Silicon feedstock charging device

Abstract

This disclosure provides a silicon raw material feeding device, belonging to the field of single-crystal silicon preparation technology. The silicon raw material feeding device includes: a barrel, a pull rod, and a bottom cover assembly. The barrel includes a cylinder body and a buffer section located at the bottom of the cylinder body. The cylinder body has a receiving cavity extending along the barrel's axial direction, and the buffer section has a buffer cavity extending along the barrel's axial direction, communicating with the receiving cavity. The pull rod is vertically and flexibly inserted into the barrel along its axial direction. The bottom cover assembly includes a first cone and a second cone. The first cone is used to open and close the bottom opening of the buffer section, and the second cone is used to open and close the bottom opening of the cylinder body. Both the first and second cones are located on the pull rod, with the second cone positioned above the first cone. The silicon raw material feeding device provided by this disclosure, through the coordinated design of the barrel, buffer section, pull rod, and the first and second cones, achieves segmented control and potential energy buffering of the feeding path, effectively suppressing silicon liquid sputtering during feeding.

Description

Technical Field

[0001] This disclosure belongs to the field of monocrystalline silicon preparation technology, specifically relating to a silicon raw material feeding device. Background Technology

[0002] In recent years, with the rapid development of solar photovoltaic technology, photovoltaic cells have been widely used globally, and the related industrial chain has become increasingly complete. During the manufacturing process of photovoltaic cells, a large amount of broken silicon wafers is inevitably generated, whether in the silicon wafer slicing stage or in the cell production and processing stages. If these broken silicon wafers are not effectively recycled and utilized, they will not only cause a significant waste of resources but also have a negative impact on the environment.

[0003] The recycling and reuse of broken silicon wafers mainly relies on purification processes, the most common being ingot casting purification and single-crystal Czochralski purification. Among these, the single-crystal Czochralski purification process is widely used because it can obtain high-purity, high-quality single-crystal silicon. In actual production, in order to extend the service life of expensive quartz crucibles, silicon raw materials are usually added in stages and multiple times during the single-crystal pulling process, i.e., secondary re-addition of silicon material.

[0004] In practice, to prevent the silicon raw material from softening and adhering to the feeding cylinder due to heat, the feeding cylinder is often kept at a certain distance from the molten silicon surface in the quartz crucible before feeding. However, this feeding method causes the silicon material to fall freely from a considerable height, impacting the molten silicon surface and easily causing silicon splashing. This increases raw material loss and also poses safety hazards to the production environment. Utility Model Content

[0005] The purpose of this disclosure is to provide a silicon raw material feeding device that can reduce the impact and sputtering of molten silicon during the feeding of crushed raw materials.

[0006] To achieve the above objectives, the technical solution provided in this disclosure is as follows:

[0007] In a first aspect, this disclosure provides a silicon raw material feeding device, comprising: a material cylinder, a pull rod, and a bottom cover assembly; the material cylinder includes a cylindrical body and a buffer portion disposed at the bottom of the cylindrical body, the cylindrical body having a receiving cavity extending along the axial direction of the material cylinder, and the buffer portion having a buffer cavity extending along the axial direction of the material cylinder, the buffer cavity communicating with the receiving cavity. The pull rod is vertically and flexibly inserted into the material cylinder along the axial direction of the material cylinder. The bottom cover assembly includes a first cone and a second cone, the first cone being used to open and close the bottom opening of the buffer portion, and the second cone being used to open and close the bottom opening of the cylindrical body, both the first cone and the second cone being disposed on the pull rod, with the second cone located above the first cone.

[0008] In one or more embodiments, the inner wall of the cylinder is provided with a plurality of partition plates, which protrude toward the tie rod and extend along the axial direction of the cylinder, dividing the receiving cavity into a plurality of material filling zones.

[0009] In one or more embodiments, there is a gap between the partition and the pull rod.

[0010] In one or more embodiments, the pull rod is provided with a blocking plate for closing part of the material filling area. The blocking plate can rotate with the pull rod to switch the closed material filling area.

