the entire device into the auxiliary chamber and avoid collisions with the lower edge of the auxiliary chamber. To prevent the guide plates 502 from falling off, guide plate anti-loosening nuts 503 are installed. The guide plate anti-loosening nuts 503 are screwed into the central threaded countersunk hole of the dust cover 501, effectively sealing the T-slot inlet and preventing the guide plate anti-loosening nuts 503 from falling off, thus effectively ensuring the safety of the guiding mechanism. At the same time, the guiding mechanism also has the function of suppressing silicon powder volatilization. The dust cover 501 covers the upper part of the storage chamber protective cover 601, effectively and tightly sealing the upper end of the granular silicon feeding device. This prevents silicon powder from volatilizing from the upper port of the storage chamber 10 during subsequent feeding, which would affect the crystal formation of the furnace.

[0064] Combination Figure 14 As shown, the above-mentioned feeding device is used for secondary feeding of granular silicon, and the method includes the following steps:

[0065] S1: Install and fix the bottom support mechanism 30 on the transport vehicle, and then install the storage chamber 10, the middle support mechanism 40, the guide mechanism 50 and the lifting mechanism 20 in sequence, and place them on the bottom support mechanism 30 as a whole.

[0066] S2: First remove the guide mechanism 50 at the top of the storage chamber 10 and load granular silicon raw material into the storage chamber 10; at this time, the lifting mechanism 20, supported by the bottom support mechanism 30, is clamped to the discharge port of the storage chamber 10 to block the granular silicon from falling.

[0067] S3: After the granular silicon is full, install the guide mechanism 50 and rotate the storage chamber 10 on the bottom support mechanism 30 to check and clean the entire device.

[0068] S4: Transport the entire device to the furnace platform to be fed by a transport vehicle, connect the top of the lifting mechanism 20 to the elevator of the single crystal furnace auxiliary chamber, and use the elevator and the lifting mechanism 20 to lift the entire feeding device containing granular silicon.

[0069] S5: Slowly lift the entire feeding device into the sub-chamber 70 of the single crystal furnace. Use the guide mechanism 50 to avoid the storage chamber 10 from colliding with the lower edge of the sub-chamber. After the upper part of the feeding device enters the sub-chamber, use the middle support mechanism 40 to guide it and avoid the storage chamber 10 from colliding with the interior of the sub-chamber.

[0070] S6: After the entire feeding device enters the sub-chamber of the single crystal furnace and is purified, the feeding device will begin to descend. Argon gas will be introduced into the top of the sub-chamber. The flow-guiding structure of the middle support mechanism 40 will be used to avoid the problem of ash adhering to the furnace wall caused by argon gas backflow.

[0071] S7: When the feeding device descends to a suitable height, the middle support mechanism 40 will contact the throat step 801 above the main chamber of the single crystal furnace 80 and will not be able to descend further, thus completing the preparation work for feeding.

[0072] S8: Lower the lifting mechanism 20. At this time, the bottom of the lifting mechanism 20 is separated from the feeding port. The bottom conical feeding port of the storage chamber 10 is opened. The granular silicon raw material in the storage chamber 10 falls along the conical feeding port to the bottom of the lifting mechanism 20, and then spreads down along the bottom of the lifting mechanism 20 and finally falls into the quartz crucible 90 below.

[0073] Combination Figure 15 and Figure 16 In traditional feeding devices, the silicon material flows vertically down the path and then spreads out in a ring along the bottom support. The rapid descent of the material makes it difficult to control the feeding speed, and it easily leads to a "buried cone" phenomenon, causing metal contamination. Furthermore, the large area of ​​material spillage, the easy volatilization of silicon powder, and the crater-like shape formed after the material falls are all problems. Figure 16 The diameter of the raw material spill area is D1, and the center height is H1. The raw material flow path of this invention (e.g., ...) Figure 15The raw material descends vertically to the conical discharge port 101. This annular constriction is an internal hourglass-shaped constriction, which effectively slows down the descent speed of the raw material without affecting its descent or causing jamming. After passing the constriction, the raw material is blocked by the annular outer wall of the conical discharge port 101 and will still descend vertically. The discharge speed can be precisely controlled at any time by the lifting mechanism 20 in the lifting and lowering storage chamber, avoiding metal contamination accidents caused by the cone burying phenomenon. The raw material entering the quartz crucible 90 has a high concentration and minimal silicon powder volatilization. The diameter of the scattered area after the raw material descends is D2, and the center height is H2. D1 is more than twice D2, and H1 is more than twice H2. Due to the special design of this invention, the flow path of the raw material is changed, the accumulation shape of the raw material entering the quartz crucible changes, the scattered area is significantly reduced, silicon powder volatilization is reduced, and the center thickness of the raw material is significantly increased. The deep pit in the center of the materialless area formed below the bottom support in the traditional feeding method is melted in advance, and the bubbling and silicon splashing will be completely solved.

