Graphite hard felt gradient control composite thermal field device for hemo method sapphire growth

Abstract

The application discloses a graphite hard felt gradient regulation and control composite thermal field device for HEM sapphire growth, which comprises a first main body structure, a second main body structure and an adjusting structure, the second main body structure is fixedly arranged on the first main body structure, the second main body structure and the first main body structure can be docked and separated, a pair of first hydraulic cylinder bodies are symmetrically arranged between the first main body structure and the second main body structure, and the adjusting structure is movably arranged on the second main body structure, and the application relates to the technical field of sapphire growth heating equipment, and the dovetail groove tenon joint is used for splicing, the splicing structure is stable and is not prone to dislocation, the double-layer hard felt is cross-laid, the heat flow is blocked from leaking due to gap dislocation, the gap is filled with a soft felt sealing strip, high-temperature deformation is adapted, and continuous sealing is realized; a water-cooling heat-insulating shell is designed, the furnace body protection and the production environment optimization are considered, the hydraulic split type cavity structure is good in airtightness, the mode is adjustable, and the annular electric heater is precisely controllable and longitudinal temperature gradient.

Description

Technical Field

[0001] This invention relates to the technical field of heating equipment for HEM sapphire growth, specifically a graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth. Background Technology

[0002] Sapphire single crystals are widely used in semiconductor substrates, infrared optical windows, laser components and other fields due to their excellent optical, mechanical and high temperature resistance properties. The HEM heat exchange method is the mainstream process for preparing large-size, low-defect sapphire crystals. The crystal growth quality is highly dependent on the uniformity of the temperature gradient and the heat preservation and sealing of the furnace thermal field. As the core heat preservation and insulation material of the thermal field, the assembly and sealing structure of graphite hard felt directly determines the temperature field stability during the crystal growth process. Currently, HEM sapphire growth thermal fields generally use a single layer of graphite rigid felt as the insulation layer. To facilitate disassembly and maintenance, the rigid felt is often divided into multiple fan-shaped separate structures, with the joints sealed simply by bonding them together. When in use, the poor sealing performance of the joints of the split hard felt makes it easy for heat radiation and hot air to leak out from the joints. This not only increases energy consumption significantly, but also exacerbates the high-temperature wear of consumables such as graphite felt and heaters, shortening the service life of the equipment. Heat leakage from the joints directly causes violent fluctuations in the temperature field inside the furnace, making it difficult to control the longitudinal and radial temperature gradients stably. In addition, the height of the traditional top heating component in the hot zone is fixed, making it impossible to dynamically and precisely correct the temperature gradient. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a graphite hard felt gradient control composite thermal field device for HEM sapphire growth, which addresses the shortcomings of the prior art, and prevents heat leakage and temperature field instability at the splicing gaps of graphite hard felt, improves the heat preservation effect, and ensures the stability of the temperature gradient.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth, comprising a first main structure, a second main structure, and an adjustment structure. The second main structure is fixedly mounted on the first main structure, and the second main structure and the first main structure are capable of docking and separating. The second main structure is identical to the first main structure, but arranged in opposite directions. A pair of first hydraulic cylinder bodies are symmetrically arranged between the first main structure and the second main structure. The adjustment structure is movably mounted on the second main structure. A bearing unit is fixedly passed through the first main structure. The first main structure is used to form the bottom of the hot zone, the second main structure is used to form the top of the hot zone, the adjustment structure is used to adjust the heating height, and the support unit is used to support the placement of the crucible.

[0005] Preferably, the first main structure includes a base, several pillars, a sealing seat, a first insulation unit, a second insulation unit, a pair of heat-insulating shells, a first baffle, and several first bolts; the base is circular, the several pillars are equidistantly arranged on the upper wall of the base along the circumference, the sealing seat is a convex disc structure, and the diameter of one end of the sealing seat is larger than that of the other end. The lower wall of one end of the sealing seat is fixedly disposed on the other end of the several pillars, and a groove is formed on the circumference of the side wall of one end of the sealing seat. The first insulation unit is detachably fitted onto the other end of the sealing seat, and the second insulation unit has the same structure as the first insulation unit, and the second insulation unit is detachably fitted onto the outside of the first insulation unit. The bottom of each pair of heat-insulating shells is symmetrically fitted into the slots at one end of the sealing seat, and the heat-insulating shells are connected by several first bolts. The pair of heat-insulating shells are fitted onto the outside of the first insulation unit and the second insulation unit. The top opening of each pair of heat-insulating shells fits into the first insulation unit. A water cavity is provided in the middle of each pair of heat-insulating shells, and a pair of first connection ports are provided on the side wall of one of the heat-insulating shells. The first baffle is fixedly installed in the middle of one of the heat-insulating shells and isolates one of the water cavities into two parts. The first baffle is located between the pair of first connection ports. The pair of heat-insulating shells can completely fasten the first insulation unit and the second insulation unit.