[0011] In one or more embodiments, at least one of the partition plates is provided with a slot that extends through the partition plate, and the blocking plate can switch positions between adjacent material filling zones through the slot.

[0012] In one or more embodiments, when the bottom openings of the buffer section and the cylinder are closed, the blocking plate corresponds to the slot position, and the distance from the slot to the bottom of the partition plate is greater than or equal to the maximum descent distance when the pull rod is feeding.

[0013] In one or more embodiments, the number of partitions is four, and the four partitions are arranged in pairs opposite each other along the radial direction of the cylinder to divide the receiving cavity into four material filling areas, with an included angle of 90° between two adjacent partitions.

[0014] In one or more embodiments, the blocking plate includes a first blade and a second blade arranged opposite to each other, the first blade and the second blade being used to close two opposite material filling areas respectively; two of the four partition plates arranged opposite to each other are provided with slots for the first blade and the second blade to rotate.

[0015] In one or more embodiments, the included angle α between the conical surface and the bottom surface of the first cone is 40 to 50°, the included angle β between the conical surface and the bottom surface of the second cone is 50 to 60°, and the included angle α is 10° smaller than the included angle β.

[0016] In one or more embodiments, the distance between the first cone and the second cone is 25 to 35 mm; and / or the bottom diameter of the first cone is equal to the diameter of the bottom opening of the buffer section, and the bottom diameter of the second cone is equal to the diameter of the bottom opening of the cylinder.

[0017] In one or more embodiments, the outer diameter of the buffer section is 300-350 mm, the inner diameter of the buffer section is 270-320 mm; and / or the outer diameter of the cylinder is 250-300 mm, and the wall thickness of the cylinder is 10-20 mm.

[0018] The silicon raw material feeding device disclosed herein achieves segmented control and potential energy buffering of the feeding path through the coordinated design of the cylinder, buffer section, pull rod, and first and second cones. The two cones driven by the pull rod respectively close the bottom opening of the cylinder and the buffer section, and open during feeding, so that the broken silicon wafers enter the buffer chamber before falling into the high-temperature crucible, and are buffered on the cone surface of the first cone, which significantly reduces the falling potential energy and effectively suppresses silicon liquid sputtering. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of a silicon raw material feeding device in one embodiment of the present disclosure;

[0021] Figure 2 for Figure 1 A cross-sectional view of the silicon raw material feeding device in a closed state;

[0022] Figure 3 for Figure 1 A cross-sectional view of the silicon raw material feeding device in the feeding state;

[0023] Figure 4 This is a three-dimensional structural diagram of the barrel in one embodiment of the present disclosure;

[0024] Figure 5 This is a three-dimensional structural diagram of the pull rod and bottom cover assembly in one embodiment of the present disclosure.

[0025] Explanation of key figure labels:

[0026] 1-Cylinder, 11-Cylinder body, 111-Receiving cavity, 12-Buffer section, 121-Buffer cavity, 13-Divider plate, 14-Material filling area, 15-Gate, 2-Pull rod, 21-Blocking plate, 211-First blade, 212-Second blade, 3-Bottom cover assembly, 31-First cone, 32-Second cone. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0028] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0029] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. In the embodiments shown in this disclosure, directional representations such as up, down, left, right, front, and back are relative and are used to explain the relative structure and movement of different components in this disclosure. These representations are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, then these representations are considered to change accordingly.

[0030] With the booming development of the solar photovoltaic industry, the recycling of silicon wafer fragments has become a key link in reducing production costs and environmental pollution. In the Czochralski process for monocrystalline silicon, silicon wafer fragments, as an important raw material, need to be re-added to the crucible via a feeding device to replenish the molten silicon. However, traditional feeding devices face the following problems during operation: when the feeding device is close to the high-temperature crucible, the silicon wafer fragments soften due to heat radiation and adhere to the inner wall of the feeding device, resulting in incomplete feeding and the need for frequent acid washing, increasing maintenance costs and shortening the life of the device; if the feeding device is placed at a distance to avoid softening the silicon material, the silicon material falls into the crucible from a greater distance with a stronger impact force, causing silicon molten metal splashing, contaminating the equipment, affecting the quality of monocrystalline silicon, and posing safety hazards.

