A lower baffle lifting device of an ingot casting furnace
By improving the design of the lower baffle lifting device of the ingot furnace, the problem of easy deformation and jamming of the lower baffle was solved, realizing efficient directional solidification and high-quality purification of polysilicon, and improving the reliability of the equipment and the yield of polysilicon.
Patent Information
- Application Number
- CN202521713101.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-13
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-08-13
AI Technical Summary
The existing ingot furnace lower baffle structure is prone to deformation and jamming, which makes directional solidification control difficult, causes frequent failures, and results in a low polysilicon yield.
The ingot furnace lower baffle lifting device includes a lifting support assembly, an inner cylinder cover, an inner cylinder body, a lower furnace cover, a lifting seat assembly, a servo motor, a lifting assembly, and a lower baffle assembly. Combined with a three-layer overflow cotton insulation, water circulation cooling, and a vacuum pumping system, it achieves smooth lifting and lowering of the lower baffle and temperature gradient control.
It improves the control precision of directional solidification of polycrystalline silicon, extends the service life of equipment, and enhances the purification quality and yield of polycrystalline silicon.
Smart Images
Figure CN224678213U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of polycrystalline silicon ingot casting process, and in particular to a lifting device for the lower baffle of an ingot casting furnace. Background Technology
[0002] The ingot casting furnace is a specialized piece of equipment for polycrystalline silicon ingot casting. The ingot casting process involves complex physical and chemical changes, including melting, impurity removal, directional solidification, and purification of silicon material of a certain purity. Because the melting point of polycrystalline silicon is around 1415℃, the silicon material needs to be heated to approximately 1500℃ inside the ingot casting furnace to achieve complete melting. Simultaneously, to achieve impurity removal and purification, the ingot casting furnace needs to be evacuated and inert gas circulated throughout the casting process. The directional solidification process of polycrystalline silicon requires the bottom insulation layer baffle to open after the silicon material has completely melted, creating a temperature gradient. The polycrystalline silicon then undergoes directional solidification from the inside out and from the bottom up. Therefore, the opening and closing of the bottom baffle is crucial for directional solidification. For a long time, the market has used a method where the lower baffle of the internal thermal field is set up as a linkage mechanism connected to an external motor, and it is opened and closed in a louver-like manner. This can easily cause the bottom to dissipate heat too quickly, resulting in a low yield of polycrystalline silicon produced by directional solidification. Moreover, the complex linkage structure is easily deformed and jammed in the environment of sudden cooling and heating, which leads to frequent failures of the lower baffle and frequent repair work to replace the lower baffle assembly. Utility Model Content
[0003] The technical problem this utility model aims to solve is to overcome the shortcomings of existing technologies by proposing a lower baffle lifting device for ingot furnaces, which addresses the problems of difficulty in controlling the directional solidification process of polycrystalline silicon and frequent lower baffle failures in current equipment.
[0004] To solve the above technical problems, the technical solution of this utility model is as follows: A lower baffle lifting device for an ingot casting furnace includes a lifting support assembly, an inner cylinder cover, an inner cylinder body, a lower furnace cover, a lifting seat assembly, a servo motor, a lifting mechanism assembly, and a lower baffle assembly. The lower baffle assembly is mounted on the upper end of the lifting support assembly. The inner cylinder body is located inside the lower flange of the lower furnace body, and the inner cylinder cover is mounted on the upper end of the inner cylinder body. The lower furnace cover is located outside the lower flange of the lower furnace body. The lifting seat assembly is located at the bottom of the lower furnace cover. The servo motor and the lifting mechanism assembly are mounted on the base plate of the lifting seat assembly, and the lifting mechanism assembly is connected to the output end of the servo motor. The lifting shaft of the lifting support assembly passes sequentially through the inner cylinder body, the lower furnace body, and the lower furnace cover, and the lifting shaft is connected to the lifting mechanism assembly via a connecting plate. A thermocouple assembly penetrates from the outside of the lower furnace body to the inside of the lower baffle assembly, and a thermocouple vacuum assembly is installed outside the lower furnace body.
[0005] Furthermore, the inner cylinder and the inner cylinder cover are covered with three layers of overflow cotton, and the height of the inner cylinder corresponds to the maximum overflow volume of the silicon liquid that can be accommodated inside the lower furnace body.