[0006] Preferably, the first insulation unit includes two pairs of first insulation hard felts, several mating felt rods, several soft felt sealing strips, and several second bolts; both pairs of first insulation hard felts are fan-shaped with the same diameter, and the two ends of the two pairs of first insulation hard felts can be spliced ​​together to form an annular cylinder, and the mating ends of the first insulation hard felts are symmetrically provided with dovetail grooves, and the front side of each dovetail groove is symmetrically provided with a sealing groove. After the two pairs of first insulation hard felts are mated in sequence, they are fixedly fitted on the outside of the other end of the sealing seat. Several mating felt rods are respectively movably fitted in the corresponding dovetail grooves, several soft felt sealing strips are respectively movably fitted in the corresponding sealing grooves, and several second bolts are respectively countersunk and screwed into the two ends of the first insulation hard felts, and the second bolts can be tightened against the mating felt rods.

[0007] Preferably, the base of the second main structure has a rotating opening in the middle, the sealing seat of the second main structure has a bearing embedded in the middle, and a lifting groove is provided through one side of the bearing.

[0008] Preferably, the bottom ends of a pair of first hydraulic cylinder bodies are symmetrically arranged on the base of the first main structure and located on both sides of the heat insulation shell (16), and the telescopic ends of the pair of first hydraulic cylinder bodies are respectively connected to the base of the second main structure.

[0009] Preferably, the adjustment structure includes a drive seat, a lifting arm, rollers, a spring, a motor, a pair of pulleys, a transmission belt, a boom, an electric push rod, and an annular electric heater. The drive seat is a T-shaped frustum structure, with one end fixedly inserted into the middle of the bearing. The other end of the drive seat has symmetrically arranged arc-shaped claws on its upper wall. One end of the lifting arm movably passes through the lifting groove of the sealing seat in the second main structure, and a lifting opening is provided in the middle of one end of the lifting arm. The other end of the lifting arm corresponds to the drive seat. The rollers are movably disposed on the other end of the lifting arm and are in contact with the drive seat. The rollers can be moved up and down by the rotation of the drive seat. One end of the spring is fixedly disposed on the upper wall of the sealing seat in the second main structure. The other end of the spring is connected to the lower wall of the middle part of the lifting arm. The motor is fixedly installed on the upper wall of the sealing seat in the second main structure and located outside the drive seat. A pair of pulleys are respectively fixedly installed on the motor drive end and one end of the drive seat. The transmission belt is movably fitted between the pair of pulleys. The boom is L-shaped. One end of the boom moves through the lifting port at one end of the lifting seat and is located inside the second main structure. One end of the electric push rod is fixedly installed in the middle of the lifting arm, and the telescopic end of the electric push rod is connected to the other end of the boom. The telescopic drive of the electric push rod can drive the boom to rise and fall inside the lifting arm. The annular electric heater is fixedly installed on one end of the boom and is located inside the second main structure.

[0010] Preferably, the supporting unit includes an air supply pipe, a second partition, a supporting platform, and a third partition; the air supply pipe is fixedly inserted through the middle of the sealing seat of the first main structure, and a pair of second adapters are provided at the bottom of the air supply pipe; the second partition is fixedly embedded in the middle of the air supply pipe, and the second partition is located between the second adapters; the supporting platform is a T-shaped hollow frustum structure; the supporting platform is fixedly fitted on the top of the air supply pipe, and the supporting platform is located in the first insulation unit; the third partition is fixedly embedded in the middle of the supporting platform, and the third partition can isolate the supporting platform into two relatively connected cooling chambers; the third partition and the second partition are mated and fitted together.

[0011] Preferably, the motor start-up can drive the drive seat to rotate, and through the top claw, it can reciprocate to drive the lifting arm and the boom to move up and down.

[0012] Preferably, both the first pair of connection ports and the second pair of connection ports are used for corresponding medium input and output, so as to promote the medium to flow in and out of the heat insulation shell and the air supply pipe.

[0013] Compared with existing technologies, this solution uses a simple mechanical structure, employing a dovetail groove to join four pieces of hard felt together to form a cylindrical shape. A double-layer hard felt sleeve ensures the joint edges interlock, enhancing insulation and preventing heat loss from gaps. Simultaneously, soft felt sealing strips further conceal the joints, better accommodating thermal expansion and contraction. An external heat-insulating shell, through water circulation, absorbs heat, preventing excessive external heat radiation from affecting the surrounding environment. Two identical first and second main structures are connected and separated by a pair of hydraulic cylinders, creating a sealed, temperature-controlled environment. During use, the height of the annular electric heater can be adjusted to a certain extent according to the crystal growth height, and it can reciprocate upward and downward movement to maintain the internal temperature gradient at higher levels. In summary, the beneficial effects of this invention are: 1. The cylinder is formed by interlocking four fan-shaped graphite hard felts with dovetail grooves. Compared with simple planar bonding, the dovetail grooves have lateral limiting ability. During the high-temperature thermal expansion and contraction cycle, the hard felts will not slip or misalign with each other, avoiding the continuous increase of splicing gaps. Structurally, this reduces heat leakage channels and stabilizes the basic temperature field inside the furnace.

