Bell furnace for producing hexagonal boron nitride

Abstract

The invention relates to the technical field of hexagonal boron nitride production equipment, in particular to a bell jar furnace for producing hexagonal boron nitride, which comprises a shell, a calcining mechanism is mounted in the shell, the calcining mechanism comprises a furnace platform, the furnace platform is fixedly mounted at the bottom of the shell, and a vertical lifting device is arranged at the top of the furnace platform. A bearing table is arranged on the surface of the vertical lifting device, the guide rail is fixedly installed on the top of the bearing table, a feeding frame is slidably installed in the guide rail, and the hearth is fixedly installed in the shell. Through the arrangement of the calcining mechanism, the gas inlet amount of the gas storage tank can be changed, micro-positive pressure inert atmosphere needs to be maintained for a long time during bell-type furnace production, high-pressure gas of the corresponding volume needs to be accurately supplemented, it is ensured that the hearth pressure is always stabilized in a target interval, oxidation type quality defects are fundamentally avoided, inert gas consumption is reduced, and the operation cost is remarkably saved; severe fluctuation of hearth pressure is avoided, and temperature field uniformity and equipment stability are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hexagonal boron nitride production equipment technology, specifically a bell-shaped furnace for producing hexagonal boron nitride. Background Technology

[0002] Hexagonal boron nitride, an advanced ceramic material with excellent high-temperature resistance, insulation, thermal conductivity, and chemical stability, is widely used in high-end fields such as semiconductor packaging, high-temperature lubrication, and heat dissipation devices. Its production process requires extremely stringent reaction environments. The key is that high-temperature calcination must be completed under a slightly positive pressure inert atmosphere. The inert atmosphere isolates the raw materials and products from air, preventing oxidation, while the slightly positive pressure prevents backflow of external air and ensures the smooth removal of volatile impurities during the reaction. This directly determines the purity, crystallinity, and mechanical properties of hexagonal boron nitride.

[0003] Most existing bell-shaped furnaces adopt a fixed-flow gas replenishment mode, which involves continuously introducing a constant flow of inert gas into the furnace through a gas storage tank to maintain the furnace pressure. However, during the calcination of hexagonal boron nitride, the furnace pressure will dynamically change due to factors such as temperature fluctuations, release of volatiles from raw materials, and slight leaks in the furnace body. When the furnace pressure is lower than the target slightly positive pressure range, the fixed-flow gas replenishment cannot quickly and accurately replenish the pressure, which can easily lead to air backflow through the furnace door sealing gaps and pipe interfaces. After mixing with the inert atmosphere, it will cause the raw materials to oxidize, resulting in unqualified products with excessive oxygen content. Summary of the Invention

[0004] To overcome the above deficiencies, the present invention provides a bell furnace for producing hexagonal boron nitride that overcomes or at least partially solves the above technical problems.

[0005] This invention is implemented as follows: This invention provides a bell-shaped furnace for producing hexagonal boron nitride, comprising an outer shell, wherein a calcination mechanism is installed inside the outer shell, the calcination mechanism comprising: A furnace platform is fixedly installed at the bottom of the outer shell, and a vertical lifting device is provided on the top of the furnace platform. A support platform is provided on the surface of the vertical lifting device. The guide rail is fixedly installed on the top of the support platform, and a feeding rack is slidably installed inside the guide rail; The furnace chamber is fixedly installed inside the outer shell, and heating wires are fixedly installed on the inner wall of the furnace chamber. A fan is fixedly installed on the top of the inner wall of the furnace chamber.

[0006] In one embodiment of the present invention, a connecting port is provided on both sides of the furnace. A branch pipe is fixedly installed on the side of the connecting port, and a main pipe is fixedly installed on the side of the branch pipe. A piston plate is slidably installed inside the main pipe. There are two piston plates. A first sliding rod is fixedly installed on the side of the front piston plate, and a first sliding cylinder is fixedly installed on the side of the rear piston plate. The first sliding rod passes through the side of the rear piston plate and is slidably connected to the first sliding cylinder. A first connecting plate is fixedly installed at the end of the first sliding cylinder, and a second connecting plate is fixedly installed at the end of the first sliding rod.

[0007] In one embodiment of the present invention, a first mounting plate is fixedly installed on the outside of the furnace chamber, a rotating disk is rotatably installed on the surface of the first mounting plate, a second mounting plate is fixedly installed on the outside of the furnace chamber, a first rotating plate is rotatably installed on the top of the second mounting plate, a second rotating plate is rotatably installed on the bottom of the first mounting plate, and the second rotating plate is fixedly connected to the rotating disk.