[0006] Furthermore, the lower furnace cover is internally provided with a water inlet, a water channel, and a water outlet, which are connected to circulating water to form a cooling system; a furnace cover sealing ring is provided between the lower furnace cover and the lower furnace body; two linear bearings are provided inside the lower furnace cover, and two lifting shafts are respectively inserted into the interior of the two linear bearings; two welded bellows are provided between the lower furnace cover and the connecting plate, and the two welded bellows are respectively sleeved on the outside of the two lifting shafts. A flange sealing ring is provided at the upper end of the welded bellows, and a shaft end sealing ring is provided at the lower end of the welded bellows.
[0007] Furthermore, the lifting seat assembly is installed at the lower end of the lower furnace cover, and the lifting assembly includes a lead screw, which is connected to the output end of the servo motor. A threaded sleeve is fixedly connected to the top of the connecting plate, and the lead screw and the threaded sleeve form a threaded pair. A bearing seat is provided at the bottom of the lower furnace cover, and the top of the lead screw is connected to a bearing seat provided with a ball bearing and a snap ring.
[0008] Furthermore, the thermocouple assembly passes sequentially through the lower furnace cover, lower furnace body, inner cylinder, inner cylinder cover, and lower baffle assembly. The lower furnace cover is provided with a vacuum interface connected to the thermocouple vacuum assembly, and a movable stop is provided on the bottom plate of the lifting seat assembly.
[0009] Furthermore, the protective plate assembly is installed at the bottom of the lower furnace body and on the outside of the lifting seat assembly and the lower furnace cover.
[0010] Compared with the prior art, the advantages of this utility model are: The lower baffle lifting mechanism of this utility model has the characteristics of simple structure, excellent heat insulation and high vacuum efficiency. It adopts a simple servo motor to control the up and down movement of the lifting machine, which drives the lower baffle in the middle of the bottom of the insulation layer to realize the opening and closing process. The interior adopts three layers of overflow cotton and double heat insulation and transmission protection of the inner cylinder. Water circulation is added to the limited space of the lower cover plate for heat insulation, ensuring the smooth operation of the lifting mechanism and conforming to the directional solidification process from the center to the outside and from the bottom to the top. Attached Figure Description
[0011] Figure 1 This is an isometric drawing of a lower baffle lifting device for an ingot furnace, as per utility model specifications. Figure 2 This is a top view of a lower baffle lifting device for an ingot furnace according to the present invention; Figure 3 This is a cross-sectional view (AA) of a lower baffle lifting device for an ingot furnace according to this utility model. Figure 4 This is a BB cross-sectional view of a lower baffle lifting device for an ingot furnace according to this utility model; Figure 5 This is a cross-sectional view of the internal water passage of the lower furnace cover of a lower baffle lifting device for an ingot furnace according to this utility model; The specific reference numerals in the attached figures are as follows: 1 Lifting bracket assembly, 101 Lifting shaft, 2 Inner cylinder cover, 3 Inner cylinder body, 4 Lower furnace body, 5 Lower furnace cover, 501 Furnace cover sealing ring, 502 Linear bearing, 503 Flange sealing ring, 504 Welded bellows, 505 Shaft end sealing ring, 506 Connecting plate, 507 Water inlet, 508 Water channel, 509 Water outlet, 6 Lifting seat assembly, 601 Movable stop block, 7 Thermocouple vacuum assembly, 8 Servo motor, 9 Lifting machine assembly, 901 Support base, 902 Snap ring, 903 Ball bearing, 904 Screw sleeve, 905 Lead screw, 10 Lower baffle assembly, 11 Thermocouple assembly, 12 Protective plate assembly. Detailed Implementation
[0012] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.
[0013] Figures 1 to 5 As shown, a lower baffle lifting device for an ingot furnace includes a lifting support assembly 1, an inner cylinder cover 2, an inner cylinder body 3, a lower furnace cover 5, a lifting seat assembly 6, a servo motor 8, a lifting mechanism assembly 9, and a lower baffle assembly 10. The lower baffle assembly 10 is installed at the upper end of the lifting support assembly 1. The inner cylinder body 3 is located inside the lower flange of the lower furnace body 4, and the inner cylinder cover 2 is installed at the upper end of the inner cylinder body 3. The lower furnace cover 5 is located outside the lower flange of the lower furnace body 4. The lifting seat assembly 6 is located at the bottom of the lower furnace cover 5. The servo motor 8 and the lifting mechanism assembly 9 are installed on the base plate of the lifting seat assembly 6. The lifting shaft 101 of the lifting support assembly 1 passes through the inner cylinder body 3, the lower furnace body 4, and the lower furnace cover 5 in sequence and is connected to the lifting mechanism assembly 9 through a connecting plate 506, driving the lower baffle assembly 10 to move up and down. Thermocouple assembly 11 penetrates from the outside of the lower furnace body 4 into the lower baffle assembly 10 to monitor the internal temperature. A thermocouple vacuum assembly 11 is installed on the outside to evacuate the pipeline.