[0014] 2. The inner and outer layers of hard felt are spliced ​​independently, and the seams of the two layers are staggered and not connected. Heat radiation and hot air cannot be lost directly to the outside through a straight gap, forming an interlaced heat insulation barrier, which greatly reduces heat loss through gaps and significantly improves the heat retention effect inside the furnace. The temperature will not continue to drop or fluctuate frequently due to heat leakage.

[0015] 3. A soft felt sealing strip is added inside the splicing groove to flexibly fill the gap. On the one hand, it directly seals the tiny gaps to prevent heat loss; on the other hand, the soft felt is elastic and can adapt to the dimensional changes of graphite hard felt at high temperature expansion and low temperature contraction. It will not cause the gap to expand due to thermal expansion, and maintain the sealing and heat insulation effect for a long time, solving the defect of traditional hard joint sealing failure after high temperature.

[0016] 4. An externally snap-fit ​​heat-insulating shell is installed and circulated with cooling water. On the one hand, it absorbs the residual heat radiated outward by the hard felt, further blocking the high temperature inside the furnace from being conducted outward, reducing overall heat loss and helping to stabilize the internal thermal field; on the other hand, it significantly reduces the surface temperature of the outer wall of the equipment, preventing high-temperature heat radiation from baking surrounding parts and operators, improving the workshop working environment, and protecting the outer metal structure of the furnace body, reducing high-temperature aging losses, and extending the service life of the whole machine.

[0017] 5. The upper and lower symmetrical main structures are combined with the opening and closing driven by the hydraulic cylinders on both sides. During production, the hydraulic cylinders drive the upper and lower cavities to precisely align and close, forming a complete and sealed heat-insulating furnace chamber, reducing side heat overflow.

[0018] 6. Adjustable ring-shaped electric heater, precisely controllable longitudinal temperature gradient: The heater supports reciprocating lifting and moving: the height of the upper heat source can be changed periodically over a wide range to adapt to the different requirements of the longitudinal temperature field for different growth stages of sapphire crystal introduction, diameter expansion and constant diameter. The heating height can be independently finely adjusted: it can precisely compensate for temperature changes inside the furnace and stabilize the temperature in the upper part of the furnace. With dual adjustment modes and a bottom helium cooling support unit, the overall temperature gradient inside the furnace can be flexibly controlled to avoid local overheating or undercooling of the temperature field, reduce defects such as crystal thermal stress, dislocations, and cracks, and improve the quality of sapphire single crystal products. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the assembly structure of the present invention; Figure 2 This is a schematic diagram of the first main structure of the present invention broken down; Figure 3 This is a schematic diagram of the split structure of the second main body of the present invention; Figure 4 This is a schematic diagram of the disassembled structure of the adjustment structure of the present invention; Figure 5 This is a schematic diagram of the assembly structure of the adjustment structure of the present invention; Figure 6 This is a schematic diagram showing the assembly of the second main structure and the adjustment structure of the present invention; Figure 7 for Figure 2 A magnified schematic diagram of the structure at point A in the diagram; Figure 8 for Figure 2 A magnified schematic diagram of the structure at point B in the diagram; Figure 9 for Figure 4 A magnified schematic diagram of the structure at point C.

[0020] In the diagram: 1. First main structure; 11. Base; 12. Support column; 13. Sealing seat; 14. First insulation unit; 141. First insulation rigid felt; 142. Connecting felt rod; 143. Soft felt sealing strip; 144. Second bolt; 15. Second insulation unit; 16. Heat insulation shell; 17. First baffle; 18. First bolt; 2. Second main structure; 3. Adjustment structure; 31. Drive seat; 32. Lifting arm; 33. Roller; 34. Spring 35. Motor, 36. Pulley, 37. Transmission belt, 38. Boom, 39. Electric push rod, 30. Annular electric heater, 4. Bearing unit, 41. Air supply pipe, 42. Second partition, 43. Bearing platform, 44. Third partition, 5. Hydraulic cylinder body, 61. Slot, 62. First connection port, 63. Water chamber, 71. Dovetail groove, 72. Sealing groove, 73. Rotary port, 74. Bearing, 75. Lifting groove, 8. Lifting port, 9. Top claw. Detailed Implementation

[0021] The following will refer to the appendices in the embodiments of the present invention. Figures 1-9 For further details: This invention provides a technical solution: a graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth, comprising a first main structure 1, a second main structure 2, and an adjustment structure 3. The second main structure 2 is fixedly mounted on the first main structure 1, and the second main structure 2 and the first main structure 1 can be connected and separated. The second main structure 2 is identical to the first main structure 1, but arranged in opposite directions. A pair of first hydraulic cylinder bodies 5 are symmetrically arranged between the first main structure 1 and the second main structure 2. The adjustment structure 3 is movably mounted on the second main structure 2. A bearing unit 4 is fixedly passed through the first main structure 1. The first main structure 1 forms the bottom of the thermal field, the second main structure 2 forms the top of the thermal field, the adjustment structure 3 is used to adjust the heating height, and the bearing unit 4 is used to support the placement of the crucible.

