Hollow silicon core lap joint structure of polycrystalline silicon reduction furnace
By using the overlapping design of graphite connecting sleeves and truncated cone structures, the problem of unstable connection of hollow silicon cores was solved, achieving stability and safety in polycrystalline silicon production, reducing costs, and promoting the industrial application of hollow silicon cores.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2026-03-27
AI Technical Summary
While using large-diameter solid silicon cores improves the growth efficiency of polycrystalline silicon, existing technologies suffer from problems such as difficulty in pulling, high cost, and difficulty in splicing. Hollow silicon cores, on the other hand, are prone to furnace collapse due to unstable connections, thus limiting their industrial application.
The use of a threaded connection between a graphite connecting sleeve and a graphite connecting post, combined with the overlapping platform of a truncated cone structure and the design of a vent hole, ensures a stable connection between the hollow silicon core and the graphite base, enhances the overlapping stability, and alleviates the internal gas expansion pressure through the vent hole.
It achieves a stable connection of hollow silicon cores, avoids furnace tipping, improves equipment maintainability and safety, reduces production costs, and increases polysilicon production efficiency.
Smart Images
Figure CN224046992U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the polycrystal silicon production field especially relates to a hollow silicon core lap joint structure of polycrystal silicon reduction furnace. BACKGROUND
[0002] With the expansion of the photovoltaic industry, the demand for polycrystalline silicon continues to rise. At present, the modified Siemens method is the main technology for the production of polycrystalline silicon. In the production process, polycrystalline silicon is usually reduced by a reduction furnace, and chemical vapor deposition (CVD) technology is used to deposit polycrystalline silicon on the surface of the silicon core. The specific steps include: first, fixing the silicon core on the graphite piece, then installing the graphite piece on the conductive electrode; then, in the reduction furnace, the silicon core is composed of multiple closed "Π" shaped loops, that is, "bridging"; after installation, according to the established process, displacement, breakdown, feeding, etc. are carried out, thereby triggering the vapor deposition reaction, and the crystal grains are deposited and gradually grow on the surface of the silicon core, and finally form a polycrystalline silicon rod.
[0003] In the current technology, the lap joint of the silicon core assembly usually uses a solid round silicon core with a diameter of about 12 mm or a 15x15 mm square silicon core obtained by wire cutting. During the reduction reaction, silicon is continuously deposited on the surface of the silicon core, causing the surface area of the silicon core to gradually increase, thereby increasing the collision opportunities and frequency of reaction gas molecules with the deposition surface. If the deposition rate per unit area remains unchanged, the larger the surface area, the more polycrystalline silicon is deposited, thereby improving the production efficiency of the silicon rod. Therefore, using a larger diameter silicon core can improve the efficiency of polycrystalline silicon growth and reduce production costs.
[0004] Although large-diameter solid silicon cores can improve the production rate of the reduction process, they have the following disadvantages:
[0005] 1) The larger the diameter of the silicon core, the more difficult the drawing process, and the number of one-time drawing in the furnace is limited;
[0006] 2) The use of large-diameter solid silicon cores will increase the amount of silicon material by several times, resulting in a significant increase in cost;
[0007] 3) In addition, it is difficult to break through after the large-diameter solid silicon core is lapped.
[0008] In order to ensure production efficiency while reducing production costs, some enterprises have tried to use hollow silicon cores with a circular cross-section to replace traditional small-diameter solid silicon cores to increase production. However, although the hollow silicon core can solve some problems in the existing technology, it is not stable in connection with the electrode, and is prone to cause the phenomenon of furnace reversal, which seriously limits the industrial application of the hollow silicon core. UTILITY MODEL CONTENTS
[0009] In order to solve the above problems, the purpose of the utility model is to provide a hollow silicon core lap joint structure of a polycrystalline silicon reduction furnace.
[0010] The utility model discloses a following technical scheme implementation:
[0011] A hollow silicon core lap joint structure of polycrystal silicon reduction furnace, including graphite base, hollow silicon core and horizontal silicon plate;
[0012] The electrode insertion hole is inserted on the conductive electrode;
[0013] The graphite connecting column is coaxially arranged with the electrode insertion hole, and an outer thread is arranged on the outer periphery of the graphite connecting column;
[0014] The bottom end of the hollow silicon core is threadedly connected with the graphite connecting column;
[0015] The top end of the hollow silicon core is integrally provided with a lap joint table in the shape of a truncated cone, a lap joint hole matched with the lap joint table is arranged at each end of the horizontal silicon plate, and the positions of the two lap joint holes on one horizontal silicon plate correspond to the positions of the pair of hollow electrodes.
[0016] Further, a concave groove is arranged in the middle of the lap joint table in the circumferential direction, and the top end height of the concave groove is higher than the top surface height of the horizontal silicon plate.
