Production equipment and method for long-service-life compression-resistant graphite crucible

Abstract

The invention discloses long-service-life compression-resistant graphite crucible production equipment which comprises a rack, a mixing and kneading pot is arranged on the rack, two overturning supports are arranged on the two sides of the mixing and kneading pot, a discharging hopper is arranged below the mixing and kneading pot, a spiral conveyor is arranged at the bottom of the discharging hopper, a weighing hopper is arranged at the discharging end of the spiral conveyor, and a gate valve is arranged at the bottom of the weighing hopper. A die moving mechanism is arranged below the weighing hopper, a die is arranged on the die moving mechanism, a pressure forming machine is arranged above the die moving mechanism, and a discharging plate is arranged between the die moving mechanism and the pressure forming machine. The invention further discloses a production method of the long-service-life compression-resistant graphite crucible, the graphite crucible is produced through the steps of raw material preparation, isostatic pressing forming, stepped roasting, vacuum dipping treatment, gradient graphitization, precision machining and the like in sequence, the efficiency is high, the raw material utilization rate is high, and the produced crucible is long in service life, high in compression resistance and high in yield. And the labor intensity is reduced in the production process.

Description

Technical Field

[0001] The present invention relates to the technical field of graphite crucible manufacturing, and in particular to equipment and a method for producing a long-life, pressure-resistant graphite crucible. Background Art

[0002] Graphite crucibles offer excellent thermal conductivity and high-temperature resistance. They exhibit a low coefficient of thermal expansion during high-temperature use and a certain degree of strain resistance to rapid heating and cooling. They are highly resistant to corrosion in acidic and alkaline solutions and possess excellent chemical stability. They are widely used in the smelting of alloy tool steels and the melting of nonferrous metals and their alloys in industries such as metallurgy, casting, machinery, and chemicals, achieving excellent technical and economic benefits.

[0003] Currently, graphite crucible raw materials face challenges in mixing uniformity and discharging. During the mixing process of graphite powder and additives, the additives have poor fluidity and easily remain on the inner wall of the container, requiring manual cleaning. Furthermore, discharging efficiency after mixing is low, impacting production continuity. Furthermore, traditional pressure forming equipment (such as molding and isostatic pressing) relies on manual parameter adjustment, which can easily lead to uneven crucible density due to operational errors, thereby reducing compressive performance and service life. Furthermore, existing graphite crucible production equipment has poor interoperability. Most production lines lack an integrated design, with each process operating independently. This results in low material flow efficiency, difficulty in ensuring crucible density uniformity, and local defects that can lead to reduced compressive performance. Summary of the Invention

[0004] The present invention provides a long-life, pressure-resistant graphite crucible production device, which solves the problems of low material pouring efficiency after mixing in traditional graphite crucible production technology, affecting production continuity, independent operation of each process equipment, resulting in low material flow efficiency, difficulty in ensuring crucible density uniformity, and local defects leading to reduced pressure resistance.

[0005] The present invention provides a long-life pressure-resistant graphite crucible production device, comprising a frame, a kneading pot is provided on the frame, two flip brackets are provided on both sides of the kneading pot, a lower hopper is provided below the kneading pot, a screw conveyor is provided at the bottom of the lower hopper, a weighing hopper is provided at the discharge end of the screw conveyor, a gate valve is provided at the bottom of the weighing hopper, a mold moving mechanism is provided below the weighing hopper, a mold is provided on the mold moving mechanism, a pressure forming machine is provided above the mold moving mechanism, and a discharge plate is provided between the mold moving mechanism and the pressure forming machine.

[0006] Furthermore, the flip bracket includes a flip shaft, a flip wheel, a limiting wheel, a first motor, and a mounting plate, wherein the two flip shafts are horizontally arranged on both sides of the kneading pot, one end of each flip shaft is fixedly connected to the kneading pot, and the other end is coaxially fixedly connected to the flip wheel disc, a vertical mounting plate is provided on the frame on one side of the flip wheel disc, a plurality of limiting wheels are provided around each flip wheel disc, the central axis of each limiting wheel is rotatably connected to the shaft seat provided on the mounting plate, a first motor is provided on the frame at the lower end of the mounting plate, the output shaft of the first motor is coaxially fixedly connected to the central axis of one of the limiting wheels through a coupling, an annular groove is provided on the rolling surface of the flip wheel disc along the circumferential direction, and each limiting wheel partially extends into the annular groove and is rollingly connected to the flip wheel disc.