[0008] In one embodiment of the present invention, a first fixing plate is rotatably mounted on the surface of the first connecting plate, and the end of the first fixing plate is rotatably connected to the first rotating plate. A second fixing plate is rotatably mounted on the surface of the second connecting plate, and the end of the second fixing plate is rotatably connected to the second rotating plate. A support plate is rotatably connected between the first fixing plate and the second fixing plate.

[0009] In one embodiment of the present invention, a vent is provided at the rear of the furnace, a disc is rotatably mounted on the surface of the vent, an arc-shaped groove is provided on the surface of the disc, and multiple arc-shaped grooves are provided. An arc-shaped plate is rotatably mounted on the surface of the disc, and multiple arc-shaped plates are provided. A stop block is fixedly mounted at the end of each of the multiple arc-shaped plates, and the stop block is rotatably connected to the surface of the disc.

[0010] In one embodiment of the present invention, a gas storage tank is provided inside the outer shell, a fixed plate is provided at the gas outlet of the gas storage tank, an mounting column is fixedly installed on the side of the fixed plate, the mounting column is slidably connected to the arc groove, the fixed plate is rotatably connected to the disc, an eccentric plate is rotatably installed at the eccentric part of the disc, a first sliding groove is provided on the surface of the furnace, a first toothed plate is slidably installed inside the first sliding groove, a toothed ring is provided on the surface of the disc, the first toothed plate meshes with the toothed ring, and the first toothed plate is rotatably connected to the eccentric plate.

[0011] In one embodiment of the present invention, a pressure relief mechanism is provided at the front of the furnace chamber. The pressure relief mechanism includes a second sliding rod, which is fixedly installed on the side of the front piston plate. The end of the second sliding rod is provided with a threaded groove. A first mounting seat is fixedly installed on the outer surface of the furnace chamber. A first pulley is rotatably installed on the surface of the first mounting seat. The end of the second sliding rod is threadedly connected to the first pulley.

[0012] In one embodiment of the present invention, a first gear is rotatably mounted on the front part of the furnace chamber, a second pulley is fixedly mounted on the surface of the first gear, the second pulley is connected to the first pulley via a belt, a second gear is rotatably mounted on the surface of the furnace chamber, the second gear meshes with the first gear, and a color plate is rotatably mounted on the surface of the outer shell, the color plate is fixedly connected to the second gear.

[0013] In one embodiment of the present invention, a second sliding groove is provided at the front of the furnace chamber, a double-toothed plate is slidably installed inside the second sliding groove, the double-toothed plate meshes with a first gear, a second mounting seat is fixedly installed at the front of the furnace chamber, a second sliding cylinder is fixedly installed on the side of the second mounting seat, a third sliding rod is slidably installed inside the second sliding cylinder, the third sliding rod is fixedly connected to the double-toothed plate, a spring is provided between the double-toothed plate and the second mounting seat, and a pressing rod is fixedly installed on the side of the double-toothed plate.

[0014] In one embodiment of the present invention, a push button is fixedly installed at the front of the furnace chamber, a third gear is rotatably installed at the front of the furnace chamber, the third gear meshes with a double-tooth plate, a threaded cylinder is fixedly installed on the side of the third gear, a threaded rod is installed on the internal thread of the threaded cylinder, a top plate is fixedly installed at the end of the threaded rod, a plug is fixedly installed on the side of the top plate, a pressure relief pipe is fixedly installed at the front of the furnace chamber, the pressure relief pipe is slidably connected to the plug, and a pressure relief port is provided on the surface of the pressure relief pipe, and multiple pressure relief ports are provided.

[0015] The present invention provides a bell-shaped furnace for producing hexagonal boron nitride, the beneficial effects of which include: 1. This invention, through the design of the calcination mechanism, allows for the modification of the gas intake of the gas storage tank. The tank uses high-pressure gas to compensate for any decrease in furnace pressure. When the furnace pressure returns to normal under the action of the gas storage tank, the two piston plates move in opposite directions, causing the gas outlet of the tank to close. The bell-shaped furnace production requires maintaining a slightly positive pressure inert atmosphere for an extended period to isolate air, precisely replenish the corresponding volume of high-pressure gas, ensure the furnace pressure remains stable within the target range, prevent backflow of air, and guarantee that the material reacts in a pure inert atmosphere. This fundamentally avoids oxidation-related quality defects, reduces inert gas consumption, significantly saves operating costs, prevents drastic fluctuations in furnace pressure, and ensures temperature uniformity and equipment stability.