[0014] Three layers of overflow cotton are laid on the outside of the inner cylinder 3 and the inner cylinder cover 2 to provide heat insulation and transmission protection for the part of the lifting support assembly 1 and the thermocouple assembly 11 located inside the lower furnace body 4. The height of the inner cylinder 3 is set according to the maximum overflow volume of silicon liquid that the lower furnace body 4 can accommodate, to prevent silicon liquid from overflowing and causing safety accidents.
[0015] The lower furnace cover 5 is equipped with a water inlet 507, a water channel 508, and a water outlet 509, which are connected to circulating water to form a cooling system to block the internal heat field. A furnace cover sealing ring 501 is installed between the lower furnace cover 5 and the lower furnace body 4 to achieve a sealed installation. Two linear bearings 502 installed inside the lower furnace cover 5 provide support and guidance for the lifting and lowering movement of the two lifting shafts 101. Two welded bellows 504 are installed between the lower furnace cover 5 and the connecting plate 506 and outside the two lifting shafts 101. The flanges at the upper and lower ends of the welded bellows 504 are equipped with flange sealing rings 503 and shaft end sealing rings 505 to achieve a sealed installation. The welded bellows 504 can be stretched and shortened while maintaining a seal.
[0016] The lifting seat assembly 6 is installed at the lower end of the lower furnace cover 5. The lifting machine assembly 9 is set on the base plate of the lifting seat assembly 6 and connected to the servo motor 8. The lead screw 905 and the screw sleeve 904 installed on the connecting plate 506 form a threaded pair. The connecting plate 506 and the lifting shaft 101 rise and fall with the forward and reverse rotation of the lead screw 905. The top of the lead screw 905 is connected to the bearing seat 901, which is equipped with a ball bearing 903 and a snap ring 902, which plays a supporting role at the end of the lead screw 905 and ensures that the lifting movement is stable.
[0017] Thermocouple assembly 11 is a temperature monitoring sensor at the bottom of the internal thermal field. It needs to pass through the lower furnace cover 5, lower furnace body 4, inner cylinder 3, inner cylinder cover 2 and lower baffle assembly 10 in sequence and be fixed as a whole. The lower furnace cover 5 is provided with a vacuum interface that connects to the thermocouple vacuum assembly 7. The external vacuum unit performs vacuuming through the thermocouple vacuum assembly 7. Adding this vacuuming pipeline can improve the vacuuming efficiency of the ingot furnace. In order to facilitate the installation of the long thermocouple assembly 11, a movable stop 601 is provided on the base plate of the lifting seat assembly 6. It is installed after the thermocouple assembly 11 is installed, which can also serve to reinforce the base plate.
[0018] The protective plate assembly 12 is installed at the bottom of the lower furnace body 4 and on the outside of the lifting seat assembly 6 and the lower furnace cover 5, serving as a safety protection function.
[0019] In the specific implementation of this utility model: After the silicon ingot is removed from the previous ingot casting process, before the next ingot casting process begins, the servo motor 8 is rotated forward to drive the lead screw 905 to rotate forward, driving the lifting support assembly 1 to rise until the lower baffle assembly 10 installed at the top closes with the bottom baffle. After the new round of silicon material loading is completed and the vacuum is evacuated, heating begins to raise the temperature for the ingot casting process. When the silicon material is completely melted, the program controls the servo motor 8 to rotate in reverse, driving the lead screw 905 to rotate in reverse, thereby driving the lower baffle assembly 10 installed on the lifting support assembly 1 to open downward at a certain speed. By controlling the opening timing and speed of the lower baffle assembly 10, the temperature is adjusted to form a certain temperature gradient, promoting the directional solidification and crystallization process of polycrystalline silicon from the center outwards and from the bottom up. After the directional solidification process is completed, the servo motor 8 is rotated forward again to drive the lower baffle assembly 10 to close, completing one ingot casting process.
