Large-size sapphire ky method graphite heat field multi-zone direct current power supply adapting device

Abstract

The application discloses a large-size sapphire KY method graphite heat field multi-zone direct current power supply adapting device, which comprises a furnace body, the inside of the furnace body is sequentially provided with an upper heating body, a middle heating body and a lower heating body from top to bottom, heat insulation baffles are arranged at the gaps of the upper heating body, the middle heating body and the lower heating body, a plurality of conductive electrode sleeves are arranged in the inside of the upper heating body, the middle heating body and the lower heating body, a limiting rib is arranged at the top end of the inner wall of the upper heating body, the upper heating body, the middle heating body and the lower heating body are connected with the furnace body through heat insulation assemblies, and a height adjusting assembly is arranged at the bottom end of the furnace body. The three heating bodies are connected with independent direct current circuits through the embedded conductive electrode sleeves, the independent adjustment of the heating powers of the upper, middle and lower three zones is not interfered with each other, and the heat can be dynamically distributed according to the temperature field gradient required by different stages of large-size sapphire crystal growth.

Description

Technical Field

[0001] This invention relates to the field of large-size sapphire manufacturing, specifically to a DC power supply adapter for large-size sapphire KY process graphite thermal field multi-zone. Background Technology

[0002] The KY method is currently the mainstream process for preparing large-size sapphire single crystals. The quality of the crystal is highly dependent on the uniformity and controllability of the temperature field of the graphite thermal field in the furnace. At present, most of the graphite heating systems of similar single crystal furnaces adopt an integrated graphite heating element with a single AC power supply mode. The structure is simple to assemble and can meet the basic heating requirements in the production of small-size sapphire crystals.

[0003] In the iterative production of large-size sapphire single crystals, existing structures have exposed several unavoidable technical shortcomings. First, the introduction of AC current into the graphite heating element results in a significant skin effect, with inconsistent heating power between the surface and core of the heating element, leading to uneven heating of the heating body. Long-term high-temperature use can easily cause localized ablation and damage, shortening the service life of the graphite components. Second, the integrated heating element cannot be separated along the furnace axis for independent temperature control. The upper, middle, and lower parts of the furnace can only output heat synchronously, making it impossible to adjust the heat output of each zone individually according to the process requirements of different crystal growth stages. The axial temperature difference in the furnace is difficult to reduce effectively, and the temperature field gradient cannot accurately match the crystal growth requirements. Third, traditional heating elements lack interlayer physical thermal insulation structures, and heat from the upper and lower regions interferes with each other through heat conduction and heat convection, further exacerbating the temperature field disorder. Fourth, the lack of a reliable central limiting structure inside the furnace thermal field makes the crucible and temperature measuring components prone to radial offset and eccentricity, resulting in asymmetrical heating and easily inducing quality defects such as excessive crystal stress, cracking, shape distortion, and excessive dislocation density.

[0004] Meanwhile, conventional single crystal furnaces are fixed floor-mounted installation structures, which cannot be adjusted for levelness based on the flatness of the installation base, nor can the equipment's working height and maintenance posture be flexibly adjusted. Equipment debugging and the disassembly and maintenance of internal heating components are difficult, and the overall machine's adaptability to operating conditions is insufficient. All of these problems together restrict the improvement of yield and process stability of large-size, high-quality sapphire single crystals. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter.

[0006] The technical solution adopted by this invention to solve its technical problem is: a large-size sapphire KY method graphite thermal field multi-zone DC power supply adapter device, including a furnace body. The furnace body has an upper heating element, a middle heating element, and a lower heating element arranged sequentially from top to bottom. Heat insulation baffles are arranged at the gaps between the upper heating element, the middle heating element, and the lower heating element. Multiple conductive electrode sleeves are arranged inside the upper heating element, the middle heating element, and the lower heating element. Limiting ribs are arranged at the top of the inner wall of the upper heating element. The upper heating element, the middle heating element, and the lower heating element are connected to the furnace body through a heat insulation component. A height adjustment component is arranged at the bottom of the furnace body.