[0016] 2. This invention uses a color-coded display panel to visually indicate the pressure inside the furnace. In workshops involving multiple roles such as operators, inspectors, technicians, and maintenance personnel, traditional digital displays may lead to low collaboration efficiency due to differences in job roles. The color-coded display panel, through a unified visual language, ensures that all roles have consistent standards for judging the pressure status, eliminating the need for additional communication.

[0017] 3. This invention, through the setting of the pressure relief mechanism, can control the pressure relief rate according to the pressure magnitude. When the furnace pressure is much higher than the safety value, a fixed small flow rate for pressure relief will cause the pressure relief rate to be less than the pressure rise rate, resulting in continuous overpressure, triggering the safety valve to open forcibly, and even damaging the furnace body sealing structure. When the furnace pressure is close to the safety lower limit, a fixed large flow rate for pressure relief will quickly draw the pressure to negative pressure. Outside air will backflow through the furnace door sealing ring and pipe interface, mixing with the inert atmosphere inside the furnace, causing material oxidation. By controlling the pressure relief amount according to the pressure magnitude, the opening of the proportional pressure relief valve can be dynamically adjusted to ensure that the pressure relief rate is precisely matched with the pressure change. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure provided by an embodiment of the present invention; Figure 2 A schematic diagram of the calcination mechanism provided for an embodiment of the present invention; Figure 3 A schematic diagram of the rear structure of the furnace provided for an embodiment of the present invention; Figure 4A schematic diagram of the pressure relief mechanism provided for an embodiment of the present invention; Figure 5 A schematic diagram of the internal structure of the supervisor provided for an embodiment of the present invention; Figure 6 A schematic diagram of the internal structure of the furnace provided for an embodiment of the present invention; Figure 7 A schematic diagram of a disk structure provided for an embodiment of the present invention; Figure 8 Provided for the embodiments of the present invention Figure 2 Enlarged structural diagram of section A in the middle; Figure 9 Provided for the embodiments of the present invention Figure 4 Enlarged structural diagram of section A in the middle.

[0020] In the diagram: 1. Outer shell; 2. Calcination mechanism; 201. Furnace platform; 202. Vertical lifting device; 203. Support platform; 204. Guide rail; 205. Furnace chamber; 206. Heating wire; 207. Fan; 208. Connecting port; 209. Branch pipe; 210. Main pipe; 211. Piston plate; 213. First sliding rod; 214. First sliding cylinder; 215. First connecting plate; 216. Second connecting plate; 217. First mounting plate; 218. Rotating disk; 219. Second mounting plate; 220. First rotating plate; 221. Second rotating plate; 222. First fixing plate; 223. Second fixing plate; 224. Support plate; 225. Vent; 226. Disc; 227. Arc groove; 228. Arc plate; 229. Stop block; 230. Gas storage tank; 231. 1. Fixed plate; 232. Mounting column; 233. Eccentric plate; 234. First toothed plate; 235. Toothed ring; 236. First sliding groove; 237. Feeding rack; 3. Pressure relief mechanism; 301. Second sliding rod; 302. Threaded groove; 303. First mounting base; 304. First pulley; 305. First gear; 306. Second pulley; 307. Second gear; 308. Color plate; 309. Second sliding groove; 310. Double toothed plate; 311. Second mounting base; 312. Second sliding cylinder; 313. Third sliding rod; 314. Spring; 315. Pressing rod; 316. Pressing button; 317. Third gear; 318. Threaded cylinder; 319. Threaded rod; 320. Top plate; 321. Plug head; 322. Pressure relief port; 323. Pressure relief pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Reference Figures 1-9This technical solution provides a bell-shaped furnace for producing hexagonal boron nitride, specifically including an outer shell 1. A calcination mechanism 2 is installed inside the outer shell 1. The calcination mechanism 2 includes a furnace platform 201, a guide rail 204, and a furnace chamber 205. The furnace platform 201 is fixedly installed at the bottom of the outer shell 1. A vertical lifting device 202 is installed at the top of the furnace platform 201. A support platform 203 is installed on the surface of the vertical lifting device 202. The guide rail 204 is fixedly installed on the top of the support platform 203. A feeding rack 237 is slidably installed inside the guide rail 204. During production, the operator places the hexagonal boron nitride production raw material onto the top of the feeding rack 237, and then activates the vertical lifting device 202 to raise the entire support platform 203 into the furnace chamber 205. The furnace chamber 205 and the support platform 203 are connected. The joints of the platform 203 are filled with high-temperature resistant sealing material to ensure a sealed environment between the furnace chamber 205 and the platform 203. The furnace chamber 205 is fixedly installed inside the outer shell 1. Heating wires 206 are fixedly installed on the inner wall of the furnace chamber 205, and a fan 207 is fixedly installed on the top of the inner wall of the furnace chamber 205. During production, the heating wires 206 inside the furnace chamber 205 can rapidly raise the temperature inside the furnace chamber 205. Then, the fan 207 is activated to evenly distribute the temperature inside the furnace chamber 205. The fan blades and bearings of the fan 207 are made of high-temperature resistant material, and the motor of the fan 207 is located inside the heat insulation groove to prevent high temperatures from affecting the motor. As the heating time increases, the furnace chamber 205... The internal pressure will also change accordingly. Both sides of the furnace 205 have connecting ports 208. A branch pipe 209 is fixedly installed on the side of each connecting port 208, and a main pipe 210 is fixedly installed on the side of each branch pipe 209. A piston plate 211 is slidably installed inside the main pipe 210. Two piston plates 211 are provided, positioned between the two connecting ports 208. When the internal pressure of the furnace 205 changes, the positions of the two piston plates 211 inside the main pipe 210 also change. A first sliding rod 213 is fixedly installed on the side of the front piston plate 211, and a first sliding cylinder 214 is fixedly installed on the side of the rear piston plate 211. The first sliding rod 213 extends through the side of the rear piston plate 211 and is connected to the first sliding cylinder. A sliding connection is used. A first connecting plate 215 is fixedly installed at the end of the first sliding cylinder 214, and a second connecting plate 216 is fixedly installed at the end of the first sliding rod 213. A first mounting plate 217 is fixedly installed on the outside of the furnace 205. A rotating disk 218 is rotatably installed on the surface of the first mounting plate 217. A second mounting plate 219 is fixedly installed on the outside of the furnace 205. A first rotating plate 220 is rotatably installed on the top of the second mounting plate 219, and a second rotating plate 221 is rotatably installed on the bottom of the first mounting plate 217. The second rotating plate 221 is fixedly connected to the rotating disk 218. Under normal conditions, the pressure inside the furnace 205 is greater than atmospheric pressure but falls within a certain range. This pressure is within the appropriate range for hexagonal boron nitride production.When the pressure inside the furnace 205 decreases, the piston plates 211 move away from each other, causing the first sliding cylinder 214 and the first sliding rod 213 to slide. This changes the positions of the first connecting plate 215 and the second connecting plate 216, causing the first rotating plate 220 and the second rotating plate 221 to rotate. The rotation of the second rotating plate 221 drives the rotating disk 218 to rotate.