[0020] The purpose of this invention is to simplify the structure of the lower baffle lifting device, increase the pipeline to improve vacuuming efficiency and increase the water circuit to block the influence of the thermal field, thereby extending the service life of the components. At the same time, the lower baffle component is improved from a fully hinged, large-opening and closing type to a bottom middle partial baffle that opens and closes up and down, so that the internal thermal field and temperature gradient are more in line with the polycrystalline silicon directional solidification process, thereby improving the polycrystalline silicon purification quality and yield.
[0021] The above are merely preferred embodiments of this utility model. It should be noted that the above preferred embodiments should not be considered as limitations on this utility model, and the scope of protection of this utility model should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.
Claims
1. A lifting device for the lower baffle of a casting furnace, characterized in that, The system includes a lifting support assembly (1), an inner cylinder cover (2), an inner cylinder body (3), a lower furnace cover (5), a lifting seat assembly (6), a servo motor (8), a lifting mechanism assembly (9), and a lower baffle assembly (10). The lower baffle assembly (10) is installed at the upper end of the lifting support assembly (1). The inner cylinder body (3) is located inside the lower flange of the lower furnace body (4), and the inner cylinder cover (2) is installed at the upper end of the inner cylinder body (3). The lower furnace cover (5) is located outside the lower flange of the lower furnace body (4), and the lifting seat assembly (6) is located at the bottom of the lower furnace cover (5). The servo motor (8) The lifting assembly (9) is installed on the base plate of the lifting seat assembly (6), and the lifting assembly (9) is connected to the output end of the servo motor (8) for transmission. The lifting shaft (101) of the lifting bracket assembly (1) passes through the inner cylinder (3), the lower furnace body (4), and the lower furnace cover (5) in sequence. The lifting shaft (101) is connected to the lifting assembly (9) through the connecting plate (506). The thermocouple assembly (11) penetrates from the outside of the lower furnace body (4) to the inside of the lower baffle assembly (10). A thermocouple vacuum assembly (7) is provided on the outside of the lower furnace body (4).
2. The ingot furnace lower baffle lifting device according to claim 1, characterized in that, The inner cylinder (3) and the inner cylinder cover (2) are covered with three layers of overflow cotton. The height of the inner cylinder (3) corresponds to the maximum overflow silicon liquid volume that the lower furnace body (4) can accommodate.
3. The ingot furnace lower baffle lifting device according to claim 1, characterized in that, The lower furnace cover (5) is provided with a water inlet (507), a water channel (508) and a water outlet (509). The water inlet (507), water channel (508) and water outlet (509) are connected to circulating water to form a cooling system. A furnace cover sealing ring (501) is provided between the lower furnace cover (5) and the lower furnace body (4). Two linear bearings (502) are provided inside the lower furnace cover (5), and two lifting shafts (101) are respectively inserted into the two linear bearings (502). Two welded corrugated pipes (504) are provided between the lower furnace cover (5) and the connecting plate (506). The two welded corrugated pipes (504) are respectively sleeved on the outside of the two lifting shafts (101). A flange sealing ring (503) is provided at the upper end of the welded corrugated pipe (504), and a shaft end sealing ring (505) is provided at the lower end of the welded corrugated pipe (504).
4. The ingot furnace lower baffle lifting device according to claim 1, characterized in that, The lifting seat assembly (6) is installed at the lower end of the lower furnace cover (5). The lifting assembly (9) includes a lead screw (905), which is connected to the output end of the servo motor (8). A threaded sleeve (904) is fixedly connected to the top of the connecting plate (506). The lead screw (905) and the threaded sleeve (904) form a threaded pair. A bearing seat (901) is provided at the bottom of the lower furnace cover (5). The top of the lead screw (905) is connected to the bearing seat (901) which is provided with a ball bearing (903) and a snap ring (902).
5. The ingot furnace lower baffle lifting device according to claim 1, characterized in that, The thermocouple assembly (11) passes through the lower furnace cover (5), the lower furnace body (4), the inner cylinder (3), the inner cylinder cover (2), and the lower baffle assembly (10) in sequence. The lower furnace cover (5) is provided with a vacuum interface connected to the thermocouple vacuum assembly (7). The bottom plate of the lifting seat assembly (6) is provided with a movable stop (601).
6. The ingot furnace lower baffle lifting device according to claim 1, characterized in that, The bottom of the lower furnace body (4) and the outside of the lifting seat assembly (6) and the lower furnace cover (5) are equipped with a protective plate assembly (12).