[0031] Based on this, this disclosure proposes a novel approach to the feeding device: by introducing heat insulation and buffering mechanisms, the feeding process of crushed silicon wafers is optimized to overcome the defects of silicon material softening and adhesion and silicon melt sputtering in existing technologies. Specifically, the silicon raw material feeding device provided in this disclosure increases the thermal isolation distance between the silicon material and the high-temperature crucible by setting a buffer structure at the bottom of the barrel, thereby reducing the impact of thermal radiation on the silicon material and preventing silicon material softening and adhesion; and by introducing a buffering mechanism in the feeding path, the potential energy of the silicon material falling into the crucible is reduced, thereby reducing the impact force on the surface of the silicon melt and suppressing silicon melt sputtering, improving single crystal quality and production safety.

[0032] Please refer to Figures 1 to 5 As shown, a silicon raw material feeding device in one embodiment of this disclosure includes a material cylinder 1, a pull rod 2, and a bottom cover assembly 3. The material cylinder 1 includes a cylinder body 11 and a buffer section 12 disposed at the bottom of the cylinder body 11. The cylinder body 11 has a receiving cavity 111 extending axially along the material cylinder 1, and the buffer section 12 has a buffer cavity 121 extending axially along the material cylinder 1, the buffer cavity 121 communicating with the receiving cavity 111. The pull rod 2 is vertically and flexibly inserted into the material cylinder 1 along the axial direction of the material cylinder 1. The bottom cover assembly 3 includes a first cone 31 and a second cone 32. The first cone 31 is used to open and close the bottom opening of the buffer section 12, and the second cone 32 is used to open and close the bottom opening of the cylinder body 11. Both the first cone 31 and the second cone 32 are disposed on the pull rod 2, and the second cone 32 is located above the first cone 31.

[0033] The material cylinder 1 is the material container of the feeding device, consisting of a cylinder body 11 and a buffer section 12 connected to the bottom. The cylinder body 11 is generally cylindrical, with an axially penetrating cavity 111 inside for storing silicon raw materials (such as crushed silicon wafers). The buffer section 12 is located at the bottom of the cylinder body 11, and is generally designed as an inverted cup-shaped structure. Its outer diameter is preferably larger than the outer diameter of the cylinder body 11, and it has an axially penetrating buffer cavity 121 that communicates with the cavity 111 in the axial direction. This structural relationship ensures that the silicon raw material can sequentially transition from the cavity 111 to the buffer cavity 121 under the action of gravity, providing a continuous path for subsequent feeding.

[0034] The inverted cup-shaped design and large outer diameter of the buffer section 12 effectively block the heat radiation of the high-temperature silicon liquid when it is close to the crucible, preventing the silicon material in the receiving cavity 111 from softening and sticking due to heat, thereby reducing the need for cleaning the device and extending its service life. The buffer cavity 121 provides a buffer space for the silicon material to fall through its geometry, reducing the falling speed and the impact on the silicon liquid in the crucible.

[0035] The pull rod 2 is inserted through the middle of the material cylinder 1 and can move up and down along the axial direction of the material cylinder 1. It is the component used to drive the opening and closing of the bottom cover assembly 3 in the entire device. The setting of the pull rod 2 makes the feeding process no longer dependent on the static channel structure, but can achieve the opening and closing control of the material outlet by adjusting its position. The operator can adjust the position of the pull rod 2 according to the thermal environment of the crucible to release the silicon raw material at the appropriate time, avoiding premature exposure to the high temperature environment or problems caused by improper material feeding.