[0023] Reference Figures 1-9This embodiment also proposes that a first fixing plate 222 is rotatably mounted on the surface of the first connecting plate 215, and the end of the first fixing plate 222 is rotatably connected to the first rotating plate 220. A second fixing plate 223 is rotatably mounted on the surface of the second connecting plate 216, and the end of the second fixing plate 223 is rotatably connected to the second rotating plate 221. A support plate 224 is rotatably connected between the first fixing plate 222 and the second fixing plate 223. A vent 225 is provided at the rear of the furnace 205. A disc 226 is rotatably mounted on the surface of the vent 225. An arc-shaped groove 227 is provided on the surface of the disc 226. Multiple arc-shaped grooves 227 are provided. An arc-shaped plate 228 is rotatably mounted on the surface of the disc 226. The arc-shaped plate 228 is provided with... Multiple arc-shaped plates 228 are fixedly mounted with stop blocks 229 at their ends. The stop blocks 229 are rotatably connected to the surface of the disc 226. A gas storage tank 230 is provided inside the outer shell 1. A fixed plate 231 is provided at the gas outlet of the gas storage tank 230. A mounting column 232 is fixedly mounted on the side of the fixed plate 231. The mounting column 232 is slidably connected to the arc-shaped groove 227. The fixed plate 231 is rotatably connected to the disc 226. An eccentric plate 233 is rotatably mounted at the eccentric part of the rotating disc 218. A first sliding groove 236 is opened on the surface of the furnace 205. A first toothed plate 234 is slidably mounted inside the first sliding groove 236. A toothed ring 235 is provided on the surface of the disc 226. The first toothed plate 234 meshes with the toothed ring 235. The first toothed plate 234 is rotatably connected to the eccentric plate 233. When the rotating disk 218 rotates, it can drive the eccentric plate 233 to rotate, which in turn drives the first toothed plate 234 to slide inside the first sliding groove 236. The sliding of the first toothed plate 234 can drive the toothed ring 235 to rotate, which in turn drives the disk 226 to rotate. The rotation of the disk 226 can drive the arc plate 228 to rotate, and the rotating arc plate 228 can drive the stop block 229 to rotate on the surface of the disk 226. When the stop block 229 rotates, it can change the size of the air outlet of the gas storage tank 230, thereby changing the air intake of the gas storage tank 230. The internal structure of the gas storage tank 230 adopts... High-pressure gas is used to compensate for the decrease in internal pressure of furnace 205. When the internal pressure of furnace 205 returns to normal under the action of gas storage tank 230, the two piston plates 211 move in opposite directions, thereby reducing the gas outlet of gas storage tank 230 to a closed state. The bell furnace production needs to maintain a slightly positive pressure inert atmosphere for a long time. The purpose is to isolate air, accurately replenish the corresponding volume of high-pressure gas, ensure that the pressure of furnace 205 is always stable within the target range, 100% isolate air backflow, ensure that the material reacts in a pure inert atmosphere, avoid oxidation-related quality defects from the root, reduce inert gas consumption, significantly save operating costs, avoid drastic pressure fluctuations in furnace 205, and ensure temperature field uniformity and equipment stability.