[0007] Furthermore, a cleaning mechanism is provided on the weighing hopper, and the cleaning mechanism includes a positioning gear, a driving gear, a motor mounting seat, a second motor, and a scraper plate. The driving gear is coaxially arranged on the top of the weighing hopper, the scraper plate is arranged in the weighing hopper and fixedly connected to the driving gear, and the driving gear is provided with multiple positioning shafts along the circumferential direction, and a positioning gear is rotatably provided on each of the positioning shafts, and each of the positioning gears is respectively engaged with the driving gear for transmission cooperation, a motor mounting seat is provided on the top of the weighing hopper, and a second motor is provided on the motor mounting seat, and the output shaft of the second motor is coaxially and fixedly connected to one of the positioning shafts.

[0008] Furthermore, the mold moving mechanism includes a guide rail, a guide block, a first hydraulic cylinder, a second hydraulic cylinder, and a support plate. The two guide rails are horizontally arranged on the frame, a guide block is arranged between the two guide rails, a mold fixedly connected to the guide block is arranged on the guide block, a first hydraulic cylinder for driving the guide block to move along the two guide rails is arranged on the frame at one end of the two guide rails, a guide hole is arranged at the bottom of the guide block, a second hydraulic cylinder is arranged at the bottom of the guide block, and a support plate is arranged at the telescopic end of the second hydraulic cylinder.

[0009] Furthermore, the pressure forming machine includes two vertical plates arranged vertically on the frame, a mounting top plate is arranged at the upper ends of the two vertical plates, a spiral shaft is arranged between the two vertical plates, the upper end of the spiral shaft passes through the mounting top plate and is rotatably connected to a bearing seat arranged on the mounting top plate, a driving mechanism is arranged on the mounting top plate, a screw sleeve is arranged at the lower end of the spiral shaft, a guide block is arranged at the bottom of the screw sleeve, four tracks cooperating with the guide block are arranged around the guide block, a guide rod is arranged at the bottom of the guide block, a pressure shaft is arranged at the lower end of the guide rod, a movable pressure ring is sleeved on the side wall of the pressure shaft, an annular boss is arranged on the side wall of the pressure shaft above the movable pressure ring, a compression spring is arranged between the annular boss and the movable pressure ring, the upper end of the compression spring is elastically fixedly connected to the lower end face of the annular boss, and the lower end is elastically fixedly connected to the upper end face of the movable pressure ring.

[0010] Furthermore, a discharge hole is provided on the discharge plate, a third hydraulic cylinder is provided on the discharge plate, an arc-shaped push plate is provided at the telescopic end of the third hydraulic cylinder, and a conveyor is provided on one side of the discharge plate.

[0011] Furthermore, a fourth hydraulic cylinder is vertically arranged on the unloading plate, and the telescopic end of the fourth hydraulic cylinder passes through the unloading hole and is fixedly connected to the positioning plate. An annular oil spray pipe is arranged at the bottom of the positioning plate, and multiple nozzles are arranged on the side walls around the annular oil spray pipe. The annular oil spray pipe is connected to the oil tank and the oil pump through the oil supply pipe.

[0012] The present invention also discloses a method for producing a long-life, pressure-resistant graphite crucible, comprising the following steps: S1. Raw material preparation: The particle size composition satisfies D50 = 15-25μm, D90 ≤ 50μm flake graphite and medium temperature asphalt according to the mass ratio of 75-85:15-25 were added to the kneading pot and mixed, and stirred at 180-220 ℃ for 1-2 hours to form a homogeneous mixture; S2 isostatic pressing: The mixture is poured into the lower hopper and transported to the weighing hopper by a screw conveyor for weighing. After reaching the weighing requirement, the gate valve is opened by the controller, the mixture is added to the mold, and then the mold is sent to the bottom of the pressure molding machine by the mold moving mechanism. The pressure molding machine applies an isostatic pressure of 150-250MPa and holds the pressure for 10-30 minutes to obtain a graphite crucible green body; S3 stepped calcination: heating at a rate of 10-15 ℃ / h to 800-1000 ℃, holding for 20-40 hours, then heating at 5-8 ℃ / h to 1200-1300 ℃ for secondary calcination, a total calcination time of 80-120 hours; S4 vacuum impregnation treatment: The calcined body is placed in a vacuum impregnation tank, liquid phenolic resin is injected under a vacuum degree of 0.08-0.1MPa, and pressurized to 1.5-2.5MPa for 4-8 hours; S5. Gradient graphitization: Under argon protection, heat up to 2400-2800°C at 20-50°C / h and keep at this temperature for 10-20 hours; S6. Precision machining: Use CNC machine tools for turning of internal and external surfaces, and control the surface roughness at Ra ≤ 3.2μm.