[0074] This invention provides a concept and method for a particle silicon feeding device and method for a single crystal furnace. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A granular silicon feeding device for a single crystal furnace, characterized in that, The system includes a storage chamber (10), a lifting mechanism (20), a bottom support mechanism (30), a middle support mechanism (40), and a guide mechanism (50). The lifting mechanism (20) is disposed inside the storage chamber (10) and can move up and down within the storage chamber (10). When the lifting mechanism (20) is lifted, its bottom is locked with the discharge port of the storage chamber (10) and can drive the storage chamber (10) to move up and down together. When the lifting mechanism (20) is lowered so that its bottom is separated from the discharge port of the storage chamber (10), the silicon material in the storage chamber (10) falls from the discharge port into the quartz crucible below. The bottom of the lifting mechanism (20) is pressed against the bottom support mechanism (30). The middle support mechanism (40) is disposed on the middle side wall of the storage chamber (10). The guide mechanism (50) is disposed on the top of the storage chamber (10) and is used to limit the lateral movement of the lifting mechanism (20). The storage chamber (10) is a hollow circular tube, which is used to store granular silicon raw materials. The lower end of the storage chamber (10) is provided with a tapered discharge port (101) that gradually narrows from top to bottom. The bottom of the lifting mechanism (20) is provided with a tapered base (201) that gradually increases from top to bottom. The tapered base (201) is adapted to the tapered discharge port (101). When the tapered base (201) separates downward from the tapered discharge port (101), the granular silicon raw materials in the storage chamber (10) fall onto the tapered base (201) along the tapered discharge port, and then spread downward along the tapered base (201) and finally fall into the quartz crucible below. The central support mechanism (40) includes a central guide plate (401), a central support plate (402), an extension screw (403), and a support plate pillar (404). The central guide plate (401) has a set of latches (405) on its inner side. The latches (405) are aligned with the central flange of the storage cavity (10) and connected by a longitudinally penetrating extension screw (403). The central support plate (402) is sleeved on the outer wall of the storage cavity (10) and located below the central guide plate (401), connected to the central guide plate (401) by a set of longitudinally penetrating extension screws (403). The support plate pillar (404) is sleeved on the extension screw (403), and the number can be increased or decreased according to the distance between the central guide plate (401) and the central support plate (402); the extension screw (403) passes through the central support plate (402), the support plate pillar (404), the central flange of the storage cavity (10), and the central guide plate (401) from bottom to top, and is then fixed by the fastening nut (406); the central support plate (402) is provided with a guide groove (407) with hollowed-out upper and lower parts, and a guide gap is left between the central guide plate (401) and the outer wall of the storage cavity (10).

2. The granular silicon feeding device for a single crystal furnace according to claim 1, characterized in that, The inclination angle of the inner wall of the conical discharge port (101) is 60-90°; the inclination angle of the outer wall of the conical base (201) is 60-120°.

3. The granular silicon feeding device for a single crystal furnace according to claim 1, characterized in that, The lifting mechanism (20) includes a long connecting rod (202), a conical base (201), and a T-nut (203); the T-nut (203) is a pair, which are respectively threaded onto the two ends of the long connecting rod (202); the conical base (201) has a through hole in the center, and the conical base (201) is sleeved on the bottom end of the long connecting rod (202) and fixed by the T-nut (203) that passes through its central through hole.

4. The granular silicon feeding device for a single crystal furnace according to claim 1, characterized in that, The bottom support mechanism (30) includes a chassis (301), an angular contact single-row ball bearing (302), and a bottom support column (303); the chassis (301) has an opening at the top and is able to accommodate the storage cavity (10); the angular contact single-row ball bearing (302) is rotatably mounted at the center of the chassis (301); the bottom of the bottom support column (303) is mounted on the angular contact single-row ball bearing (302), and the top is used to support the tapered bottom support (201).