[0024] Reference Figures 1-9This embodiment also proposes that a pressure relief mechanism 3 be provided at the front of the furnace 205. The pressure relief mechanism 3 includes a second sliding rod 301, which is fixedly installed on the side of the front piston plate 211. The end of the second sliding rod 301 is provided with a threaded groove 302. A first mounting seat 303 is fixedly installed on the outer surface of the furnace 205, and a first pulley 304 is rotatably installed on the surface of the first mounting seat 303. The end of the second sliding rod 301 is threadedly connected to the first pulley 304. When the pressure inside the furnace 205 is greater than the normal value, the front piston plate 211 moves towards the rear of the furnace 205, which in turn drives the second sliding rod 301 to move, thereby allowing the threaded groove 302 at the end of the second sliding rod 301 to... The first pulley 304 rotates internally, causing it to move. A first gear 305 is rotatably mounted on the front of the furnace 205. A second pulley 306 is fixedly mounted on the surface of the first gear 305 and connected to the first pulley 304 via a belt. A second gear 307 is rotatably mounted on the surface of the furnace 205 and meshes with the first gear 305. A color plate 308 is rotatably mounted on the surface of the outer casing 1 and is fixedly connected to the second gear 307. The rotation of the first pulley 304 drives the second pulley 306 to rotate, which in turn drives the first gear 305 to rotate. The first gear 305 can drive the second gear 307 to rotate, which in turn drives the color plate 308 to rotate. Workers can judge the pressure inside the furnace 205 by observing the rotation of the color plate 308. The simple color plate 308 can convey information more conveniently than a pressure gauge, allowing for intuitive understanding of the pressure inside the furnace 205 without the need for dedicated personnel to check the pressure gauge. A second sliding groove 309 is provided at the front of the furnace 205. A double-toothed plate 310 is slidably installed inside the second sliding groove 309. The double-toothed plate 310 meshes with the first gear 305. The rotation of the first gear 305 drives the double-toothed plate 310 to slide within the second sliding groove 309. A second mounting base 311 is fixedly installed on the furnace chamber 205. A second sliding cylinder 312 is fixedly installed on the side of the second mounting base 311. A third sliding rod 313 is slidably installed inside the second sliding cylinder 312. The third sliding rod 313 is fixedly connected to a double-toothed plate 310. A spring 314 is provided between the double-toothed plate 310 and the second mounting base 311. A pressing rod 315 is fixedly installed on the side of the double-toothed plate 310. A pressing button 316 is fixedly installed on the front of the furnace chamber 205. When the double-toothed plate 310 slides inside the second sliding groove 309, it can stretch the spring 314. When the pressure inside the furnace chamber 205 reaches a certain level, the pressing rod 315 contacts the pressing button 316, and the pressing button 316 controls the operation of the entire device.When the pressing lever 315 contacts the pressing button 316, pressing the button 316 stops the entire device, preventing the pressure inside the furnace 205 from continuing to increase and causing an accident. A third gear 317 is rotatably mounted on the front of the furnace 205. The third gear 317 meshes with the double toothed plate 310. A threaded cylinder 318 is fixedly mounted on the side of the third gear 317. A threaded rod 319 is threaded inside the threaded cylinder 318. A top plate 320 is fixedly mounted on the end of the threaded rod 319. A plug head 321 is fixedly installed on the side of the top plate 320, and a pressure relief pipe 323 is fixedly installed on the front of the furnace 205. The pressure relief pipe 323 is slidably connected to the plug head 321. A pressure relief port 322 is opened on the surface of the pressure relief pipe 323. Multiple pressure relief ports 322 are provided. When the double toothed plate 310 slides inside the second sliding groove 309, it can drive the third gear 317 to rotate. The rotating third gear 317 can drive the threaded cylinder 318 to rotate. 318 allows the threaded rod 319 to move inside the threaded cylinder 318, causing the position of the plug head 321 inside the pressure relief pipe 323 to change. This allows the pressure inside the furnace 205 to be released through the pressure relief port 322 on the surface of the pressure relief pipe 323. The released gas is treated by an external exhaust gas treatment device. The pressure relief port 322 allows the pressure relief rate to be controlled according to the pressure magnitude. When the pressure in the furnace 205 is much higher than the safe value, a fixed small-flow pressure relief will cause the pressure relief rate to be less than the pressure rise rate, resulting in continuous overpressure, triggering the safety valve to open forcibly, and even damaging the furnace body sealing structure. When the pressure in the furnace 205 approaches the safe lower limit, a fixed large-flow pressure relief will quickly draw the pressure to negative pressure. Outside air will backflow through the furnace door seal and pipe interfaces, mixing with the inert atmosphere inside the furnace, causing material oxidation. Controlling the pressure relief amount according to the pressure magnitude allows for dynamic adjustment of the opening of the proportional pressure relief valve, ensuring precise matching between the pressure relief rate and pressure changes.