[0036] The bottom cover assembly 3 consists of a first cone 31 and a second cone 32 fixed to the pull rod 2, forming an upper and lower hierarchical arrangement to control the opening and closing of the bottom openings of the buffer section 12 and the cylinder 11, respectively. This layout ensures that at different height positions of the pull rod 2, both cones can act on the bottom openings of the cylinder 11 and the buffer section 12, respectively, to simultaneously open or close the feeding path. The second cone 32 is located at the top, with its cone surface facing upwards, serving as a sealing and guiding function. The first cone 31 is located further down, and its shape and cone angle are designed to provide a certain buffering and potential energy absorption capacity. After the material falls from the cylinder 11 into the buffer chamber 121, it first contacts the surface of the first cone 31, during which its kinetic energy is partially dissipated, thereby reducing its impact intensity on the high-temperature liquid surface.

[0037] In one exemplary embodiment, please refer to Figure 2 and Figure 4 As shown, the inner wall of the cylinder 11 is provided with multiple partition plates 13. The partition plates 13 protrude toward the pull rod 2 and extend along the axial direction of the cylinder 11, dividing the receiving cavity 111 into multiple material filling areas 14.

[0038] The partition plates 13 are plate-shaped protrusions fixed to the inner wall of the cylinder 11, and are distributed at intervals along the inner surface of the cylinder 11. The number of partition plates 13 is 2 to 4 or more, and the specific number can be set according to the usage requirements. These partition plates 13 extend radially towards the central tie rod 2 with the axis of the cylinder 11 as the center, and have a predetermined length extending along the axial direction of the cylinder 11, forming multiple independent vertical channels. Each pair of adjacent partition plates 13 defines a fan-shaped material filling area 14.

[0039] Specifically, please refer to Figure 1 and Figure 2 As shown, there is a gap between the partition plate 13 and the pull rod 2. Since the pull rod 2 is located at the center of the cylinder 11 and the partition plate 13 protrudes inward, a certain gap is reserved between the free end of the partition plate 13 and the pull rod 2, so that the pull rod 2 will not mechanically interfere with these partition plates 13 during lifting or rotation, ensuring the smoothness of its operation.

[0040] To prevent physical interference between the pull rod 2 and the partition plate 13 during lifting or rotation, a gap of about 1mm can be set between the free end of the partition plate 13 and the pull rod 2. This gap can ensure the smooth movement of the pull rod 2 and the relative independence between the structures without affecting the partitioning effect.

[0041] In one exemplary embodiment, please refer to Figure 3 and Figure 5As shown, the pull rod 2 is equipped with a blocking plate 21, which is used to close part of the material filling area 14. The blocking plate 21 can rotate with the pull rod 2 to switch the closed material filling area 14. The blocking plate 21 and the pull rod 2 can be an integrated structure, or it can be fixed at a specific height of the pull rod 2 by mechanical locking to ensure that it has a consistent rotation angle and synchronization when rotating with the pull rod 2, so as to avoid closure failure due to positional deviation.

[0042] The blocking plate 21 is positioned on the outer circumferential surface of the pull rod 2, at a height corresponding to the internal partition plates 13 of the cylinder 11. The blocking plate 21 extends outward from the circumferential surface of the pull rod 2 at a specific angle, its design incorporating the distribution angles of the internal partition plates 13 of the cylinder 11 and the spatial layout of the material filling area 14. For example, when the cylinder 11 is divided into four equally angular sector-shaped filling areas, the blocking plate 21 typically employs a double-blade structure, respectively sealing off two opposing areas. The extension length of the blocking plate 21 is slightly less than the radius chord of the angle between the partition plates 13, thus ensuring that it can block the feeding channel within the material filling area 14 without interfering with the structure of the partition plates 13.

[0043] The main function of the blocking plate 21 is to regulate the release path of the raw material. By rotating the pull rod 2, the blocking plate 21 can rotate from the currently closed material filling area 14 to the unclosed filling area, opening the previously closed area while blocking the previously open area. Combined with the lifting and lowering action of the pull rod 2, this structure can release raw materials from different areas in batches, thus achieving the function of phased feeding. In the high-temperature crystal pulling process, if all the broken silicon wafers are fed at once, it is very easy to cause violent fluctuations in the molten silicon in the crucible or the first cone 31 to be instantly submerged, thereby causing sputtering or abnormal feeding. By controlling the feeding rhythm through the blocking plate 21, this risk can be significantly reduced, improving the safety and stability of feeding.