[0022] As a preferred embodiment, the first main structure 1 further includes a base 11, several pillars 12, a sealing seat 13, a first insulation unit 14, a second insulation unit 15, a pair of heat-insulating shells 16, a first baffle 17, and several first bolts 18. The base 11 is circular, and the several pillars 12 are equidistantly arranged on the upper wall of the base 11 along the circumference. The sealing seat 13 has a convex disc structure, and the diameter of one end of the sealing seat 13 is larger than that of the other end. The lower wall of one end of the sealing seat 13 is fixedly mounted on the other end of the several pillars 12, and the sealing seat 13 is tightly sealed. A slot 61 is provided on the circumference of one side wall of the sealing seat 13. The first insulation unit 14 is detachably fitted onto the other end of the sealing seat 13. The second insulation unit 15 has the same structure as the first insulation unit 14 and is detachably fitted onto the outside of the first insulation unit 14. A pair of heat insulation shells 16 are symmetrically fitted into the slot 61 at one end of the sealing seat 13 at their bottoms, and the heat insulation shells 16 are connected by several first bolts 18. The pair of heat insulation shells 16 are fitted onto the first insulation unit 14 and the second insulation unit 15. On the outside, the top openings of a pair of heat-insulating shells 16 fit into the first heat-insulating unit 14. Each pair of heat-insulating shells 16 has a water cavity 63 in its middle, and one of the heat-insulating shells 16 has a pair of first connection ports 62 on its side wall. A first baffle 17 is fixedly installed inside the middle of one of the heat-insulating shells 16, dividing one of the water cavities 63 into two parts. The first baffle 17 is located between the pair of first connection ports 62. The pair of heat-insulating shells 16 can completely fasten the first heat-insulating unit 14 and the second heat-insulating unit 15. The circular base 11 supports the convex sealing seat 13 through the evenly distributed support columns 12 around the circumference; the inner first insulation unit 14 and the outer second insulation unit 15 are detachably fitted onto the upper end of the sealing seat 13 in layers, and the double-layer insulation felt forms a cylindrical heat insulation layer; the two halves of the heat insulation shell 16 are inserted into the side wall slots 61 of the sealing seat 13 and locked by the first bolt 18 to enclose and wrap the double-layer insulation felt; the water cavity 63 inside the shell is separated by a baffle, and the cooling water enters and exits from a pair of interfaces on the side wall, and completes the circulation heat exchange in the water cavity 63, forming an overall enclosed and sealed heat insulation structure.

[0023] More specifically, both the first insulation unit 14 and the second insulation unit 15 can be disassembled and installed separately, so there is no need to replace the whole unit when the hard felt is partially damaged, reducing material costs and maintenance time; after the two halves of the heat insulation shell 16 are locked together, they completely cover the double layer of insulation felt, blocking the heat dissipation channels on the outside of the insulation layer. Together with the inner double layer of hard felt, they doubly block the leakage of heat radiation from the furnace and stabilize the furnace temperature; the baffle separates the water cavity 63, and the cooling water flows in an orderly manner, fully carrying away the heat conducted outward by the insulation felt; this not only reduces the heat loss of the furnace body and stabilizes the internal temperature field, but also significantly reduces the temperature of the outer wall of the equipment, protecting the external structure and improving the operating environment.

[0024] As a preferred embodiment, the first insulation unit 14 further includes two pairs of first insulating hard felts 141, several mating felt rods 142, several soft felt sealing strips 143, and several second bolts 144. Both pairs of first insulating hard felts 141 are fan-shaped with the same diameter. The two ends of the two pairs of first insulating hard felts 141 can be spliced ​​together to form an annular cylinder. The mating ends of the first insulating hard felts 141 are symmetrically provided with dovetail grooves 71, and the front sides of the dovetail grooves 71 are symmetrically provided with sealing grooves 72. After the two pairs of first insulating hard felts 141 are sequentially mated, they are fixedly fitted onto the outer side of the other end of the sealing seat 13. The several mating felt rods 142 are respectively movably fitted into the corresponding dovetail grooves 71, and the several soft felt... The sealing strips 143 are respectively movably fitted into the corresponding sealing grooves 72. Several second bolts 144 are respectively countersunk and screwed into both ends of the first thermal insulation felt 141, and the second bolts 144 can be tightened against the connecting felt rods 142. Through the dovetail grooves 71 at the ends of multiple fan-shaped hard felts, they interlock with the connecting felt rods 142 to form a complete cylinder. The connecting felt rods 142 are embedded in the dovetail grooves 71 to achieve splicing and positioning. Soft felt sealing strips 143 are filled into the sealing grooves 72 to fill the gaps. The countersunk second bolts 144 tighten the connecting felt rods 142 to lock all hard felt splicing positions. The buffer groove on the outer wall of the hard felt reserves space for thermal deformation. The entire unit is fitted onto the sealing seat 13 to form an inner thermal insulation cylinder.