[0025] Specifically, the working process or principle of this bell-shaped furnace for producing hexagonal boron nitride is as follows: During production, the operator places the hexagonal boron nitride raw material on the top of the feeding rack 237, and then activates the vertical lifting device 202 to raise the entire support platform 203 into the furnace chamber 205. The joint between the furnace chamber 205 and the support platform 203 is filled with a high-temperature resistant sealing material to ensure a sealed state. During production, the heating wire 206 inside the furnace chamber 205 rapidly raises the temperature inside. Then, the fan 207 is activated to evenly distribute the temperature inside the furnace chamber 205. The fan blades and bearings of the fan 207 are made of high-temperature resistant materials, and the motor of the fan 207 is located inside an insulation groove to prevent high temperatures from affecting the motor. As the heating time increases, the furnace... The pressure inside the furnace 205 will also change accordingly. Two piston plates 211 are set between two connecting ports 208. When the internal pressure of the furnace 205 changes, the position of the two piston plates 211 inside the main pipe 210 will also change. Under normal circumstances, the pressure inside the furnace 205 is greater than the atmospheric pressure and is within a certain range. At this time, the pressure is within the appropriate range for the production of hexagonal boron nitride. When the pressure inside the furnace 205 decreases, the piston plates 211 move away from each other, causing the first sliding cylinder 214 and the first sliding rod 213 to slide. This causes the position of the first connecting plate 215 and the second connecting plate 216 to change. The change in the position of the first connecting plate 215 and the second connecting plate 216 causes the first rotating plate 220 and the second rotating plate 221 to rotate. The rotation of the second rotating plate 221 can drive the rotating disk 218 to rotate.

[0026] When the rotating disk 218 rotates, it drives the eccentric plate 233 to rotate, which in turn drives the first toothed plate 234 to slide inside the first sliding groove 236. The sliding of the first toothed plate 234 drives the toothed ring 235 to rotate, which in turn drives the disk 226 to rotate. The rotation of the disk 226 drives the arc plate 228 to rotate, and the rotating arc plate 228 drives the stop block 229 to rotate on the surface of the disk 226. When the stop block 229 rotates, it can change the size of the gas outlet of the gas storage tank 230, thereby changing the gas intake of the gas storage tank 230. The gas storage tank 230 uses high-pressure gas to supplement the furnace. As the internal pressure of furnace 205 decreases, when the pressure inside furnace 205 returns to normal under the action of gas storage tank 230, the two piston plates 211 move in opposite directions, thereby reducing the gas outlet of gas storage tank 230 to a closed state. The bell furnace production needs to maintain a slightly positive pressure inert atmosphere for a long time. The purpose is to isolate air, accurately replenish the corresponding volume of high-pressure gas, ensure that the pressure of furnace 205 is always stable within the target range, 100% isolate air backflow, ensure that the material reacts in a pure inert atmosphere, avoid oxidation-related quality defects from the root, reduce inert gas consumption, significantly save operating costs, avoid drastic pressure fluctuations in furnace 205, and ensure temperature field uniformity and equipment stability.