[0044] Specifically, please refer to Figure 2 and Figure 3 As shown, at least one partition plate 13 is provided with a slot 15, which extends through the partition plate 13. The blocking plate 21 can switch positions between adjacent material filling zones 14 through the slot 15. In order to achieve selective control of the area during the feeding process, and to enable the blocking plate 21 to smoothly switch the closed material filling zone 14 during the rotation of the lever 2, a slot 15 is provided on the partition plate 13 inside the cylinder 11 to assist the blocking plate 21 in rotating and passing through.

[0045] The slot 15 extends through the partition plate 13 along its thickness direction, forming a local gap. This allows the blocking plate 21 to pass over the physical barrier of the partition plate 13 when the pull rod 2 rotates, thus smoothly moving from one material filling area 14 to an adjacent material filling area 14, achieving a switch between closed and open positions. Preferably, the slot 15 is located in the lower middle section of the partition plate 13, and its height corresponds to the position of the blocking plate 21 on the pull rod 2, allowing the blocking plate 21 to pass through the slot 15 during rotation.

[0046] Further, please refer to Figure 3 As shown, in order to ensure that the blocking plate 21 always has the ability to effectively close the designated material filling area 14 during the lifting and lowering process of the pull rod 2, when the bottom opening of the buffer part 12 and the cylinder 11 is in a closed state, the blocking plate 21 is positioned corresponding to the slot 15, and the distance d from the slot 15 to the bottom of the partition plate 13 is greater than or equal to the maximum descent distance when the pull rod 2 is feeding material.

[0047] When the device is in a closed state, i.e., when the bottom openings of the buffer section 12 and the cylinder 11 are closed by the first cone 31 and the second cone 32, the blocking plate 21 is located within the material filling area 14 it closes, and its height is exactly aligned with the slot 15 on the partition plate 13. At this time, the blocking plate 21 is located at the same height as the slot 15 and does not pass through the slot 15, ensuring that the material filling area 14 is clearly divided into closed and open states in the closed state.

[0048] To further ensure the sealing effectiveness of each material filling zone 14 during the feeding process, especially during the entire process of the pull rod 2 slowly descending from the highest position to the lowest feeding position, the vertical distance between the slot 15 and the bottom of the partition plate 13 is set to be greater than or equal to the maximum descent stroke of the pull rod 2. This ensures that during the descent of the pull rod 2, the blocking plate 21 remains within its originally sealed material filling zone 14, and is longitudinally restricted by the structure of the partition plate 13, preventing it from exceeding the filling zone and thus preventing the originally sealed raw material zone from accidentally opening due to structural misalignment.

[0049] As the pull rod 2 descends, the blocking plate 21 on it will cause the entire enclosed area to move downwards. If the slot 15 is set too low, once the blocking plate 21 slides out of the control range of the partition plate 13 structure during the descent, the originally enclosed material filling area 14 will lose its barrier protection. The silicon raw materials in the area that are not yet ready to be put into the zone may fall unexpectedly under the action of gravity and enter the buffer chamber 121, disrupting the feeding rhythm and even causing problems such as the cone being buried, severe sputtering, and overflow blockage.

[0050] In one exemplary embodiment, please refer to Figure 1 and Figure 4As shown, there are four partition plates 13. The four partition plates 13 are arranged in pairs opposite each other along the radial direction of the cylinder 11, dividing the receiving cavity 111 into four material filling areas 14. The included angle between two adjacent partition plates 13 is 90°, forming a symmetrical cross-shaped partition structure.

[0051] Four partition plates 13 protrude from the inner wall of the cylinder 11 toward the central tie rod 2, and are not connected to each other, leaving a certain gap in the middle. This divides the internal space into four material filling zones 14 without affecting the overall structural strength of the cylinder 11. These filling zones are symmetrically distributed around the tie rod 2 as the central axis, which not only maximizes space utilization but also facilitates balanced material loading and symmetrical force distribution. The axial length of the partition plates 13 is slightly less than or equal to the length of the cylinder 11, thus limiting and guiding the material along the length of the cylinder 11, preventing the material from tilting, piling up, or slipping off.