[0017] Further, a first exhaust hole is arranged on the side wall of the graphite base and communicates with the electrode insertion hole and the outside of the graphite base.
[0018] Further, a second exhaust hole is arranged at the top center of the lap joint table and communicates with the inside of the hollow silicon core and the outside of the hollow silicon core.
[0019] Further, a graphite connecting sleeve is welded to the bottom end of the hollow silicon core, an inner thread is arranged on the inner surface of the graphite connecting sleeve, and the graphite connecting sleeve is threadedly connected with the graphite connecting column.
[0020] Further, the hole diameter and hole depth of the electrode insertion hole are matched with the diameter and height of the conductive electrode respectively.
[0021] Further, the opening end of the electrode insertion hole is in an open structure.
[0022] Further, the lap joint table is in the structure of a circular truncated cone.
[0023] The utility model has the advantages of:
[0024] 1. Through the threaded connection between the graphite connecting sleeve and the graphite connecting column, the connection and fixation of the hollow silicon core and the graphite base are realized, which not only ensures the stability of the connection and effectively prevents the phenomenon of furnace reversal caused by unstable connection, but also facilitates disassembly and replacement, improves the maintainability and flexibility of the equipment.
[0025] 2. The lap joint table is provided with a conical table structure, which not only increases the contact area with the horizontal silicon plate and improves the stability of the lap joint, but also facilitates the alignment and insertion with the lap joint hole, simplifies the installation process and improves the work efficiency. At the same time, compared with the cylindrical structure, the contact area of the lap joint is increased, which can avoid the situation that the temperature of the silicon core is too high, the silicon core is damaged or even the silicon core is fused due to the overloading of the current, and the stable operation of the reduction furnace is affected. In addition, the design of the concave groove further enhances the stability of the lap joint, effectively preventing the horizontal silicon plate from falling off due to air flow disturbance.
[0026] 3. The design of the exhaust hole enables the gas in the electrode insertion hole and the hollow silicon core to be timely discharged after thermal expansion, avoiding damage to the equipment or safety hazards caused by excessive internal pressure. At the same time, the exhaust hole can also realize displacement without dead angle when the furnace is started, ensuring the normal operation and safety of the equipment.
[0027] In summary, the hollow silicon core lap joint structure of the polycrystalline silicon reduction furnace has the advantages of simple installation, easy operation, good stability, convenient maintenance, high flexibility and strong safety, providing reliable technical support for the industrialized application of hollow silicon core. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.
[0029] Fig. 1 It is a structural schematic view of the embodiment;
[0030] Fig. 2 It is a top view structural schematic view of the horizontal silicon plate in the embodiment.
[0031] In the figure: graphite base 1, hollow silicon core 2, horizontal silicon plate 3, electrode insertion hole 4, concave groove 5, graphite connecting column 6, graphite connecting sleeve 7, lap joint table 8, lap joint hole 9, first exhaust hole 10, second exhaust hole 11. DETAILED DESCRIPTION
[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0033] Example 1:
[0034] like Figs. 1-2 The hollow silicon core overlapping structure of a polycrystalline silicon reduction furnace shown includes a graphite base 1, a hollow silicon core 2, and a horizontal silicon plate 3.
[0035] An electrode insertion hole 4 matching the conductive electrode is provided at the bottom end of the graphite base 1. The diameter and depth of the electrode insertion hole 4 are matched with the diameter and height of the conductive electrode, respectively. The electrode insertion hole 4 is inserted into the conductive electrode. The opening end of the electrode insertion hole 4 is an open structure, which can play a guiding role when installing the graphite base 1, making it convenient for the bottom end of the electrode insertion hole 4 to be inserted into the conductive electrode.
[0036] A graphite connecting post 6 is integrally provided on the top of the graphite base 1, which is coaxially arranged with the electrode insertion hole 4. An external thread is provided on the outer periphery of the graphite connecting post 6. A graphite connecting sleeve 7 is welded to the bottom of the hollow silicon core 2. An internal thread is provided on the inner surface of the graphite connecting sleeve 7. The graphite connecting sleeve 7 is threadedly connected to the graphite connecting post 6.
[0037] The top of the hollow silicon core 2 is integrally provided with a frustum-shaped overlapping platform 8. In this embodiment, the overlapping platform 8 is a frustum-shaped structure. An overlapping hole 9 matching the overlapping platform 8 is opened at both ends of the horizontal silicon plate 3, and the positions of the two overlapping holes 9 on one horizontal silicon plate 3 correspond to the positions of the two pairs of hollow electrodes.
[0038] Furthermore, a concave groove 5 is provided in the middle of the overlapping platform 8 along the circumferential direction, and the top height of the concave groove 5 is higher than the top surface height of the horizontal silicon plate 3.