[0025] More specifically, compared to flat bonding, the dovetail groove 71 forms a limiting structure, preventing the hard felt from slipping or misaligning under high-temperature thermal expansion and contraction, thus avoiding the widening of splicing gaps and reducing heat leakage channels; the sealing strip fills the splicing gaps and, at the same time, relies on its own elasticity to offset the dimensional changes caused by the thermal expansion and contraction of the hard felt, continuously sealing the gaps under long-term high-temperature conditions and stabilizing the insulation effect; the countersunk second bolt 144 presses the mating felt rod 142 to ensure that the splicing surfaces of each hard felt are tightly fitted and stably connected; the fan-shaped first thermal insulation hard felt 141 can be disassembled individually, and local damage only requires replacement of a single felt body, without the need for overall replacement, reducing consumable and maintenance costs.

[0026] As a preferred option, the base 11 in the second main structure 2 has a rotating opening 73 in the middle, and the sealing seat 13 in the second main structure 2 has a bearing 74 embedded in the middle, with a lifting groove 75 extending through one side of the bearing 74.

[0027] As a preferred option, furthermore, the bottom ends of a pair of first hydraulic cylinder bodies 5 are symmetrically arranged on the base 11 of the first main structure 1 and located on both sides of the heat insulation shell (16), and the telescopic ends of the pair of first hydraulic cylinder bodies 5 are respectively connected to the base 11 of the second main structure 2.

[0028] As a preferred embodiment, the adjustment structure 3 further includes a drive base 31, a lifting arm 32, rollers 33, springs 34, a motor 35, a pair of pulleys 36, a transmission belt 37, a boom 38, an electric push rod 39, and an annular electric heater 30. The drive base 31 has a T-shaped frustum structure, and one end of the drive base 31 is fixedly inserted into the middle of the bearing 74. The other end of the drive base 31 has symmetrically arranged arc-shaped top claws 9 on its upper wall. One end of the lifting arm 32 movably passes through the lifting groove 75 of the sealing seat 13 in the second main structure 2, and a lifting port 8 is provided in the middle of one end of the lifting arm 32. The other end of the lifting arm 32 corresponds to the drive seat 31. A roller 33 is movably mounted on the other end of the lifting arm 32 and is in contact with the drive seat 31. The roller 33 can be moved up and down by the rotation of the drive seat 31. One end of the spring 34 is fixedly mounted on the upper wall of the sealing seat 13 in the second main structure 2, and the other end of the spring 34 is connected to the lower wall of the middle part of the lifting arm 32. The motor 35 is fixedly mounted on the upper wall of the sealing seat 13 in the second main structure 2 and is located outside the drive seat 31. A pair of pulleys 36 are respectively fixedly mounted on the drive end of the motor 35 and the drive seat 31. At one end, a transmission belt 37 is movably fitted between a pair of pulleys 36. The boom 38 is L-shaped, with one end of the boom 38 movably passing through the lifting port 8 at one end of the lifting seat, and one end of the boom 38 is located inside the second main structure 2. One end of the electric push rod 39 is fixedly installed in the middle of the lifting arm 32, and the telescopic end of the electric push rod 39 is connected to the other end of the boom 38. The telescopic drive of the electric push rod 39 can drive the boom 38 to rise and fall within the lifting arm 32. An annular electric heater 30 is fixedly installed on one end of the boom 38, and the annular electric heater 30 is located inside the second main structure 2; the motor 35 starts. The lifting arm 32 is driven to rotate via pulley 36 and transmission belt 37. The arc-shaped top claw 9 of the driving arm 31 continuously pushes the bottom roller 33 of the lifting arm 32, and with the spring 34 resetting, the lifting arm 32 is driven to achieve periodic reciprocating lifting and lowering. The lifting arm 32 is equipped with an L-shaped boom 38. The electric push rod 39 can independently drive the boom 38 to slide up and down slightly within the lifting port 8. The annular electric heater 30 is installed at the lower end of the boom 38. It completes large-range reciprocating coarse adjustment with the lifting arm 32 and small-amplitude precise fine adjustment with the boom 38, thereby changing the height of the heater in the furnace.

[0029] More specifically, the heater reciprocates and rises through a rotating cam mechanism, adapting to the overall temperature field requirements at different stages of crystal growth; the electric push rod 39 performs high-precision compensation, which can correct the longitudinal temperature gradient in real time, resulting in higher temperature control accuracy; the spring 34 continuously pulls down the lifting arm 32, ensuring that the roller 33 always fits against the top claw 9 of the drive seat 31, eliminating transmission gaps, ensuring smooth lifting and lowering movements, and preventing failure during long-term high-temperature operation; the position of the upper heat source can be dynamically changed to stabilize the longitudinal temperature field of the furnace, reduce internal thermal stress in the crystal, and reduce defects such as dislocations and cracks, adapting to the entire HEM sapphire growth process.