5. The granular silicon feeding device for a single crystal furnace according to claim 4, characterized in that, The bottom support column (303) has a first groove (304) at the top for receiving the conical bottom support (201) and a second groove (305) at the bottom for engaging the angular contact single-row ball bearing (302). A support column fixing screw (306) passes through the center of the bottom support column (303). The bottom end of the support column fixing screw (306) is a smooth section, which is movably inserted into the boss in the center of the lower chassis (301), so that the support column fixing screw (306) and the bottom support column (303) can rotate together on the angular contact single-row ball bearing (302).

6. The granular silicon feeding device for a single crystal furnace according to claim 1, characterized in that, The guiding mechanism (50) includes a dust cover (501), a guide plate (502), and a guide plate anti-loosening nut (503). The dust cover (501) covers the top of the storage cavity (10), and has a circular countersunk hole (504) in its center. A set of T-shaped slots (505) are arranged around the circular countersunk hole (504). The circular countersunk hole (504) has a longitudinal through hole in its center for the lifting mechanism (20) to pass through. The guide plate (502) is a right-angled triangular plate structure. The bottom right-angled side of the plate has a plug-in block (506) that cooperates with the T-shaped slot (505). A set of guide plates (502) are installed on the dust cover (501) through the plug-in block (506) at their bottom, and are fixed by the guide plate anti-loosening nut (503) screwed into the circular countersunk hole (504).

7. The granular silicon feeding device for a single crystal furnace according to claim 6, characterized in that, It also includes a top protective structure (60); the top protective structure (60) includes a storage chamber protective cover (601) and protective cover fixing screws (602); the storage chamber protective cover (601) covers the top inlet of the storage chamber (10), and its lower edge is connected and fixed to the upper flange of the storage chamber (10) through a set of protective cover fixing screws (602); a crossbeam (603) is provided in the middle of the storage chamber protective cover (601), and the crossbeam (603) has space on both sides for use At the pair of semi-circular feeding ports (604) for feeding, the center of the crossbeam (603) has a longitudinal through hole for the lifting mechanism (20) to pass through; the outer ring of the storage chamber protective cover (601) is provided with a set of limiting steps (605), and the outer ring of the dust cover (501) is provided with a set of limiting grooves (507). The dust cover (501) covers the storage chamber protective cover (601), and the limiting grooves (507) are engaged with the corresponding limiting steps (605).

8. The method for secondary feeding of granular silicon using the feeding device of claim 1, characterized in that, The steps include the following: S1: Install and fix the bottom support mechanism (30) on the transport vehicle, and then install the storage chamber (10), the middle support mechanism (40), the guide mechanism (50) and the lifting mechanism (20) in sequence, and place them on the bottom support mechanism (30) as a whole; S2: First remove the guide mechanism (50) at the top of the storage chamber (10) and load granular silicon raw material into the storage chamber (10); at this time, the lifting mechanism (20) is supported by the bottom support mechanism (30) and clamps with the discharge port of the storage chamber (10) to block the granular silicon from falling. S3: After the granular silicon is filled, install the guide mechanism (50) and rotate the storage chamber (10) on the bottom support mechanism (30) to check and clean the entire device; S4: Transport the entire device to the furnace platform to be fed by a transport vehicle, connect the top of the lifting mechanism (20) to the single crystal furnace auxiliary chamber elevator, and use the elevator and the lifting mechanism (20) to lift the entire feeding device containing granular silicon. S5: Slowly lift the entire feeding device into the sub-chamber of the single crystal furnace. Use the guiding mechanism (50) to avoid collision between the storage chamber (10) and the lower edge of the sub-chamber. After the upper part of the feeding device enters the sub-chamber, use the middle support mechanism (40) to guide it and avoid collision between the storage chamber (10) and the interior of the sub-chamber. S6: After the feeding device enters the sub-chamber of the single crystal furnace and is purified, the feeding device will be lowered. Argon gas will be introduced into the top of the sub-chamber. The flow-guiding structure of the middle support mechanism (40) will be used to avoid the problem of ash hanging on the furnace wall caused by argon gas backflow. S7: When the feeding device descends to a suitable height, the middle support mechanism (40) will be unable to descend further when it contacts the throat step above the main chamber of the single crystal furnace, thus completing the preparation work for feeding. S8: Lower the lifting mechanism (20). At this time, the bottom of the lifting mechanism (20) separates from the feeding port, the bottom conical feeding port of the storage chamber (10) opens, and the granular silicon raw material in the storage chamber (10) falls along the conical feeding port to the bottom of the lifting mechanism (20), and then spreads down along the bottom of the lifting mechanism (20) and finally falls into the quartz crucible below.

Images