[0052] Specifically, please refer to Figure 3 and Figure 5 As shown, the blocking plate 21 includes a first blade 211 and a second blade 212 arranged opposite to each other. The first blade 211 and the second blade 212 are respectively used to close two opposite material filling areas 14; two of the four partition plates 13 are provided with slots 15 for the first blade 211 and the second blade 212 to rotate.

[0053] The baffle plate 21 is designed with a first blade 211 and a second blade 212 arranged opposite to each other, symmetrically distributed on both sides of the pull rod 2. This symmetrical arrangement not only ensures structural balance but also makes the rotational switching action during operation more balanced and smooth. The function of the first blade 211 and the second blade 212 is to close the two opposing material filling areas 14 in the receiving cavity 111 of the cylinder 11, so that in one feeding cycle, only the raw materials in the other two opposing unclosed material filling areas 14 are allowed to fall into the lower buffer cavity 121, realizing the function of batch feeding.

[0054] To coordinate with the rotation of the blocking plate 21, two of the four partition plates 13 are selected and arranged opposite to each other, and a slot 15 is formed in each of their structures. These slots 15 penetrate the partition plates 13 in the thickness direction and are set at a height corresponding to the rotation path of the blocking plate 21. In the closed state, the first blade 211 and the second blade 212 are located in two opposite material filling areas 14, respectively. When the operator raises the lever 2 to the preset height and rotates the lever 2, the first blade 211 and the second blade 212 will rotate synchronously around the axis of the lever 2. When they rotate to a 90° angle position, the two blades pass through their respective slots 15 and enter the other two material filling areas 14 that were not originally closed, thereby realizing the opening and closing conversion of the material filling areas 14.

[0055] In one exemplary embodiment, please refer to Figure 3 As shown, the included angle α between the cone surface and the bottom surface of the first cone 31 is preferably 40-50°, and the included angle β between the cone surface and the bottom surface of the second cone 32 is preferably 50-60°, and the included angle α is preferably 10° smaller than the included angle β.

[0056] The first cone 31, located at the lower part of the pull rod 2, is used to open and close the bottom outlet of the buffer section 12. Its main function is to buffer and guide the material before it falls from the buffer chamber 121 into the crucible. The smaller included angle α makes the cone surface of the first cone 31 more gentle. This design can prolong the path and time of contact between the material and the cone when it falls in, allowing its kinetic energy to be gradually released in a longer buffer path, thereby achieving the purpose of reducing impact and stabilizing the feeding process. Especially in the case of high-hardness raw materials such as crushed silicon wafers falling at high speed, it can significantly reduce the risk of sputtering and protect the stability of the silicon liquid in the crucible.

[0057] The second cone 32, located above the first cone 31, is primarily used to control the closure of the bottom opening of the cylinder 11. Its structural function emphasizes sealing performance and responsiveness. Therefore, the larger included angle β of the second cone 32 results in a steeper cone surface. During the lifting and lowering of the pull rod 2, the cone can more quickly and effectively block the opening of the cylinder 11, improving sealing efficiency and reducing the possibility of material accumulating or falling back along the cone surface during filling. Furthermore, the larger cone angle also enhances the self-cleaning ability of the second cone 32 to some extent, preventing material adhesion.

[0058] In one exemplary embodiment, please refer to Figure 2 As shown, the distance between the first cone 31 and the second cone 32 is preferably 25-35 mm. The bottom diameter of the first cone 31 is preferably equal to the diameter of the bottom opening of the buffer part 12, and the bottom diameter of the second cone 32 is preferably equal to the diameter of the bottom opening of the cylinder 11.