[0030] As a preferred embodiment, the supporting unit 4 further includes an air supply pipe 41, a second partition 42, a supporting platform 43, and a third partition 44. The air supply pipe 41 is fixedly inserted through the middle of the sealing seat 13 of the first main structure 1, and a pair of second adapters are provided at the bottom of the air supply pipe 41. The second partition 42 is fixedly embedded in the middle of the air supply pipe 41, and the second partition 42 is located between the second adapters. The supporting platform 43 is a T-shaped hollow frustum structure, and the supporting platform 43 is fixedly fitted onto the top of the air supply pipe 41, and the supporting platform 43 is located inside the first insulation unit 14. The third partition 44 is fixedly embedded in the middle of the support platform 43, and the third partition 44 can isolate the support platform 43 into two relatively connected cooling chambers. The third partition 44 is mated and fits with the second partition 42. The cooling medium is introduced from one of the second transition ports at the bottom of the gas supply pipe 41, and then diverted through the internal second partition 42 into the support platform 43. The third partition 44 in the support platform 43 divides the cavity into two interconnected cooling chambers. After the medium exchanges heat fully with the bottom of the crucible, it flows back along another channel and is discharged from the second transition port, completing the circulating cooling.

[0031] More specifically, the cooling airflow can be evenly filled in the cavity of the support platform 43 by the precise distribution of the medium through the second partition 42, and the bottom of the crucible can be synchronously heated without local uneven cooling. The temperature gradient between the upper and lower parts required for the HEM process can be stably established. The gas supply pipe 41 and the upper and lower partitions of the support platform 43 are connected and fit together, the flow channel is sealed and there is no leakage, the cooling medium loss is small and the heat exchange efficiency is stable. The support platform 43 is arranged inside the double-layer insulation unit, and the cooling effect is concentrated on the seed crystal area of ​​the crucible. It will not interfere with the overall insulation environment inside the furnace, and takes into account both insulation and bottom heat exchange requirements.

[0032] As a preferred option, the motor 35 can be started to drive the drive seat 31 to rotate, and through the top claw 9, it can reciprocate to drive the lifting arm 32 and the boom 38 to move up and down.

[0033] As a preferred embodiment, both the first connection port 62 and the second connection port 76 are used for the corresponding medium input and output, so as to cause the medium to flow in and out of the heat insulation shell 16 and the air supply pipe 41.