[0007] Furthermore, the heat insulation assembly includes an upper heat insulation sleeve, a middle heat insulation sleeve, and a lower heat insulation sleeve respectively disposed on the outer wall of the upper section heating element, the middle section heating element, and the lower section heating element. The top of the outer wall of the upper heat insulation sleeve, the middle heat insulation sleeve, and the lower heat insulation sleeve are all provided with a limiting ring plate, and the limiting ring plate is connected to the furnace body through a furnace retaining ring.

[0008] Furthermore, the heat insulation baffle is tightly fitted between the upper section heating element, the middle section heating element and the lower section heating element, and a gap is provided at the center of the heat insulation baffle.

[0009] Furthermore, the limiting ribs are arranged equidistantly along the inner wall of the upper heating element, and the limiting ribs extend from top to bottom into the interior of the lower heat insulation sleeve.

[0010] Furthermore, the height adjustment component includes a furnace body base disposed at the bottom of the furnace body, a rotating bracket rotatably connected to the outer wall of the furnace body base, lifting hydraulic cylinders disposed at the top of both sides of the rotating bracket, the output end of the lifting hydraulic cylinders passing through the rotating bracket, support leg sleeves disposed at the bottom of both sides of the rotating bracket, telescopic support legs slidably connected inside the support leg sleeves, a fixed seat disposed at the bottom of the telescopic support legs, and a rotating fixing component disposed at the center of the front surface of the rotating bracket.

[0011] Furthermore, the rotating bracket has multiple fixing grooves circumferentially formed at its edge, and the output end of the rotating fixing component matches the fixing grooves.

[0012] Furthermore, the upper, middle, and lower heating elements are each independently connected to a DC power supply circuit via their respective embedded conductive electrode sleeves. The three DC power supply circuits are electrically isolated and their power outputs do not interfere with each other. The DC current flows evenly through the entire cross-section of the heating element to eliminate the skin effect of AC power supply.

[0013] Furthermore, the furnace body is equipped with temperature acquisition units corresponding to the upper, middle and lower temperature zones. Each temperature acquisition unit forms a signal closed loop with the control system of the corresponding DC power supply circuit, and dynamically adjusts the DC output power of the corresponding upper section heating element, middle section heating element and lower section heating element according to the temperature field gradient requirements of each stage of crystal growth.

[0014] Furthermore, the upper insulation sleeve, middle insulation sleeve, lower insulation sleeve, and the insulation baffles set between the layers together constitute a radial and axial bidirectional thermal barrier system; the insulation baffles block the longitudinal heat conduction and furnace convection heat transfer between adjacent temperature zones, and each insulation sleeve blocks the radial heat radiation and heat conduction of the corresponding temperature zone, so that the three temperature zones form an independent closed temperature control unit.

[0015] Furthermore, multiple circumferentially distributed limiting ribs form a central limiting channel that runs through the entire cavity. After the crucible and temperature measuring element are assembled along this channel, they maintain coaxiality with the upper, middle, and lower heating elements, ensuring that the crystal growth center coincides with the central axis of the thermal field and guaranteeing uniform and symmetrical radial heating.

[0016] The beneficial effects of this invention are: The structure adopts a combination of an axial three-section split graphite heating element with layered heat-insulating baffles and an outer independent heat-insulating sleeve. At the physical level, the thermal field is divided into three independent temperature zones that are thermally isolated from each other, effectively blocking heat crosstalk between zones. Combined with a multi-zone DC independent power supply method, the AC skin effect is eliminated from the source. The graphite heating element cross-section has better heating consistency and lower heat loss, which greatly extends the service life of graphite thermal field consumables.

