A high-pressure vacuum electric melting furnace

Abstract

This utility model relates to the field of high-purity quartz glass processing, and specifically to a high-pressure vacuum electric melting furnace. The utility model includes a furnace body assembly, a hot zone assembly, a vacuum system, a pressurization system, a stirring mechanism, and a rotating mechanism. The furnace body assembly includes an upper furnace body, a lower furnace body, and a locking ring assembly, which seals the upper and lower furnace bodies. The hot zone assembly includes an upper insulation screen assembly, a middle insulation screen assembly, a lower insulation screen assembly, a main heater, and a bottom heater. The lower part of the hot zone assembly is limited by a hot zone fixing bracket, and the lower insulation screen assembly moves up and down via an insulation lifting assembly. The vacuum system includes a dry pump, a diffusion pump, a pre-evacuation valve, a high-pressure butterfly valve, a high-pressure valve, a pre-stage valve, a vacuum gauge, and a filter. The pressurization system includes a low-pressure tank, a high-pressure tank, a mass flow meter, a one-way valve, a high-pressure inlet valve, and a gas source. The stirring component in the stirring mechanism can move up and down to stir the material. The rotating component in the rotating mechanism drives the crucible to rotate via a motor.

Description

Technical Field

[0001] This utility model relates to the field of high-purity quartz glass processing, and specifically to a high-pressure vacuum electric melting furnace. Background Technology

[0002] In the existing field of high-purity quartz glass processing, traditional production processes struggle to effectively control the vacuum and pressure parameters within the furnace during melting. This leads to the formation of bubbles during quartz melting, which are difficult to remove, resulting in insufficient material density. Simultaneously, the cleanliness control of the thermal field structure is limited; conventional insulation materials easily shed slag, contaminating the raw materials and affecting the purity of the quartz glass. Furthermore, traditional equipment employs limited temperature gradient control methods, making directional solidification difficult and resulting in poor uniformity of quartz ingot crystallization, impacting product quality. To address these issues, this invention provides a high-purity quartz glass processing method that precisely controls process parameters and optimizes the thermal field structure using a high-pressure vacuum electric melting furnace, thereby improving material purity and production quality. Utility Model Content

[0003] This invention provides a high-pressure vacuum electric melting furnace to address the problems of existing technologies.

[0004] The objective of this utility model can be achieved through the following technical solutions:

[0005] A high-pressure vacuum electric melting furnace includes a furnace body assembly, a hot zone assembly, a vacuum system, a pressurization system, a stirring mechanism, and a rotating mechanism;

[0006] The furnace body assembly includes an upper furnace body, a lower furnace body, and a locking ring assembly, which seals the upper furnace body and the lower furnace body together.

[0007] The thermal field assembly includes an upper insulation screen assembly, a middle insulation screen assembly, a lower insulation screen assembly, a main heater, a bottom heater, and a top heater. The upper and middle insulation screen assemblies are connected by fixing bolts and fixed to the upper furnace body by four sets of hanging rod bolts. The bottom of the middle insulation screen assembly is fixed to the inner wall of the upper furnace body by a thermal field fixing bracket. The lower insulation screen assembly is fixed to the insulation lifting assembly on the lower furnace body and moves with the insulation lifting assembly.

[0008] The vacuum system includes a dry pump, a diffusion pump, a pre-evacuation valve, a high-pressure butterfly valve, a high-pressure valve, a fore-stage valve, a vacuum gauge, and a filter, used to create a vacuum environment inside the furnace.

[0009] The pressurization system includes a low-pressure tank, a high-pressure tank, a mass flow meter, a check valve, a high-pressure inlet valve, and a gas source, used to regulate the pressure inside the furnace;

[0010] The stirring component in the stirring mechanism can move up and down to stir the material.

[0011] The rotating component in the rotating mechanism drives the crucible to rotate via a motor.

[0012] Further improvements include an upper insulation screen assembly in the thermal field component comprising alternating layers of tungsten and molybdenum upper insulation screens from the inside out. Each layer of tungsten and molybdenum upper insulation screens is separated by tungsten-molybdenum grid strips and fixed by tungsten-molybdenum bolt assemblies. The uppermost molybdenum upper insulation screen is sequentially topped with an upper insulation ceramic insulation felt and an upper insulation welded frame. The middle insulation screen assembly comprises alternating layers of tungsten and molybdenum middle insulation screens from the inside out. Each layer of tungsten and molybdenum middle insulation screens is separated by tungsten-molybdenum grid strips and fixed by a middle insulation... The outermost middle insulation screen is fixed with tungsten-molybdenum bolts. A ceramic insulation felt and a welded frame are sequentially arranged around the outer side of the molybdenum screen. The lower insulation screen assembly includes alternating lower insulation screens of tungsten and molybdenum from the inside out. Each layer of lower insulation screen is separated by tungsten-molybdenum grid strips and fixed with tungsten-molybdenum bolts. A ceramic insulation felt and a welded frame are sequentially arranged at the lower end of the lowest molybdenum screen. The upper and lower insulation screen assemblies contain electrode holes and thermocouple holes with boron nitride ceramic tubes.