[0027] When the pressure inside the furnace 205 exceeds the normal value, the piston plate 211 at the front moves towards the rear of the furnace 205, thereby driving the second sliding rod 301 to move. This causes the threaded groove 302 at the end of the second sliding rod 301 to move inside the first pulley 304, causing the first pulley 304 to rotate. The rotation of the first pulley 304 drives the second pulley 306 to rotate, which in turn drives the first gear 305 to rotate. The rotation of the first gear 305 drives the second gear 307 to rotate, which in turn drives the color plate 308 to rotate. Workers can judge the pressure inside the furnace 205 by observing the rotation of the color plate 308. The simple color plate 308 can convey more convenient information than a pressure gauge, allowing for a direct understanding of the pressure inside the furnace 205 without the need for dedicated personnel to check the pressure gauge.

[0028] When the double-toothed plate 310 slides inside the second sliding groove 309, it can stretch the spring 314. When the pressure inside the furnace 205 reaches a certain level, the pressing rod 315 contacts the pressing button 316. The pressing button 316 controls the operation of the entire device. When the pressing rod 315 contacts the pressing button 316, the pressing button 316 stops the entire device to prevent the pressure inside the furnace 205 from continuing to increase and causing an accident. When the double-toothed plate 310 slides inside the second sliding groove 309, it can drive the third gear 317 to rotate. The rotating third gear 317 can drive the threaded cylinder 318 to rotate. The rotating threaded cylinder 318 can cause the threaded rod 319 to move inside the threaded cylinder 318, so that the position of the plug head 321 inside the pressure relief pipe 323 is adjusted. The pressure inside the furnace 205 changes, allowing the pressure to be released through the pressure relief port 322 on the surface of the pressure relief pipe 323. The released gas is then treated by an external exhaust gas treatment device. The pressure relief port 322 allows the pressure relief rate to be controlled according to the pressure. When the pressure in the furnace 205 is much higher than the safety value, a fixed small flow rate pressure relief will cause the pressure relief rate to be less than the pressure rise rate, resulting in continuous overpressure, triggering the safety valve to open forcibly, and even damaging the furnace body sealing structure. When the pressure in the furnace 205 approaches the safety lower limit, a fixed large flow rate pressure relief will quickly draw the pressure to negative pressure. Outside air will backflow through the furnace door seal and pipe interface, mixing with the inert atmosphere inside the furnace, causing the material to oxidize. Controlling the pressure relief amount according to the pressure can dynamically adjust the opening of the proportional pressure relief valve to ensure that the pressure relief rate is precisely matched with the pressure change.

Claims

1. A bell-shaped furnace for producing hexagonal boron nitride, comprising an outer shell (1), characterized in that, A calcination mechanism (2) is installed inside the outer shell (1), and the calcination mechanism (2) includes: A furnace platform (201) is fixedly installed at the bottom of the outer shell (1). A vertical lifting device (202) is provided on the top of the furnace platform (201), and a support platform (203) is provided on the surface of the vertical lifting device (202). Guide rail (204), the guide rail (204) is fixedly installed on the top of the support platform (203), and a feeding rack (237) is slidably installed inside the guide rail (204). The furnace chamber (205) is fixedly installed inside the outer shell (1). Heating wires (206) are fixedly installed on the inner wall of the furnace chamber (205). A fan (207) is fixedly installed on the top of the inner wall of the furnace chamber (205).

2. The bell-shaped furnace for producing hexagonal boron nitride according to claim 1, characterized in that, Both sides of the furnace (205) are provided with connecting ports (208). A branch pipe (209) is fixedly installed on the side of the connecting port (208). A main pipe (210) is fixedly installed on the side of the branch pipe (209). A piston plate (211) is slidably installed inside the main pipe (210). There are two piston plates (211). A first sliding rod (213) is fixedly installed on the side of the front piston plate (211). A first sliding cylinder (214) is fixedly installed on the side of the rear piston plate (211). The first sliding rod (213) passes through to the side of the rear piston plate (211) and is slidably connected to the first sliding cylinder (214). A first connecting plate (215) is fixedly installed at the end of the first sliding cylinder (214). A second connecting plate (216) is fixedly installed at the end of the first sliding rod (213).

3. A bell-shaped furnace for producing hexagonal boron nitride according to claim 2, characterized in that, A first mounting plate (217) is fixedly installed on the outside of the furnace chamber (205). A rotating disk (218) is rotatably installed on the surface of the first mounting plate (217). A second mounting plate (219) is fixedly installed on the outside of the furnace chamber (205). A first rotating plate (220) is rotatably installed on the top of the second mounting plate (219). A second rotating plate (221) is rotatably installed on the bottom of the first mounting plate (217). The second rotating plate (221) is fixedly connected to the rotating disk (218).