[0017] The three heating elements are connected to independent DC circuits via embedded conductive electrode sleeves, enabling independent adjustment of heating power in the upper, middle, and lower zones without interference. This allows for dynamic heat distribution according to the temperature gradient required at different stages of large-size sapphire crystal growth, greatly reducing the axial and radial temperature difference in the furnace, optimizing the symmetry of the thermal field inside the furnace, and reducing defects such as cracking, excessive internal stress, and growth deformation caused by uneven temperature field in the crystal. This significantly improves the quality and yield of single crystal products.

[0018] The through-type circumferentially arranged limiting ribs can center and limit the crucible and temperature measuring components in the furnace throughout the process, avoiding the eccentricity of the core components under high temperature operation, ensuring that the crystal growth axis coincides with the central axis of the thermal field, further ensuring the uniformity and stability of the heating environment, and reducing the negative impact of human assembly errors on the crystal growth results.

[0019] The bottom integrates a height adjustment component that can rotate, be hydraulically lifted, and level at multiple points. It can flexibly change the furnace working height through the hydraulic cylinder to adapt to different process docking requirements, and can also use telescopic outriggers to compensate for ground flatness errors to ensure that the equipment is placed horizontally. The rotating bracket, together with the gear fixing groove and locking parts, can lock the furnace posture at multiple angles, which greatly facilitates the inspection, disassembly and assembly of the internal heating element, heat insulation component and electrode structure, and reduces the difficulty of later operation and maintenance of the equipment.

[0020] The outer heat insulation sleeve, together with the furnace baffle ring and the limiting ring plate, completes the overall hanging and positioning of the heating element. While blocking the heat from being conducted to the furnace shell and reducing energy consumption, it also restrains the settlement and displacement of the heating structure under high temperature conditions. The entire thermal field assembly structure has stronger stability, high consistency of temperature field state during long-term continuous production, and better process repeatability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the present invention.

[0022] Figure 2 yes Figure 1 Detailed view of the connection structure in the cross-section at the bottom position.

[0023] Figure 3 yes Figure 1 Detailed diagram of the internal connection structure.

[0024] Figure 4 yes Figure 1 Detailed cross-sectional view of the furnace body's connection structure.

[0025] Figure 5 yes Figure 1 Detailed cross-sectional view of the connection structure of the height adjustment component.

[0026] Figure 6 yes Figure 4 A top-down view of the connection structure details.

[0027] Figure 7 yes Figure 1 Detailed diagram of the connection structure of the middle limiting rib.

[0028] Explanation of reference numerals in the attached drawings: 1. Furnace body; 2. Furnace inner baffle ring; 3. Upper heating element; 4. Middle heating element; 5. Lower heating element; 6. Insulation baffle; 7. Upper insulation sleeve; 8. Middle insulation sleeve; 9. Lower insulation sleeve; 10. Conductive electrode sleeve; 11. Limiting rib; 12. Furnace body base; 13. Rotating bracket; 14. Lifting hydraulic cylinder; 15. Leg sleeve; 16. Telescopic leg; 17. Fixed seat; 18. Rotating fixing component. Detailed Implementation

[0029] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0030] See Figures 1-7 This is a schematic diagram of the structure of the present invention, a multi-zone DC power supply adapter for a large-size sapphire KY method graphite hot zone, including a furnace body 1. The furnace body 1 serves as the main pressure-bearing and protective shell of the entire single crystal growth hot zone equipment. It is a closed cavity structure with overall structural characteristics of high temperature resistance, deformation resistance, and thermal insulation protection. The furnace body 1 is mainly used to integrate and assemble the internal heating structure, thermal insulation structure, conductive structure, and temperature control structure, forming a comprehensive protective enclosure for all core hot zone components inside, isolating the external ambient temperature, airflow, and dust from interfering with the crystal growth temperature field inside the furnace. At the same time, it bears the heat load generated by the high-temperature operation inside the equipment, ensuring the airtightness and stability of the furnace cavity environment during the growth of large-size sapphire single crystals, and providing basic structural support for the stable operation of the zoned temperature-controlled hot zone.