[0013] It can be seen from the above technical solutions that the present invention provides a long-life, pressure-resistant graphite crucible production device. Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention mixes graphite crucible raw materials in a kneading pot, assists in turning and unloading by two turning brackets, introduces the mixed materials into a screw conveyor through a lower hopper, conveys the mixed materials to a weighing hopper through the screw conveyor, accurately weighs them in the weighing hopper and pours them into a mold, and transfers the mold to the bottom of a pressure molding machine through a mold moving mechanism to complete pressure molding. The process of raw material preparation, isostatic pressing, step-by-step roasting, vacuum impregnation treatment, gradient graphitization, and precision machining are sequentially carried out to produce graphite crucibles with high efficiency and high raw material utilization, saving labor intensity throughout the entire process. Through equipment linkage design, manual handling and parameter adjustment are reduced, reducing production costs by 30%.

[0014] 2. The present invention combines an anti-sticking mixing device with an intelligent pressing device, which increases production efficiency by 40% compared with traditional processes.

[0015] 3. The present invention ensures the uniformity of crucible density (error ≤ 2%) by precisely controlling the molding parameters, increases the compressive strength by more than 20%, and extends the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for implementation. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a schematic diagram of the overall structure of a long-life, pressure-resistant graphite crucible production device and method proposed by the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of a flip bracket for producing a long-life, pressure-resistant graphite crucible proposed by the present invention; Figure 3 This is a schematic diagram of the weighing hopper structure of the long-life, pressure-resistant graphite crucible production equipment and method proposed in the present invention; Figure 4 This is a schematic diagram of the installation position structure of the mold moving mechanism of the long-life, pressure-resistant graphite crucible production equipment and method proposed by the present invention; Figure 5 This is a schematic diagram of the installation position structure of the annular oil injection pipe of the long-life, pressure-resistant graphite crucible production equipment and method proposed by the present invention; Figure 6 This is a schematic structural diagram of a pressure forming machine for producing a long-life, pressure-resistant graphite crucible according to the present invention; Figure 7 The present invention is attached Figure 1 Schematic diagram of the partially enlarged structure at position Ⅰ; Figure 8 The present invention is attached Figure 1Schematic diagram of the partially enlarged structure at position II; Figure 9 This is a schematic diagram of the three-dimensional structure of the mold moving mechanism of the long-life, pressure-resistant graphite crucible production equipment and method proposed by the present invention; Figure 10 The present invention provides a cross-sectional schematic diagram of the mold installation structure of a long-life, pressure-resistant graphite crucible production device and method.

[0018] In the picture: 1- rack; 2- Mixing pot; 3- flip bracket; 31- flip shaft; 32- flip wheel; 33- limit wheel; 34- first motor; 35- mounting plate; 331- center shaft; 36- coupling; 37- electromagnetic clutch; 4- lower hopper; 5-Screw conveyor; 6-weighing hopper; 60-gate valve; 61-clearing mechanism; 62-positioning gear; 63-driving gear; 64-motor mounting seat; 65-second motor; 66-scraper; 631-positioning shaft; 7-mold moving mechanism; 71-guide rail; 72-guide block; 73-first hydraulic cylinder; 74-second hydraulic cylinder; 75-support plate; 712-guide hole; 8-pressure forming machine; 81-vertical plate; 82-mounting top plate; 83-screw shaft; 84-threaded sleeve; 85-guide block; 86-track; 87-guide rod; 88-pressure shaft; 89-driving mechanism; 881-movable pressure ring; 882-annular boss; 883-compression spring; 9-unloading plate; 90-third hydraulic cylinder; 91-unloading hole; 92-fourth hydraulic cylinder; 93-positioning plate; 94-annular oil spray pipe; 95-spray nozzle; 901-arc push plate; 902-conveyor; 100-mold; 101-demolding hole; 200-graphite crucible. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0020] Example 1: See also Figure 1-10A long-life pressure-resistant graphite crucible production equipment includes a frame 1, a kneading pot 2 is arranged on the frame 1, the kneading pot 2 is an existing commercially available product, two flip brackets 3 are arranged on both sides of the kneading pot 2, a lower hopper 4 is arranged below the kneading pot 2, a screw conveyor 5 is arranged at the bottom of the lower hopper 4, a weighing hopper 6 is arranged at the discharge end of the screw conveyor 5, a gate valve 60 is arranged at the bottom of the weighing hopper 6, a mold moving mechanism 7 is arranged below the weighing hopper 6, a mold 100 is arranged on the mold moving mechanism 7, a pressure molding machine 8 is arranged above the mold moving mechanism 7, and a discharge plate 9 is arranged between the mold moving mechanism 7 and the pressure molding machine 8. The graphite crucible is stirred and mixed uniformly by the kneading pot 2, and the graphite crucible is stirred and mixed uniformly by the two kneading pots. The turning bracket 3 pours the mixed raw materials in the kneading pot 2 into the lower hopper 4 and guides it into the screw conveyor 5. The raw materials are conveyed to the weighing hopper 6 by the screw conveyor 5. After being weighed by the weighing hopper 6, the raw materials are quantitatively added to the mold 100. The mold moving mechanism 7 transfers the mold 100 containing the raw materials to the bottom of the pressure molding machine 8. The pressure molding machine 8 applies pressure to produce a graphite crucible green body. The mold moving mechanism 7 can quickly move the graphite crucible 200 green body out of the mold 100. The production efficiency of the graphite crucible is high, the utilization rate of the raw materials is high, and the labor intensity of the whole process is saved. Through the equipment linkage design, manual handling and parameter adjustment are reduced, thereby reducing production costs.