[0059] Silicon material enters the buffer chamber 121 from the receiving chamber 111 through the opening controlled by the second cone 32. After colliding with the first cone 31 to reduce potential energy, it slowly falls into the crucible through the opening of the buffer section 12. The 25-35mm spacing ensures coordinated movement of the two cones during the lifting and lowering of the pull rod 2, while providing sufficient space for the silicon material to be buffered within the buffer chamber 121. The matching design of the bottom diameter of the two cones and the corresponding openings ensures a sealing effect during the non-feeding stage, preventing material leakage.

[0060] In one exemplary embodiment, please refer to Figure 3As shown, the outer diameter of the buffer section 12 is preferably 300-350 mm, and the inner diameter of the buffer section 12 is preferably 270-320 mm. The outer diameter of the cylinder 11 is preferably 250-300 mm, and the wall thickness of the cylinder 11 is preferably 10-20 mm.

[0061] The outer diameter of the buffer section 12 is larger than that of the cylinder 11, forming an enlarged bottom structure. This geometric difference not only enhances the heat insulation effect but also provides a larger buffer space for the buffer cavity 121. By increasing the distance from the crucible and using the inverted cup-shaped geometric design, the heat radiation of the high-temperature silicon melt is effectively blocked, protecting the silicon material in the receiving cavity 111 from overheating and preventing adhesion. The buffer cavity 121, with an inner diameter of 270–320 mm, provides sufficient space for the silicon material to be buffered by the first cone 31 before falling into the crucible, reducing kinetic energy and impact force, thereby suppressing silicon melt sputtering.

[0062] The design of the outer diameter (250-300mm) and wall thickness (10-20mm) of the cylinder 11 balances the requirements of structural strength and lightweighting. The wall thickness range of 10-20mm ensures the durability of the cylinder 11 in high-temperature environments, while avoiding material waste caused by excessive thickness or structural fragility caused by excessive thinness.

[0063] The silicon raw material feeding device provided in this disclosure will be further explained below in conjunction with specific application scenarios.

[0064] In use, firstly, the pull rod 2 is raised to the predetermined position. At this time, the first cone 31 and the second cone 32 respectively close the bottom openings of the buffer section 12 and the cylinder 11. Simultaneously, the blocking plate 21 on the pull rod 2 is also in a rotating switching position aligned with the slot 15, closing part of the material loading area 14, thus temporarily preventing this part of the material loading area 14 from participating in this round of feeding. After completing the above preparations, the operator can add silicon raw materials such as crushed silicon wafers to the material loading area 14, filling the designated area within the receiving cavity 111.

[0065] After the raw material is loaded, the entire feeding device is placed above the crucible in the single crystal furnace, ready to perform the feeding operation. Then, the pull rod 2 is slowly moved downwards, the first cone 31 opens the bottom opening of the buffer section 12, and the second cone 32 opens the bottom opening of the cylinder 11, allowing the silicon raw material in the material loading area 14, which is not closed by the blocking plate 21, to fall under gravity and enter the buffer chamber 121 below through the bottom opening of the cylinder 11. During this process, the raw material first impacts the first cone 31 in the buffer chamber 121. The relatively gentle angle of the cone generates a certain resistance to the raw material, playing a role in buffering and decelerating, thereby reducing the falling potential energy of the raw material. The buffered silicon raw material then falls into the crucible through the bottom opening of the buffer section 12, effectively avoiding violent disturbance and splashing of the high-temperature silicon liquid, ensuring the safety of the raw material replenishment process and the stability of the crucible liquid surface.

[0066] After the initial feeding is completed, the lever 2 is raised again to prepare for the next feeding, causing the first cone 31 and the second cone 32 to return to their closed state, sealing the bottom openings of the buffer section 12 and the cylinder 11, respectively. At this time, the blocking plate 21 rises along with the lever 2, aligning with the slot 15 pre-set on the partition plate 13. By rotating the lever 2, the operator causes the blocking plate 21 to rotate and pass through the slot 15 into the previously fed material filling area 14, simultaneously opening the previously closed material filling area 14 and switching the feeding area.