[0031] The interior of furnace body 1 is arranged from top to bottom with an upper heating element 3, a middle heating element 4, and a lower heating element 5. All three heating elements are made of high-purity graphite. The three heating elements are arranged independently in layers along the axial direction of the furnace body 1 cavity, forming the core axial heating temperature field inside the furnace. The three heating elements are set up independently in separate zones, abandoning the traditional one-piece graphite heating structure. This allows them to correspond to three independent temperature control zones in the upper, middle, and lower layers of the heating field, each receiving electrical energy from an independent DC power supply and generating Joule heat. This achieves independent axial zone heating of the heating field, structurally matching the core process requirements of multi-zone DC zone temperature control. It effectively adapts to the wide range and uniform temperature field environment required for the growth of large-size sapphire crystals, solving the structural drawbacks of traditional whole heating methods that cannot be zoned for temperature adjustment.

[0032] Heat insulation baffles 6 are installed at the gaps between the upper heating element 3, the middle heating element 4, and the lower heating element 5. The heat insulation baffles 6 achieve thermal isolation and structural separation between adjacent heating elements, avoiding crosstalk between the three temperature fields. Multiple conductive electrode sleeves 10 are installed inside the upper heating element 3, the middle heating element 4, and the lower heating element 5. The conductive electrode sleeves 10 are embedded conductive connection structures, fixedly embedded in the preset installation positions of each graphite heating element, and closely fit and conduct with the heating element body. The conductive electrode sleeves 10 are mainly used to achieve stable connection between the external DC power supply line and each heating element, regulate the power input path, increase the conductive contact area, reduce the conductive contact resistance, and avoid problems such as loose electrode contact, arcing, and uneven heating under high temperature conditions. This ensures that each heating element can independently, stably, and uniformly receive DC power, and ensures the stability of zoned heating.

[0033] The upper heating element 3 has a limiting rib 11 at the top of its inner wall, which is used to limit and correct the axial and circumferential positioning of the internal components such as the crucible, temperature measuring components, and flow guiding structure inside the furnace. The upper heating element 3, the middle heating element 4, and the lower heating element 5 are connected to the furnace body 1 through a heat insulation component. The heat insulation component achieves insulation and positioning between the heating element and the furnace shell, preventing heat conduction to the furnace body and causing overheating damage to the equipment shell. At the same time, it achieves overall fixed positioning of the heating structure. The bottom of the furnace body 1 is equipped with a height adjustment component, which is used to adjust the installation height and level of the furnace equipment as a whole, adapting to different crystal growth process conditions and different supporting equipment assembly height requirements, improving equipment installation adaptability and process debugging convenience.

[0034] The heat insulation components include an upper heat insulation sleeve 7, a middle heat insulation sleeve 8, and a lower heat insulation sleeve 9, which are respectively installed on the outer walls of the upper heating element 3, the middle heating element 4, and the lower heating element 5. The upper heat insulation sleeve 7, the middle heat insulation sleeve 8, and the lower heat insulation sleeve 9 are all made of high-strength, high-temperature resistant heat insulation material. They completely cover the outer side walls of the upper heating element 3, the middle heating element 4, and the lower heating element 5, and are fitted to the outer walls of each heating element. The three sets of heat insulation sleeves independently correspond to the heating elements in each zone, which can block the heat radiated and conducted outward from each heating element in all directions, effectively blocking the heat from the heating element to diffuse and transfer to the furnace body 1 shell, avoiding problems such as deformation, aging, and decreased sealing of the furnace body due to long-term high-temperature heating. At the same time, it realizes the external heat insulation isolation of the three heating temperature zones, reduces heat leakage and heat crosstalk between zones, retains the effective heat energy in the furnace to the maximum extent, improves the heat energy utilization rate, and ensures the accuracy of zone temperature control. Limiting ring plates are provided at the top of the outer walls of the upper insulation sleeve 7, the middle insulation sleeve 8, and the lower insulation sleeve 9. The limiting ring plates are integral annular flange structures, which are fixedly connected to the top of the corresponding insulation sleeves as a whole structure. The annular plate surface is flat and the force is uniform. The limiting ring plates are connected to the furnace body 1 through the furnace retaining ring 2. The furnace retaining ring 2 is fixedly embedded in the inner side wall of the furnace body 1 at the preset installation step position. It is a fixed positioning and bearing structure that can engage and limit the limiting ring plates. It forms vertical bearing and circumferential positioning constraints on the three sets of insulation sleeves and the heating elements wrapped inside, restricting the insulation sleeves and heating elements from vertical settlement, radial displacement and circumferential rotation under high temperature working environment. It ensures the assembly coaxiality and overall regularity of the layered heating structure inside the furnace, maintains the stable assembly state of the thermal field structure for a long time, and avoids temperature field distortion caused by structural misalignment.