[0021] Specifically, see Figure 2The turning bracket 3 in this embodiment includes a turning shaft 31, a turning wheel disc 32, a limiting wheel 33, a first motor 34, and a mounting plate 35. The rolling surface of the limiting wheel 33 is knurled. The knurled pattern increases the friction between the limiting wheel 33 and the turning wheel disc 32, so that the limiting wheel 33 drives the turning wheel disc 32 to rotate synchronously. The two turning shafts 31 are horizontally arranged on both sides of the kneading pot 2. One end of each turning shaft 31 is fixedly connected to the outer wall of the kneading pot 2, and the other end is coaxially fixedly connected to the turning wheel disc 32. The two turning wheel discs 32 are vertically arranged on both sides of the kneading pot 2. A vertical mounting plate 35 is provided on the frame 1 on one side of the turning wheel disc 32. Four limiting wheels 33 are provided around each turning wheel disc 32. The central axis 331 of each limiting wheel 33 is rotatably connected to the bearing in the shaft seat provided on the mounting plate 35. A first motor 34 is mounted on the frame 1 at the lower end of the mounting plate 35. The output shaft of the first motor 34 is coaxially fixedly connected to the central axis of one of the limiting wheels 33 via a coupling 36. An electromagnetic clutch 37 connected to the mounting plate 35 is mounted on the central axis of the limiting wheel 33. The electromagnetic clutch 37 controls the braking of the first motor 34, allowing the kneading pot 2 to rotate to the discharge angle. An annular groove is formed along the circumference of the rolling surface of the tilting wheel 32. Each limiting wheel 33 partially extends into the annular groove and is in rolling connection with the tilting wheel 32. The first motor 34 drives the coupling 36 to rotate the limiting wheels 33, which in turn rotates the tilting wheel 32. During rotation of the tilting wheel 32, the open end of the kneading pot 2 faces downward, which increases the discharge speed and allows the mixed raw materials to be quickly removed from the kneading pot 2.

[0022] In this embodiment, see Figure 3A cleaning mechanism 61 is provided on the weighing hopper 6. The bottom of the weighing hopper 6 is suspended on the frame 1 through a plurality of weighing sensors to weigh the weight of the material in the weighing hopper 6. The weighing sensors are evenly distributed on the frame 1 around the bottom of the weighing hopper 6. The cleaning mechanism 61 includes a positioning gear 62, a driving gear 63, a motor mounting seat 64, a second motor 65, and a scraper plate 66. The driving gear 63 is coaxially arranged on the top of the weighing hopper 6. The scraper plate 66 is installed in contact with the conical inner wall of the weighing hopper 6. The upper end of the scraper plate 66 is fixedly connected to the driving gear 63. A plurality of vertical positioning shafts 631 are provided around the driving gear 63 along the circumferential direction. Each positioning shaft 631 is provided along the circumferential direction. The lower end of the positioning shaft 631 is fixedly connected to the top of the weighing hopper 6, and a positioning gear 62 is rotatably set on each positioning shaft. Each positioning gear 62 is respectively engaged with the driving gear 63 for transmission. A motor mounting seat 64 is fixedly set on the top of the weighing hopper 6, and a second motor 65 is fixedly set on the motor mounting seat 64. The output shaft of the second motor 65 is coaxially fixedly connected to one of the positioning shafts. The second motor 65 drives one of the positioning gears 62 to rotate, driving the driving gear 63 to rotate. The rotation of the driving gear 63 drives the scraper plate 66 to rotate along the conical inner wall of the weighing hopper 6 to scrape the material, so as to prevent the material from staying in the weighing hopper 6 for a long time and sticking to the inner wall.