4. A bell-shaped furnace for producing hexagonal boron nitride according to claim 3, characterized in that, A first fixing plate (222) is rotatably mounted on the surface of the first connecting plate (215), and the end of the first fixing plate (222) is rotatably connected to the first rotating plate (220). A second fixing plate (223) is rotatably mounted on the surface of the second connecting plate (216), and the end of the second fixing plate (223) is rotatably connected to the second rotating plate (221). A support plate (224) is rotatably connected between the first fixing plate (222) and the second fixing plate (223).

5. A bell-shaped furnace for producing hexagonal boron nitride according to claim 4, characterized in that, The furnace (205) has a vent (225) at the rear. A disc (226) is rotatably mounted on the surface of the vent (225). An arc groove (227) is provided on the surface of the disc (226). Multiple arc grooves (227) are provided. An arc plate (228) is rotatably mounted on the surface of the disc (226). Multiple arc plates (228) are provided. A stop block (229) is fixedly mounted at the end of each of the multiple arc plates (228). The stop block (229) is rotatably connected to the surface of the disc (226).

6. A bell-shaped furnace for producing hexagonal boron nitride according to claim 5, characterized in that, The outer shell (1) is provided with a gas storage tank (230) inside. The gas outlet of the gas storage tank (230) is provided with a fixed plate (231). The side of the fixed plate (231) is fixedly installed with a mounting column (232). The mounting column (232) is slidably connected to the arc groove (227). The fixed plate (231) is rotatably connected to the disc (226). An eccentric plate (233) is rotatably installed at the eccentric part of the rotating disc (218). The surface of the furnace (205) is provided with a first sliding groove (236). The first toothed plate (234) is slidably installed inside the first sliding groove (236). The surface of the disc (226) is provided with a toothed ring (235). The first toothed plate (234) meshes with the toothed ring (235). The first toothed plate (234) is rotatably connected to the eccentric plate (233).

7. A bell-shaped furnace for producing hexagonal boron nitride according to claim 6, characterized in that, The furnace chamber (205) is provided with a pressure relief mechanism (3) at the front. The pressure relief mechanism (3) includes a second sliding rod (301). The second sliding rod (301) is fixedly installed on the side of the front piston plate (211). The end of the second sliding rod (301) is provided with a threaded groove (302). The outer surface of the furnace chamber (205) is fixedly installed with a first mounting seat (303). The surface of the first mounting seat (303) is rotatably mounted with a first pulley (304). The end of the second sliding rod (301) is threadedly connected to the first pulley (304).

8. A bell-shaped furnace for producing hexagonal boron nitride according to claim 7, characterized in that, A first gear (305) is rotatably mounted on the front of the furnace chamber (205). A second pulley (306) is fixedly mounted on the surface of the first gear (305). The second pulley (306) is connected to the first pulley (304) via a belt. A second gear (307) is rotatably mounted on the surface of the furnace chamber (205). The second gear (307) meshes with the first gear (305). A color plate (308) is rotatably mounted on the surface of the outer shell (1). The color plate (308) is fixedly connected to the second gear (307).

9. A bell-shaped furnace for producing hexagonal boron nitride according to claim 8, characterized in that, The furnace chamber (205) has a second sliding groove (309) at the front. A double toothed plate (310) is slidably installed inside the second sliding groove (309). The double toothed plate (310) meshes with the first gear (305). A second mounting seat (311) is fixedly installed at the front of the furnace chamber (205). A second sliding cylinder (312) is fixedly installed on the side of the second mounting seat (311). A third sliding rod (313) is slidably installed inside the second sliding cylinder (312). The third sliding rod (313) is fixedly connected to the double toothed plate (310). A spring (314) is provided between the double toothed plate (310) and the second mounting seat (311). A pressing rod (315) is fixedly installed on the side of the double toothed plate (310).

10. A bell-shaped furnace for producing hexagonal boron nitride according to claim 9, characterized in that, A push button (316) is fixedly installed at the front of the furnace (205). A third gear (317) is rotatably installed at the front of the furnace (205). The third gear (317) meshes with a double toothed plate (310). A threaded cylinder (318) is fixedly installed on the side of the third gear (317). A threaded rod (319) is installed on the internal thread of the threaded cylinder (318). A top plate (320) is fixedly installed at the end of the threaded rod (319). A plug head (321) is fixedly installed on the side of the top plate (320). A pressure relief pipe (323) is fixedly installed at the front of the furnace (205). The pressure relief pipe (323) is slidably connected to the plug head (321). A pressure relief port (322) is opened on the surface of the pressure relief pipe (323). Multiple pressure relief ports (322) are provided.

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