[0035] The heat insulation baffle 6 is tightly fitted between the upper heating element 3, the middle heating element 4, and the lower heating element 5, with a gap in the center. The heat insulation baffle 6 is a ring-shaped heat insulation structure, precisely fitted and fixed at the joint gap between each pair of adjacent heating elements, completely filling the assembly gap between adjacent heating elements. This achieves physical heat insulation isolation between adjacent temperature control areas. The heat insulation baffle 6 effectively blocks longitudinal heat conduction and convection heat transfer between adjacent heating elements, preventing heat from diffusing downwards from the upper temperature zone, heat from flowing upwards from the lower temperature zone, and heat from flowing upwards from the middle temperature zone. The problem of bidirectional heat crosstalk in the temperature zones is completely solved, achieving complete independence of the temperature fields in the upper, middle, and lower zones. This ensures that the temperature regulation of each zone can be effectively implemented independently without mutual interference, significantly improving the effect of multi-zone temperature control. The gap reserved in the center of the heat insulation baffle 6 serves as a passage for crystal growth. The gap size is adapted to the growth and forming space of large-sized sapphire crystals, and will not obstruct or hinder the evaporation of melt in the furnace, the longitudinal growth of crystals, or the airflow circulation in the furnace. While ensuring the heat insulation zone effect, it fully meets the cavity flow and forming process requirements of KY method bubble growth crystals.

[0036] The limiting ribs 11 are arranged equidistantly along the inner wall of the upper heating element 3. The limiting ribs 11 extend from top to bottom into the interior of the lower heat insulation sleeve 9. Multiple sets of limiting ribs 11 are arranged in a uniform circumferential array, forming a vertical strip-type limiting structure. They penetrate the inner cavity space of the upper heating element 3, the middle heating element 4, and the lower heating element 5 from top to bottom, and extend to the inner side of the lower heat insulation sleeve 9 to form a full-length limiting and guiding structure. The limiting ribs 11 are mainly used to limit the crucibles assembled inside the furnace. The core built-in components, such as temperature measuring thermocouples and heat-conducting insulation components, are circumferentially limited and centered to restrict radial sway and angular deviation of various built-in components. This ensures that all core components for crystal growth are always located on the central axis of the furnace cavity, so that the center of the heating temperature field, the center of the melt, and the center of crystal growth in the furnace are highly aligned. This avoids problems such as uneven local heating, crystal stress concentration, and growth distortion caused by component eccentricity, and provides a stable structural alignment basis for the uniform forming of large-size sapphire single crystals.