[0023] In this embodiment, see Figure 4 、 5, 9, 10, the mold moving mechanism 7 includes a guide rail 71, a guide block 72, a first hydraulic cylinder 73, a second hydraulic cylinder 74, and a support plate 75. The two guide rails 71 are horizontally arranged on the frame 1, and a guide block 72 is slidingly arranged between the two guide rails 71. Linear bosses are arranged on both end surfaces of the guide block 72, and guide grooves are arranged on the inner side surfaces of the guide rails 71. The guide block 72 extends into the two guide grooves arranged on the inner sides of the two guide rails 71 through the linear bosses on both sides to guide the sliding fit. A mold 100 fixedly connected to it is arranged on the guide block 72. The mold 100 is cylindrical, and its inner cavity is also cylindrical. A cylindrical demoulding hole 101 connected to the inner cavity of the mold 100 is arranged at the bottom of the mold 100. A first hydraulic cylinder 73 for driving the guide block 72 to move along the two guide rails 71 is arranged on the frame 1 at one end of the two guide rails 71. A guide hole 712 is arranged at the bottom of the guide block 72. 12 is vertically connected to the demoulding hole 101, a hydraulic cylinder mounting seat is provided at the bottom of the guide block 72, and a second hydraulic cylinder 74 is fixedly provided on the hydraulic cylinder mounting seat. A horizontal support plate 75 is provided at the telescopic end of the second hydraulic cylinder 74. Before the mold 100 is loaded, the support plate 75 is driven by the second hydraulic cylinder 74 to pass through the guide hole 712 and enter the demoulding hole 101 to block the demoulding hole 101. After the loading is completed, the first hydraulic cylinder 73 drives the guide block 72, the second hydraulic cylinder 74 and the support plate 75 to move as a whole to the bottom of the pressure forming machine 8, and the pressure forming machine 8 is used to press the graphite crucible raw material in the mold cavity of the mold 100 into shape. Then, the second hydraulic cylinder 74 drives the support plate 75 to move upward, and the graphite crucible green body formed in the mold 100 is lifted up and moved out of the mold 100 until the bottom of the mold 100 is flush with the surface of the unloading plate 9. The demoulding speed of the graphite crucible green body is fast, the demoulding efficiency is high, and time and labor are saved.

[0024] In this embodiment, see Figure 6The pressure forming machine 8 includes two vertical plates 81 vertically arranged on the frame 1, and a mounting top plate 82 is arranged on the upper ends of the two vertical plates 81. A screw shaft 83 is arranged between the two vertical plates 81. The upper end of the screw shaft 83 passes through the mounting top plate 82 and is rotatably connected to the bearing seat arranged on the mounting top plate 82. A driving mechanism 89 is arranged on the mounting top plate 82. A screw sleeve 84 is arranged at the lower end of the screw shaft 83. A guide block 85 is arranged at the bottom of the screw sleeve 84. Four tracks 86 that cooperate with the guide block 85 are arranged around the guide block 85. A guide rod 87 is arranged at the bottom of the guide block 85. A pressure shaft 88 is arranged at the lower end of the guide rod 87. The pressure shaft A movable pressure ring 881 is sleeved on the side wall of 88, an annular boss 882 is provided on the side wall of the pressure shaft 88 above the movable pressure ring 881, a compression spring 883 is provided between the annular boss 882 and the movable pressure ring 881, the upper end of the compression spring 883 is elastically fixedly connected to the lower end surface of the annular boss 882, and the lower end is elastically fixedly connected to the upper end surface of the movable pressure ring 881. During the downward pressing process of the pressure shaft 88, the compression spring 883 drives the movable pressure ring 881 to pass through the discharge hole 91 provided on the discharge plate 9, and closes the upper end of the mold 100 to prevent the raw material from being removed, thereby increasing the utilization rate of the raw material and making the mold 100 0, so that the overall strength of the graphite crucible is uniform, wherein the driving mechanism includes a third motor, a third motor, a first pulley, a second pulley, a third pulley, a fourth pulley, a first transmission belt, and a second transmission belt. The third motor and the third motor are respectively arranged at the bottom of both ends of the mounting top plate. The first pulley is arranged on the output shaft of the third motor and is connected to the second pulley arranged on the spiral shaft through the first transmission belt for transmission. The third pulley is arranged on the output shaft of the third motor and is connected to the fourth pulley arranged on the spiral shaft for transmission through the second transmission belt. The output shaft of the third motor is driven by the third motor to drive the first The pulley rotates, and the first pulley rotates through the first transmission belt to drive the second pulley to rotate. The second pulley rotates to drive the spiral shaft to rotate clockwise. The spiral shaft rotates clockwise and cooperates with the spiral pair of the screw sleeve to move downward quickly. The third motor drives its output shaft to rotate the third pulley. The third pulley rotates through the second transmission belt to drive the fourth pulley to rotate. The fourth pulley rotates to drive the spiral shaft counterclockwise. The spiral shaft rotates counterclockwise and cooperates with the spiral pair of the screw sleeve to move upward quickly, which can realize rapid reversal of the spiral shaft, so that the pressure shaft 88 can impact the graphite in the mold with a greater impact force to quickly form it.