[0067] Once the silicon raw material already added to the crucible has melted and is ready to receive the next round of feeding, the operator lowers lever 2 again, opening the second cone 32 and the first cone 31. The silicon raw material in the newly opened material loading zone 14 then repeats the aforementioned falling-buffering-feeding process under gravity, completing the second feeding. In this way, silicon raw material in multiple material loading zones 14 can be added in batches, effectively avoiding the risks of splashing and cone burial caused by a single concentrated feeding.

[0068] In summary, the silicon raw material feeding device provided in this disclosure achieves segmented control and potential energy buffering of the feeding path through the coordinated design of the cylinder, buffer section, pull rod, and first and second cones. The two cones driven by the pull rod respectively close the bottom opening of the cylinder and the buffer section, and open during feeding, so that the broken silicon wafers enter the buffer chamber before falling into the high-temperature crucible, and are buffered on the cone surface of the first cone, which significantly reduces the falling potential energy and effectively suppresses silicon liquid sputtering.

[0069] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A silicon raw material charging device characterized by comprising: include: A material cylinder includes a cylinder body and a buffer section disposed at the bottom of the cylinder body. The cylinder body has a receiving cavity that extends through the cylinder axis, and the buffer section has a buffer cavity that extends through the cylinder axis. The buffer cavity is in communication with the receiving cavity. A pull rod is vertically and flexibly inserted into the material cylinder along the axial direction of the cylinder; The bottom cover assembly includes a first cone and a second cone. The first cone is used to open and close the bottom opening of the buffer section, and the second cone is used to open and close the bottom opening of the cylinder. Both the first cone and the second cone are disposed on the pull rod, and the second cone is located above the first cone.

2. The silicon raw material charging apparatus according to claim 1, characterized by The inner wall of the cylinder is provided with multiple partition plates, which protrude toward the tie rod and extend along the axial direction of the cylinder, dividing the receiving cavity into multiple material filling areas.

3. The silicon raw material charging apparatus according to claim 2, characterized by There is a gap between the partition plate and the pull rod.

4. The silicon raw material charging apparatus according to claim 2, wherein The pull rod is equipped with a blocking plate, which is used to close part of the material filling area. The blocking plate can rotate with the pull rod to switch the closed material filling area.

5. The silicon raw material charging apparatus according to claim 4, wherein At least one of the partition plates is provided with a slot, the slot extending through the partition plate, and the blocking plate is able to switch positions between adjacent material filling zones through the slot.

6. The silicon raw material charging apparatus according to claim 5, wherein When the bottom openings of the buffer section and the cylinder are closed, the blocking plate corresponds to the slot, and the distance from the slot to the bottom of the partition plate is greater than or equal to the maximum descent distance when the pull rod is feeding.

7. The silicon raw material charging apparatus according to claim 4, wherein The number of partitions is four, and the four partitions are arranged in pairs opposite each other along the radial direction of the cylinder, dividing the receiving cavity into four material filling areas. The included angle between two adjacent partitions is 90°.

8. The silicon raw material charging apparatus according to claim 7, wherein The blocking plate includes a first blade and a second blade arranged opposite to each other, the first blade and the second blade being used to close two opposite material filling areas respectively; two of the four partition plates arranged opposite to each other are provided with slots for the first blade and the second blade to rotate.

9. The silicon raw material feeding device according to claim 1, characterized in that, The included angle α between the conical surface and the bottom surface of the first cone is 40-50°, and the included angle β between the conical surface and the bottom surface of the second cone is 50-60°, and the included angle α is 10° smaller than the included angle β.

10. The silicon raw material feeding device according to claim 1, characterized in that, The distance between the first cone and the second cone is 25–35 mm; and / or The bottom diameter of the first cone is equal to the diameter of the bottom opening of the buffer section, and the bottom diameter of the second cone is equal to the diameter of the bottom opening of the cylinder.

11. The silicon raw material feeding device according to claim 1, characterized in that, The outer diameter of the buffer section is 300-350 mm, and the inner diameter of the buffer section is 270-320 mm; And / or the outer diameter of the cylinder is 250-300 mm, and the wall thickness of the cylinder is 10-20 mm.

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