[0037] The height adjustment component includes a furnace body base 12 located at the bottom of the furnace body 1. The furnace body base 12 is an integral, heavy-duty load-bearing base structure, fixedly installed at the bottom of the furnace body 1. It bears the entire weight of the furnace body shell and all internal heating, insulation, conductive, and limiting components, as well as the high-temperature working load. It can evenly distribute the overall pressure of the equipment, reduce the probability of local deformation during long-term static placement and operation, and ensure the stability of the overall installation foundation. A rotating bracket 13 is rotatably connected to the outer wall of the furnace body base 12. The rotating bracket 13 is a frame-type support structure that can rotate around the outer wall of the furnace body base 12, enabling synchronous angle adjustment of the entire upper furnace body structure. This facilitates factory assembly, on-site installation, and subsequent maintenance. The furnace body posture can be adjusted from multiple angles during maintenance, facilitating the observation, disassembly, and maintenance of the heating, insulation, and electrode structures on each layer inside the furnace, significantly improving the convenience of equipment operation and maintenance. Lifting hydraulic cylinders 14 are installed at the top of both sides of the rotating bracket 13. These cylinders are the core power actuators for adjusting the equipment height. Symmetrical arrangement ensures balanced lifting force, and precise vertical lifting is achieved through hydraulic extension and retraction. The overall vertical height of the furnace can be flexibly adjusted according to the different furnace temperature field height requirements of the sapphire crystal growth process and the docking height requirements of different supporting equipment, adapting to diverse production process scenarios. The output end of the lifting hydraulic cylinder 14 passes through the rotating bracket 13, ensuring that the power output end directly connects to the load-bearing structure, ensuring efficient force transmission. The rotation support 13 features stable and uniform delivery without any deviation or jamming. Support sleeves 15 are installed at the bottom of both sides. These support sleeves 15 are vertically fixed sleeve structures, serving as the external guide base for the bottom support telescopic structure. They constrain the movement trajectory of the internal telescopic structure, ensuring that the telescopic movement occurs only vertically, preventing lateral deviation or tilting of the support structure. Telescopic support legs 16 are slidably connected inside the support sleeves 15. These telescopic support legs 16 can freely slide and extend vertically within the support sleeves 15, allowing for minor adjustments to the support height. This allows for fine-tuning of the support height on each side based on the flatness error of the installation ground, correcting the overall levelness of the equipment, and ensuring that the furnace remains in a level and stable working state. The bottom of the telescopic support legs 16... The end is equipped with a fixed base 17, which is a large-size pressure-bearing base structure. This effectively increases the contact support area between the equipment and the ground, disperses the overall self-weight pressure of the equipment, reduces the local pressure load on the ground, and increases the friction of the contact surface. This effectively suppresses slippage and shaking caused by high-temperature operation and equipment adjustment, ensuring the overall stability of the equipment's working state. A rotating fixing part 18 is provided at the center of the front surface of the rotating bracket 13. The rotating fixing part 18 is a mechanical locking and positioning structure, which is used to lock and fix the rotating bracket 13 after it is adjusted to the preset working angle, restricting its free rotation and preventing the furnace body posture from shifting during equipment production operations, thus ensuring the stable state of the equipment after process debugging.

[0038] Multiple fixing slots are provided circumferentially along the edge of the rotating bracket 13, and the output end of the rotating fixing component 18 matches the fixing slots. Multiple sets of fixing slots are evenly spaced along the circumference of the rotating bracket 13, forming multiple angle positioning positions, corresponding to different rotation adjustment angles of the furnace body. The telescopic output end of the rotating fixing component 18 can be precisely embedded into the corresponding fixing slot, realizing multi-angle, high-precision mechanical locking positioning of the rotating bracket 13. The operator can flexibly switch the furnace body rotation angle and complete reliable fixing according to the actual needs of installation, debugging, maintenance, and production processes, adapting to the posture positioning requirements of the equipment under all working conditions, ensuring that it can maintain a stable locking state after each angle adjustment without loosening or deviation.