[0025] In this embodiment, see Figure 4 、 5A discharge hole 91 is provided on the discharge plate 9, and a third hydraulic cylinder 90 is fixedly provided on the discharge plate 9 on one side of the discharge hole 9. An arc-shaped push plate 901 is fixedly provided at the telescopic end of the third hydraulic cylinder 90. The arc surface of the arc-shaped push plate 901 is adapted to the side wall of the graphite crucible green body. A horizontal conveyor 902 is provided on one side of the discharge plate 9. The graphite crucible on the support plate 75 is horizontally pushed to the conveyor 902 through the arc-shaped push plate 901 by the third hydraulic cylinder 90 for the next process, thereby saving manual labor intensity in the transfer process.

[0026] In this embodiment, see Figure 4 、 5 A fourth hydraulic cylinder 92 is vertically arranged on the unloading plate 9. The telescopic end of the fourth hydraulic cylinder 92 passes through the unloading hole 91 and is fixedly connected to the positioning plate 93. An annular oil spray pipe 94 is arranged at the bottom of the positioning plate 93. A plurality of nozzles 95 are arranged on the side walls of the annular oil spray pipe 94. The annular oil spray pipe 94 is connected to the oil tank and the oil pump through an oil supply pipe. When the empty mold moves back to the bottom of the annular oil spray pipe 94, the annular oil spray pipe 94 is driven by the fourth hydraulic cylinder 92 to extend into the inner cavity of the mold 100, and the inner wall of the mold 100 is sprayed with oil through the plurality of nozzles 95 to increase the demoulding efficiency.

[0027] In this embodiment, a controller is also installed on the frame 1, and a display is provided on the controller. The weighing sensor is connected to the display to display the weight value sensed by the weighing sensor. In this embodiment, the long-life, pressure-resistant graphite crucible production equipment further includes a controller and a host computer. The controller is electrically connected to the host computer. The controller is electrically connected to the load cell, kneading pot 2, first motor 34, electromagnetic clutch 37, screw conveyor 5, gate valve 60, second motor 65, first hydraulic cylinder 73, second hydraulic cylinder 74, pressure forming machine 8, third hydraulic cylinder 90, fourth hydraulic cylinder 92, and conveyor 902. The long-life, pressure-resistant graphite crucible production equipment is controlled by the controller and the host computer. The control parameters of the controller are set by the host computer, the controller receives signal feedback from the load cell, and the operation of the various connected devices is controlled by buttons on the DCS controller. Alternatively, the operation of the various connected devices can be controlled by programming using a PLC controller, thereby further improving the operating efficiency of the equipment.

[0028] A method for producing a long-life, pressure-resistant graphite crucible of the present invention comprises the following steps: S1. Raw material preparation: The particle size composition satisfies D50 = 15-25μm, D90 ≤ 50μm flake graphite and medium temperature asphalt according to the mass ratio of 75-85:15-25 were added to the kneading pot 2 and mixed, and stirred at 180-220 ℃ for 1-2 hours to form a homogeneous mixture; S2 isostatic pressing: The mixture is poured into the lower hopper 4 and transported to the weighing hopper 6 by the screw conveyor 5 for weighing. After reaching the weighing requirement, the gate valve 60 is opened by the controller, and the mixture is added to the mold 100. The mold 100 is then sent to the bottom of the pressure molding machine 8 by the mold moving mechanism 7. The pressure molding machine 8 is applied at an isostatic pressure of 150-250MPa and the pressure is maintained for 10-30 minutes to obtain a graphite crucible green body; S3 stepped calcination: heating at a rate of 10-15 ℃ / h to 800-1000 ℃, holding for 20-40 hours, then heating at 5-8 ℃ / h to 1200-1300 ℃ for secondary calcination, a total calcination time of 80-120 hours; S4 vacuum impregnation treatment: The calcined body is placed in a vacuum impregnation tank, liquid phenolic resin is injected under a vacuum degree of 0.08-0.1MPa, and pressurized to 1.5-2.5MPa for 4-8 hours; S5. Gradient graphitization: Under argon protection, heat up to 2400-2800°C at 20-50°C / h and keep at this temperature for 10-20 hours; S6. Precision machining: Use CNC machine tools for turning of internal and external surfaces, and control the surface roughness at Ra ≤ 3.2μm.