[0034] Working principle: First, the entire device relies on the hydraulic cylinder body 5 to open and close the upper and lower cavities. The bottom is supported by the base 11 and the evenly arranged pillars 12. The sealing seat 13 is supported by the base 11. The side wall of the sealing seat 13 has a slot 61 for mounting the heat insulation shell 16. The upper part of the sealing seat 13 is fitted with two layers of heat insulation structure: the first heat insulation unit 14 and the second heat insulation unit 15. The first insulation unit 14 is formed by splicing together multiple fan-shaped first insulation hard felts 141. Dovetail grooves 71 and sealing grooves 72 are opened at the joint ends of the hard felts. The joint felt rods 142 are inserted into the dovetail grooves 71 to achieve splicing and positioning. The sealing grooves 72 are filled with soft felt sealing strips 143 to seal the splicing gaps. Then, the joint felt rods 142 are tightened by countersunk second bolts 144, so that all the hard felts are tightly attached to form a complete cylindrical inner insulation body. The structure of the second insulation unit 15 is completely the same as that of the first insulation unit 14. It is fitted on the outside of the first insulation unit 14. The seams of the two layers of insulation felt are interlaced to block the straight heat leakage channel. After a pair of heat insulation shells 16 are inserted into the slots 61 of the sealing seat 13, they are locked together by several first bolts 18 to completely wrap the two insulation units. A water cavity 63 is set inside the heat insulation shell 16. A first baffle 17 is fixed in one of the water cavities 63 to divide the water cavity 63 into independent inlet and outlet channels. Cooling water is introduced into the first connection port 62 on the side wall of the heat insulation shell 16. The cooling water circulates in the divided water cavity 63 to continuously absorb the heat radiated outward by the insulation layer. The sealing seat 13 is centrally mounted with the support unit 4. The bottom of the gas supply pipe 41 of the support unit 4 is provided with a second connection port 76. The second partition 42 is fixed inside the gas supply pipe 41. A T-shaped, hollow support platform 43 is fitted at the top of the gas supply pipe 41. A third partition 44 is embedded inside the support platform 43. The third partition 44 is precisely aligned with the second partition 42, dividing the inner cavity of the support platform 43 into two interconnected cooling chambers. The cooling medium enters the gas supply pipe 41 from the second connection port 76 on one side, and after being diverted by the partition, it evenly fills the inner cavity of the support platform 43, fully exchanging heat with the bottom of the crucible placed on the support platform 43. Then, it flows out from the second connection port 76 on the other side along another flow path, continuously providing bottom cooling for crystal growth. The upper part of the device is provided with a second main structure 2 arranged symmetrically to the first main structure 1. The two ends of the hydraulic cylinder body 5 are respectively connected to the base 11 and the base 11 of the second main structure 2. The second main structure 2 is raised and lowered as a whole by hydraulic extension and retraction, so as to complete the closing and separation of the hot zone cavity. The base 11 of the second main structure 2 has a rotary port 73, and the middle of its sealing seat 13 is fitted with a bearing 74. The side of the bearing 74 is reserved with a lifting groove 75 to provide movement space for the top temperature regulating component. The second main structure 2 has a complete set of adjustment structures 3 mounted on the sealing seat 13. The motor 35 is fixed above the sealing seat 13. The output end of the motor 35 and the drive seat 31 are respectively equipped with pulleys 36. The transmission belt 37 is sleeved between the two sets of pulleys 36. The operation of the motor 35 can drive the T-shaped drive seat 31 to rotate synchronously. The upper end of the drive seat 31 has an arc-shaped top claw 9. The lifting arm 32 is arranged through the lifting groove 75 of the sealing seat 13. The lower end of the lifting arm 32 is equipped with a roller 33 and is in contact with the surface of the drive seat 31. The upper wall of the sealing seat 13 is connected to a spring 34. The top of the spring 34 pulls the lifting arm 32 so that the roller 33 is always in close contact with the top claw of the drive seat 31. 9. When the drive seat 31 rotates, the top claw 9 repeatedly lifts the roller 33, and with the tension of the spring 34, the lifting arm 32 is periodically raised and lowered. A lifting port 8 is opened in the middle of the lifting arm 32, and the L-shaped boom 38 extends into the furnace through the lifting port 8. An electric push rod 39 is installed on the lifting arm 32. The telescopic end of the electric push rod 39 is connected to the boom 38, which can drive the boom 38 to slide up and down in the lifting port 8 independently. A ring electric heater 30 is fixed at the bottom of the boom 38. The heater completes a large range of coarse reciprocating adjustment with the lifting arm 32 and a fine adjustment of height with the boom 38, dynamically changing the position of the heat source in the upper part of the furnace, thereby controlling the longitudinal temperature gradient in the furnace. During overall operation, the hydraulic cylinder body 5 presses down the second main structure 2 and closes it with the bottom first main structure 1 to form a sealed and insulated furnace chamber. The double-layer graphite hard felt combined with the soft felt sealing strip 143 eliminates heat leakage from the splicing gaps. The water-cooled circuit of the heat-insulating shell 16 isolates the high temperature of the outer wall. The bearing unit 4 continuously introduces cooling medium to achieve heat exchange at the bottom of the crucible. The top adjustment structure 3 adjusts the height of the annular electric heater 30 in two modes. The bottom cooling and the upper heat source work together to regulate the stable temperature gradient of the furnace chamber, meeting the requirements of the entire process of HEM sapphire single crystal growth. When the equipment is under maintenance or the crucible is being removed or placed, the hydraulic cylinder body 5 lifts the second main structure 2 to open the hot zone cavity. At the same time, each heat-insulating unit, heat-insulating shell 16, and temperature-regulating component are modular and detachable structures, which facilitates the individual replacement and maintenance of internal parts.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Other modifications or functional substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A graphite hard felt gradient-controlled composite thermal field device for sapphire growth using the HEM method, characterized in that, It includes a first main structure (1), a second main structure (2) and an adjustment structure (3). The second main structure (2) is fixedly installed on the first main structure (1), and the second main structure (2) and the first main structure (1) can be connected and separated. The second main structure (2) is the same as the first main structure (1) and is arranged in opposite directions. A pair of first hydraulic cylinder bodies (5) are symmetrically arranged between the first main structure (1) and the second main structure (2). The adjustment structure (3) is movably installed on the second main structure (2). The first main structure (1) is fixedly penetrated by a bearing unit (4). The first main structure (1) is used to form the bottom of the hot zone, the second main structure (2) is used to form the top of the hot zone, the adjustment structure (3) is used to adjust the heating height, and the bearing unit (4) is used to support the placement of the crucible.

2. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 1, characterized in that, The first main structure (1) includes a base (11), several pillars (12), a sealing seat (13), a first heat insulation unit (14), a second heat insulation unit (15), a pair of heat insulation shells (16), a first baffle (17), and several first bolts (18). The base (11) is circular, and several pillars (12) are equidistantly arranged on the upper wall of the base (11) along the circumference. The sealing seat (13) is a convex disc structure, and the diameter of one end of the sealing seat (13) is larger than that of the other end. The lower wall of one end of the sealing seat (13) is fixedly arranged on the other end of several pillars (12), and a slot (61) is opened on the circumference of the side wall of one end of the sealing seat (13). The first heat insulation unit (14) is detachably fitted onto the other end of the sealing seat (13). The second heat insulation unit (15) has the same structure as the first heat insulation unit (14). The second heat insulation unit (15) is detachably fitted onto the outside of the first heat insulation unit (14). The bottoms of a pair of heat insulation shells (16) are symmetrically fitted into the slots (61) at one end of the sealing seat (13), and the heat insulation shells are... (16) By connecting several of the first bolts (18), a pair of heat insulation shells (16) are fitted onto the outside of the first heat insulation unit (14) and the second heat insulation unit (15). The top opening of the pair of heat insulation shells (16) fits into the first heat insulation unit (14). A water cavity (63) is provided in the middle of each pair of heat insulation shells (16), and a pair of first connection ports (62) are provided on the side wall of one of the heat insulation shells (16). The first baffle (17) is fixedly installed in the middle of one of the heat insulation shells (16) and separates one of the water cavities (63) into two parts. The first baffle (17) is located between the pair of first connection ports (62). The pair of heat insulation shells (16) can completely fasten the first heat insulation unit (14) and the second heat insulation unit (15).

3. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 2, characterized in that, The first insulation unit (14) includes two pairs of first insulation hard felt (141), several mating felt rods (142), several soft felt sealing strips (143), and several second bolts (144). Both pairs of the first thermal insulation felt (141) are fan-shaped with the same diameter. The two ends of the two pairs of the first thermal insulation felt (141) can be spliced ​​together to form an annular cylinder. The joint ends of the first thermal insulation felt (141) are symmetrically provided with dovetail grooves (71). The front side of the dovetail grooves (71) is symmetrically provided with sealing grooves (72). After the two pairs of the first thermal insulation felt (141) are joined together in sequence, they are fixedly fitted on the outside of the other end of the sealing seat (13). Several of the joint felt rods (142) are respectively movably fitted in the corresponding dovetail grooves (71). Several of the soft felt sealing strips (143) are respectively movably fitted in the corresponding sealing grooves (72). Several of the second bolts (144) are respectively countersunk and screwed into the two ends of the first thermal insulation felt (141). The second bolts (144) can be tightened against the joint felt rods (142).

4. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 3, characterized in that, The base (11) of the second main structure (2) has a rotating port (73) in the middle, and the sealing seat (13) of the second main structure (2) has a bearing (74) embedded in the middle, and a lifting groove (75) is provided through one side of the bearing (74).

5. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 4, characterized in that, A pair of first hydraulic cylinder bodies (5) are symmetrically arranged on the base (11) of the first main structure (1) at their bottom ends and located on both sides of the heat insulation shell (16). The telescopic ends of the pair of first hydraulic cylinder bodies (5) are respectively connected to the base (11) of the second main structure (2).

6. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 5, characterized in that, The adjustment structure (3) includes a drive seat (31), a lifting arm (32), a roller (33), a spring (34), a motor (35), a pair of pulleys (36), a transmission belt (37), a boom (38), an electric push rod (39), and an annular electric heater (30). The drive seat (31) is a T-shaped frustum structure, and one end of the drive seat (31) is fixedly inserted into the middle of the bearing (74). The upper wall of the other end of the drive seat (31) is symmetrically provided with arc-shaped top claws (9). One end of the lifting arm (32) movably passes through the lifting groove (75) of the sealing seat (13) in the second main structure (2), and a lifting port (8) is provided in the middle of one end of the lifting arm (32). The other end of the lifting arm (32) corresponds to the drive seat (31). The roller (33) is movably disposed on the other end of the lifting arm (32), and the roller (33) is in contact with the drive seat (31). The roller (33) can be driven to move up and down by the rotation of the drive seat (31). One end of the spring (34) is fixedly disposed on the upper wall of the sealing seat (13) in the second main structure (2), and the other end of the spring (34) is connected to the lower wall of the middle part of the lifting arm (32). The motor (35) is fixedly disposed on the upper wall of the sealing seat (13) in the second main structure (2). The sealing seat (13) is placed on the upper wall of the sealing seat (13) in the second main structure (2) and is located outside the drive seat (31). A pair of pulleys (36) are fixedly installed on the drive end of the motor (35) and one end of the drive seat (31). The transmission belt (37) is movably fitted between the pair of pulleys (36). The boom (38) is L-shaped. One end of the boom (38) moves through the lifting port (8) at one end of the lifting seat and one end of the boom (38) is located inside the second main structure (2). One end of the electric push rod (39) is fixedly installed in the middle of the lifting arm (32) and the telescopic end of the electric push rod (39) is connected to the other end of the boom (38). The telescopic drive of the electric push rod (39) can drive the boom (38) to rise and fall inside the lifting arm (32). The annular electric heater (30) is fixedly installed on one end of the boom (38) and the annular electric heater (30) is located inside the second main structure (2).

7. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 6, characterized in that, The supporting unit (4) includes an air supply pipe (41), a second partition (42), a supporting platform (43), and a third partition (44). The air supply pipe (41) is fixedly inserted through the middle of the sealing seat (13) of the first main structure (1), and a pair of second adapters are provided at the bottom of the air supply pipe (41). The second partition (42) is fixedly embedded in the middle of the air supply pipe (41), and the second partition (42) is located between the second adapters. The support platform (43) is a T-shaped cavity frustum structure. The support platform (43) is fixedly fitted on the top of the air supply pipe (41), and the support platform (43) is located in the first insulation unit (14). The third partition (44) is fixedly embedded in the middle of the support platform (43), and the third partition (44) can isolate the support platform (43) into two relatively connected cooling chambers. The third partition (44) and the second partition (42) are mated together.

8. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 7, characterized in that, The motor (35) can drive the drive seat (31) to rotate when started, and drive the lifting arm (32) and the boom (38) to move up and down through the top claw (9).

9. The graphite hard felt gradient-controlled composite thermal field device for HEM sapphire growth according to claim 8, characterized in that, A pair of first connection ports (62) and a pair of second connection ports (76) are used for corresponding medium input and output, causing the medium to flow in and out of the heat insulation shell (16) and the air supply pipe (41).

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