[0039] When using this invention: When the equipment is in operation, the overall posture and horizontal position of the machine are first adjusted and fixed by the bottom height adjustment component. After the equipment is installed in place, the overall working angle of the furnace body is adjusted by the rotatable characteristics of the rotating bracket. The angle is locked by the circumferential groove and the rotating fixing part. Then, the vertical extension and sliding of the telescopic legs is coordinated with the lifting hydraulic cylinders on both sides to adapt to the flatness of the installation ground and make fine adjustments and corrections to the overall height and horizontality of the furnace body. This keeps the furnace body cavity in a standard vertical and centered working posture, eliminating the internal temperature field deviation caused by equipment tilt and offset from the mechanical structure level, and providing a stable equipment foundation for subsequent uniform heating and precise temperature control.

[0040] After the equipment is fixed in position, the furnace is constructed with a complete set of heat insulation structures to create three independent sealed thermal environments: upper, middle, and lower zones. The three heating elements inside the furnace are arranged independently in an axial layered manner. Each heating element is matched with an independent heat insulation sleeve to achieve overall heat insulation on the outside, blocking heat loss to the furnace shell, reducing heat loss and preventing high-temperature aging of the furnace body. Adjacent heating elements are physically isolated and thermally blocked by heat insulation baffles, effectively isolating heat convection and heat conduction between the upper and lower areas, eliminating heat crosstalk between different temperature zones, and making the three heating areas independent in terms of physical structure and thermal field distribution, each forming an independent temperature control zone. This completely changes the traditional working mode of integrated heating elements with overall mixed temperature. At the same time, the limiting ribs on the inner wall of the furnace run through the entire thermal field cavity, keeping the crucible, temperature measuring components, and core built-in components centered and limiting them throughout the process, ensuring that the crystal growth axis coincides with the central axis of the thermal field, and avoiding local temperature differences and crystal growth defects caused by component eccentricity.

[0041] After the thermal zone structure is formed, the device enters a multi-zone independent DC heating operation. The equipment is connected to an independent DC power supply circuit through conductive electrode sleeves embedded inside each section of the heating element, allowing the upper, middle, and lower heating elements to be powered and heated independently. Compared with traditional AC heating methods, the DC power supply mode can avoid the skin effect, making the overall cross-section of the graphite heating element heat up evenly, and significantly improving heating efficiency and consistency. The three power supply circuits are independent of each other, and can output different voltages and powers according to the process requirements of different growth stages of large-size sapphire crystals, realizing independent control of the heating power of the three temperature zones. This solves the problems of traditional single-circuit overall heating, which cannot adjust the temperature in layers and has excessive axial temperature difference.

[0042] Based on independent heating in each zone, the device achieves dynamic and balanced temperature control across the entire furnace. During operation, the system collects temperature data from the upper, middle, and lower zones of the furnace in real time. Based on the preset standard temperature gradient parameters for the crystal growth process, it automatically compares the actual temperature differences between zones and adjusts the DC power output for each zone accordingly. It automatically reduces the heating power in areas with excessively high temperatures and automatically increases the heating power in areas with excessively low temperatures. Through a closed-loop control method of real-time feedback and dynamic fine-tuning, it continuously balances the axial and radial temperature distribution within the furnace, maintaining a uniform, symmetrical, and stable temperature field. This provides a high-precision, low-fluctuation, and locally overheat-free high-quality thermal environment for the growth of large-size sapphire KY method single crystals, effectively reducing defects such as crystal cracking, dislocations, and distortion, and improving the finished product quality and production stability of large-size sapphire single crystals.

Claims

1. A large-size sapphire KY process graphite hot zone multi-zone DC power supply adapter, comprising a furnace body (1), characterized in that, The furnace body (1) is provided with an upper heating element (3), a middle heating element (4) and a lower heating element (5) arranged from top to bottom. A heat insulation baffle (6) is provided at the gap between the upper heating element (3), the middle heating element (4) and the lower heating element (5). Multiple conductive electrode sleeves (10) are provided inside the upper heating element (3), the middle heating element (4) and the lower heating element (5). A limiting rib (11) is provided at the top of the inner wall of the upper heating element (3). The upper heating element (3), the middle heating element (4) and the lower heating element (5) are connected to the furnace body (1) through a heat insulation component. A height adjustment component is provided at the bottom of the furnace body (1).

2. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 1, characterized in that: The heat insulation assembly includes an upper heat insulation sleeve (7), a middle heat insulation sleeve (8), and a lower heat insulation sleeve (9) respectively disposed on the outer walls of the upper heating element (3), the middle heating element (4), and the lower heating element (5). The top of the outer walls of the upper heat insulation sleeve (7), the middle heat insulation sleeve (8), and the lower heat insulation sleeve (9) are all provided with a limiting ring plate, and the limiting ring plate is connected to the furnace body (1) through the furnace baffle ring (2).

3. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 1, characterized in that: The heat insulation baffle (6) is tightly fitted between the upper heating element (3), the middle heating element (4) and the lower heating element (5), and a gap is provided at the center of the heat insulation baffle (6).

4. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 1, characterized in that: The limiting ribs (11) are arranged equidistantly along the inner wall of the upper heating element (3), and the limiting ribs (11) extend from top to bottom into the interior of the lower heat insulation sleeve (9).

5. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 1, characterized in that: The height adjustment assembly includes a furnace body base (12) located at the bottom of the furnace body (1). A rotating bracket (13) is rotatably connected to the outer wall of the furnace body base (12). Lifting hydraulic cylinders (14) are provided at the top of both sides of the rotating bracket (13). The output end of the lifting hydraulic cylinder (14) passes through the rotating bracket (13). Leg sleeves (15) are provided at the bottom of both sides of the rotating bracket (13). Telescopic legs (16) are slidably connected inside the leg sleeves (15). A fixed seat (17) is provided at the bottom of the telescopic legs (16). A rotating fixing member (18) is provided at the center of the front surface of the rotating bracket (13).

6. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 5, characterized in that: The rotating bracket (13) has multiple fixing grooves along its circumferential direction at its edge, and the output end of the rotating fixing member (18) matches the fixing groove.

7. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 1, characterized in that: The upper heating element (3), middle heating element (4) and lower heating element (5) are each independently connected to a DC power supply circuit through their respective embedded conductive electrode sleeves (10). The three DC power supply circuits are electrically isolated and their power outputs do not interfere with each other. The DC current flows evenly through the entire cross section of the heating element to eliminate the skin effect of AC power supply.

8. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 7, characterized in that: The furnace body (1) is equipped with temperature acquisition units for the upper, middle and lower temperature zones respectively. Each temperature acquisition unit forms a signal closed loop with the control system of the corresponding DC power supply circuit. The DC output power of the corresponding upper heating element (3), middle heating element (4) and lower heating element (5) is dynamically adjusted according to the temperature field gradient requirements of each stage of crystal growth.

9. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 2, characterized in that: The upper insulation sleeve (7), the middle insulation sleeve (8), the lower insulation sleeve (9), and the insulation baffles (6) set between the layers together constitute a radial and axial bidirectional thermal barrier system. The insulation baffles (6) block the longitudinal heat conduction and furnace convection heat transfer between adjacent temperature zones, and each insulation sleeve blocks the radial heat radiation and heat conduction of the corresponding temperature zone, so that the three temperature zones form an independent closed temperature control unit.

10. The large-size sapphire KY process graphite thermal field multi-zone DC power supply adapter according to claim 4, characterized in that: Multiple circumferentially distributed limiting ribs (11) enclose a central limiting channel that runs through the entire cavity. After the crucible and temperature measuring element in the furnace are assembled along this channel, they maintain coaxiality with the upper section heating element (3), the middle section heating element (4), and the lower section heating element (5), so that the crystal growth center coincides with the central axis of the thermal field, ensuring uniform and symmetrical radial heating.

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