[0029] The fixed carbon content of the flake graphite in step (1) is ≥99.5%, and the softening point of the medium-temperature asphalt is 85-95°C.

[0030] The secondary roasting stage in step (3) adopts a carbon-burying protection process, and the filler is composed of metallurgical coke and quartz sand in a volume ratio of 1:2-3.

[0031] The impregnation treatment in step (4) is repeated 2-3 times, and an intermediate roasting treatment at 600-800°C is required after each impregnation.

[0032] In step (5), the graphitization process adopts a zone temperature control technology, and the temperature at the bottom of the crucible is 50-100°C higher than that at the mouth.

[0033] The method further includes step (7) surface modification treatment: depositing a 10-50 μm silicon carbide coating on the graphite surface by chemical vapor deposition.

[0034] The final product meets the requirements of bulk density ≥1.80g / cm³, apparent porosity ≤15%, and room temperature compressive strength ≥45MPa.

[0035] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope of the invention being indicated by the claims.

[0036] It should be understood that the present invention is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The above-described embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention.

Claims

1. A long-life, compression-resistant graphite crucible production equipment, characterized by: The invention comprises a frame (1), a kneading pot (2) is provided on the frame (1), two flip brackets (3) are provided on both sides of the kneading pot (2), a lower hopper (4) is provided below the kneading pot (2), a screw conveyor (5) is provided at the bottom of the lower hopper (4), a weighing hopper (6) is provided at the discharge end of the screw conveyor (5), a gate valve (60) is provided at the bottom of the weighing hopper (6), a mold moving mechanism (7) is provided below the weighing hopper (6), a mold (100) is provided on the mold moving mechanism (7), a pressure forming machine (8) is provided above the mold moving mechanism (7), and a discharge plate (9) is provided between the mold moving mechanism (7) and the pressure forming machine (8).

2. The long-life compression-resistant graphite crucible production equipment according to claim 1, characterized in that: The flip bracket (3) comprises a flip shaft (31), a flip wheel (32), a limiting wheel (33), a first motor (34), and a mounting plate (35). The two flip shafts (31) are horizontally arranged on both sides of the kneading pot (2). One end of each flip shaft (31) is fixedly connected to the kneading pot (2), and the other end is coaxially fixedly connected to the flip wheel (32). A vertical mounting plate (35) is arranged on the frame (1) on one side of the flip wheel (32). A plurality of limiting wheels ( 33), the central axis (331) of each of the limiting wheels (33) is rotatably connected to the shaft seat provided on the mounting plate (35), a first motor (34) is provided on the frame (1) at the lower end of the mounting plate (35), the output shaft of the first motor (34) is coaxially fixedly connected to the central axis of one of the limiting wheels (33) through a coupling, an annular groove is provided on the rolling surface of the flip wheel (32) along the circumferential direction, and each of the limiting wheels (33) partially extends into the annular groove and is rollingly connected to the flip wheel (32).

3. The long-life compression-resistant graphite crucible production equipment according to claim 1, characterized in that: A material cleaning mechanism (61) is provided on the weighing hopper (6), and the material cleaning mechanism (61) includes a positioning gear (62), a driving gear (63), a motor mounting seat (64), a second motor (65), and a scraper plate (66). The driving gear (63) is coaxially provided on the top of the weighing hopper (6), and the scraper plate (66) is provided in the weighing hopper (6) and fixedly connected to the driving gear (63). The driving gear (63) is provided with a plurality of positioning shafts (631) along the circumferential direction, and a positioning gear (62) is rotatably provided on each of the positioning shafts. Each of the positioning gears (62) is respectively meshed with the driving gear (63) for transmission cooperation. A motor mounting seat (64) is provided on the top of the weighing hopper (6), and a second motor (65) is provided on the motor mounting seat (64). The output shaft of the second motor (65) is coaxially fixedly connected to one of the positioning shafts.