[0039] Furthermore, a first vent 10 is provided on the side wall of the graphite base 1, connecting the electrode insertion hole 4 and the outside of the graphite base 1; a second vent 11 is provided at the top center of the overlapping platform 8, connecting the inside of the hollow silicon core 2 and the outside of the hollow silicon core 2; by providing vents, when the electrode insertion hole 4 and the inside of the hollow silicon core 2 expand due to heat, the gas can be vented out through the vents, thus playing a buffering role; at the same time, when the furnace is opened, the vents can be used to achieve replacement without leaving dead corners, and the inside of the installed hollow silicon core 2 is not subjected to force, further ensuring the stability of the installation of the hollow silicon core 2.
[0040] Job Description:
[0041] In use of the embodiment, first, the graphite base 1 is inserted on the conductive electrode through the electrode insertion hole 4, the bottom end of the hollow silicon core 2 is screwed with the graphite connecting column 6 on the graphite base 1 through the graphite connecting sleeve 7, and the hollow silicon core 2 is kept in a vertical state; the top end of the pair of hollow silicon cores 2 is overlapped with a horizontal silicon plate 3 by inserting the overlapping table 8 at the top end of the hollow silicon core 2 into the corresponding overlapping hole 9, and a "U" shaped loop is formed; in the overlapping process, the top end of the pair of hollow silicon cores 2 can be kept in a horizontal state without installation stress by rotating the hollow silicon core 2, thereby ensuring that the horizontal silicon plate 3 is in a horizontal state and is in good contact with the overlapping table 8. Π
[0042] In the embodiment, the overlapping table 8 is set as a conical table structure, compared with a cylindrical structure, the contact area at the overlapping position is increased, which not only facilitates the alignment and insertion with the overlapping hole 9 on the horizontal silicon plate 3, simplifies the installation process, improves the work efficiency, but also improves the stability of the overlapping, effectively avoids the occurrence of the phenomenon of the furnace being reversed, and can also avoid the situation that the high temperature of the silicon core, the damage of the silicon core and even the melting of the silicon core caused by the current overload due to the small contact area, which affects the stable operation of the reduction furnace. In order to further improve the stability of the overlapping, the recessed groove 5 is arranged in the middle of the overlapping table 8 in the embodiment, when the upper part of the hollow silicon core 2 is disturbed by airflow and the horizontal silicon plate 3 is inclined, the recessed groove 5 can limit the horizontal silicon plate 3, thereby ensuring that the horizontal silicon plate 3 will not be blown off by the airflow.
[0043] The hollow silicon core 2 has the same weight as the solid silicon core before the improvement under the same working condition as before the improvement since the end of 2018, but the diameter is much larger than that of the solid silicon core, and the surface area is doubled, thereby obtaining the basic conditions for the rapid growth of the polycrystalline rod, thereby reducing the use cost and improving the output rate of the product; the growth rate of the embodiment can be increased by 9.68%; at the same time, the increase of the diameter also strengthens the strength of the silicon core, and the stable overlapping structure makes the furnace not reversed until now, thereby providing reliable technical support for the industrial application of the hollow silicon core 2.
[0044] The above only describes the preferred embodiment of the utility model, and does not limit the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A hollow silicon core overlapping structure for a polycrystalline silicon reduction furnace, characterized in that, The graphite base, the hollow silicon core and the horizontal silicon plate are included. An electrode insertion hole matched with the conductive electrode is formed at the bottom end of the graphite base, and the electrode insertion hole is inserted on the conductive electrode. A graphite connecting column coaxially arranged with the electrode insertion hole is integrally arranged at the top end of the graphite base, and an external thread is arranged on the outer periphery of the graphite connecting column. The bottom end of the hollow silicon core is threadedly connected with the graphite connecting column. A conical lap platform is integrally arranged at the top end of the hollow silicon core, and a lap hole matched with the lap platform is formed at each end of the horizontal silicon plate, and the positions of the two lap holes on one horizontal silicon plate correspond to the positions of the pair of hollow electrodes.
2. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein A concave groove is formed at the middle part of the lap platform along the circumferential direction, and the top end height of the concave groove is higher than the top surface height of the horizontal silicon plate.
3. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein A first exhaust hole communicating between the electrode insertion hole and the outside of the graphite base is formed on the side wall of the graphite base.
4. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein A second exhaust hole communicating between the inside of the hollow silicon core and the outside of the hollow silicon core is formed at the top center of the lap platform.
5. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein A graphite connecting sleeve is welded at the bottom end of the hollow silicon core, an internal thread is arranged on the inner surface of the graphite connecting sleeve, and the graphite connecting sleeve is threadedly connected with the graphite connecting column.
6. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein The hole diameter and hole depth of the electrode insertion hole are matched with the diameter and height of the conductive electrode respectively.
7. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1 or 6, characterized in that, The opening end of the electrode insertion hole is in an open structure.
8. The hollow silicon core lapping structure of a polysilicon reduction furnace according to claim 1, wherein, The lap platform is in a conical platform structure.