4. The long-life compression-resistant graphite crucible production equipment according to claim 1, characterized in that: The mold moving mechanism (7) comprises a guide rail (71), a guide block (72), a first hydraulic cylinder (73), a second hydraulic cylinder (74), and a support plate (75). The two guide rails (71) are horizontally arranged on the frame (1). A guide block (72) is arranged between the two guide rails (71). A mold (100) fixedly connected to the guide block (72) is arranged on the frame (1). A first hydraulic cylinder (73) for driving the guide block (72) to move along the two guide rails (71) is arranged on the frame (1) at one end of the two guide rails (71). A guide hole (712) is arranged at the bottom of the guide block (72). A second hydraulic cylinder (74) is arranged at the bottom of the guide block (72). A support plate (75) is arranged at the telescopic end of the second hydraulic cylinder (74).

5. The long-life compression-resistant graphite crucible production equipment according to claim 1, characterized in that: The pressure forming machine (8) comprises two vertical plates (81) arranged on a frame (1), a mounting top plate (82) being arranged on the upper ends of the two vertical plates (81), a spiral shaft (83) being arranged between the two vertical plates (81), the upper end of the spiral shaft (83) passing through the mounting top plate (82) and being rotatably connected to a bearing seat arranged on the mounting top plate (82), a driving mechanism (89) being arranged on the mounting top plate (82), a screw sleeve (84) being arranged on the lower end of the spiral shaft (83), a guide block (85) being arranged at the bottom of the screw sleeve (84), and four guide blocks (85) being arranged around the guide block (85). A track (86) is matched with the guide block (85), a guide rod (87) is provided at the bottom of the guide block (85), a pressure shaft (88) is provided at the lower end of the guide rod (87), a movable pressure ring (881) is sleeved on the side wall of the pressure shaft (88), an annular boss (882) is provided on the side wall of the pressure shaft (88) above the movable pressure ring (881), a compression spring (883) is provided between the annular boss (882) and the movable pressure ring (881), an upper end of the compression spring (883) is elastically fixedly connected to the lower end surface of the annular boss (882), and a lower end is elastically fixedly connected to the upper end surface of the movable pressure ring (881).

6. The long-life, pressure-resistant graphite crucible production equipment according to claim 1, characterized in that: A discharge hole (91) is provided on the discharge plate (9), a third hydraulic cylinder (90) is provided on the discharge plate (9), an arc-shaped push plate (901) is provided at the telescopic end of the third hydraulic cylinder (90), and a conveyor (902) is provided on one side of the discharge plate (9).

7. The long-life, pressure-resistant graphite crucible production equipment according to claim 6, characterized in that: A fourth hydraulic cylinder (92) is vertically arranged on the discharge plate (9), and the telescopic end of the fourth hydraulic cylinder (92) passes through the discharge hole (91) and is fixedly connected to the positioning plate (93). An annular oil spray pipe (94) is arranged at the bottom of the positioning plate (93), and a plurality of nozzles (95) are arranged on the side walls around the annular oil spray pipe (94). The annular oil spray pipe (94) is connected to the oil tank and the oil pump through an oil supply pipe.

8. A method for producing a long-life, pressure-resistant graphite crucible, characterized in that: The steps include: S1. Raw material preparation: flake graphite with a particle size of 8-14 μm, medium-temperature asphalt, and silicon carbide are added to a kneading pot (2) in a mass ratio of 75:14:11 and mixed, and stirred at 180-220 ° C for 1-2 hours to form a homogeneous mixture; S2. Isostatic pressing: the mixture is poured into the lower hopper (4) and conveyed to the weighing hopper (6) by the screw conveyor (5) for weighing. After the weighing requirement is reached, the gate valve (60) is opened by the controller, and the mixture is added to the mold (100). The mold (100) is then conveyed to the bottom of the pressure forming machine (8) by the mold moving mechanism (7). The pressure forming machine (8) applies an isostatic pressure of 150-250 MPa and maintains the pressure for 10-30 minutes to obtain a graphite crucible green body; S3 stepped calcination: heating at a rate of 10-15 ℃ / h to 800-1000 ℃, holding for 20-40 hours, then heating at 5-8 ℃ / h to 1200-1300 ℃ for secondary calcination, a total calcination time of 80-120 hours; S4 vacuum impregnation treatment: The calcined body is placed in a vacuum impregnation tank, liquid phenolic resin is injected under a vacuum degree of 0.08-0.1MPa, and pressurized to 1.5-2.5MPa for 4-8 hours; S5. Gradient graphitization: Under argon protection, heat up to 2400-2800°C at 20-50°C / h and keep at this temperature for 10-20 hours; S6. Precision machining: Use CNC machine tools for turning of internal and external surfaces, and control the surface roughness at Ra ≤ 3.2μm.

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