[0013] In a further improvement, the thermal field assembly also includes a gas guide hood assembly, which includes a molybdenum gas guide pipe, a gas guide hood, and a molybdenum baffle plate. The molybdenum gas guide pipe and the gas guide hood are fastened together by gas guide hood fixing screws. The molybdenum baffle plate is disposed in the gap between the gas guide hood cover and the molybdenum gas guide pipe. The gas guide hood assembly is fastened to the upper insulation screen welding frame by gas guide cylinder fixing screws and gas guide cylinder fixing adapter plate.

[0014] In a further improvement, the dry pump is connected in series with the pre-vacuum valve, diffusion pump, high-pressure valve, and high-pressure butterfly valve via a filter, ultimately forming a main vacuum pumping passage with the furnace assembly. The vacuum system also includes an electric exhaust valve and a vacuum pressure regulating valve. The electric exhaust valve is installed on the pipe section between the high-pressure butterfly valve and the furnace assembly. One end of the pre-vacuum valve is connected to the main vacuum passage between the furnace assembly and the high-pressure valve via a pipe, and the other end of the pre-vacuum valve is connected to the pipe between the pre-vacuum valve and the filter via a pipe. One end of the pre-vacuum valve is connected to the outlet of the diffusion pump, and the other end of the pre-vacuum valve is connected to the inlet of the filter. The vacuum pressure regulating valve is connected in parallel between the pipe connecting the pre-vacuum valve and the furnace assembly, and the pipe connecting the pre-vacuum valve and the filter. One end of the vacuum pressure regulating valve is connected to the main passage between the furnace assembly and the high-pressure valve, and the other end of the vacuum pressure regulating valve is connected to the pipe between the pre-vacuum valve and the filter. The vacuum gauge is connected in series with the pressure monitoring branch of the furnace assembly via a vacuum gauge isolation valve.

[0015] In a further improvement, the gas source is connected sequentially to the high-pressure inlet on / off valve via ball valve one, pressure regulating valve one, low-pressure tank, pressure regulating valve ball valve, mass flow meter, and check valve; simultaneously, the low-pressure tank is connected to the high-pressure tank in parallel via ball valve two, booster, and high-pressure ball valve one, and the high-pressure tank is connected to the high-pressure inlet on / off valve via high-pressure ball valve two; pressure sensors are installed at the gas inlet ends of the low-pressure tank, high-pressure tank, and furnace body assembly, and safety valves are installed in parallel at the top of the low-pressure tank and high-pressure tank.

[0016] Compared with existing technologies, the advantages of this high-pressure vacuum electric melting furnace are as follows:

[0017] The thermal field component adopts a composite insulation structure combining alternating layers of tungsten-molybdenum screens with ceramic insulation felt, avoiding contamination and improving insulation efficiency; the vacuum system achieves precise vacuum adjustment and safety protection through pre-evacuation valves and vacuum pressure valves; the pressurization system adopts a dual-mode gas supply of "low pressure-high pressure" to adapt to different process requirements; the insulation lifting component ensures accurate lifting of the insulation screen and adapts to high-pressure conditions through servo motor linkage control and magnetic fluid sealing technology. The whole system achieves directional solidification through vacuum pretreatment, stirring and rotation, pressure regulation up to 2MPa, and temperature gradient control by the lower insulation screen lifting device, effectively reducing bubbles, improving material density and crystallization uniformity, and increasing the purity of quartz glass. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the vacuum system and furnace body assembly in this utility model.

[0019] Figure 2 This is a schematic diagram of the pressurization system and furnace body assembly in this utility model.

[0020] Figure 3 This is a schematic diagram of the furnace body assembly in this utility model.

[0021] Figure 4 This is a schematic diagram of the structure of the thermal field component in this utility model.

[0022] Figure 5 This is a schematic diagram of the structure of the gas guide shroud assembly in this utility model.

[0023] Figure 6 This is a schematic diagram of the structure of the heat preservation and lifting component in this utility model.

[0024] In the diagram, 1-furnace body assembly, 11-upper furnace body, 12-lower furnace body, 13-locking ring assembly, 2-thermal zone assembly, 21-upper insulation screen assembly, 211-upper insulation screen tungsten screen, 212-upper insulation screen molybdenum screen, 213-upper insulation screen tungsten-molybdenum grid strip, 214-upper insulation screen tungsten-molybdenum bolt assembly, 215-upper insulation screen ceramic insulation felt, 216-upper insulation screen welded frame, 22-middle insulation screen assembly, 221-middle insulation screen tungsten screen, 222-middle insulation screen molybdenum screen, 223-middle insulation screen tungsten-molybdenum grid strip. 224-Tungsten-molybdenum bolt assembly for middle insulation screen; 225-Ceramic insulation felt for middle insulation screen; 226-Welded frame for middle insulation screen; 23-Lower insulation screen assembly; 231-Tungsten screen for lower insulation screen; 232-Molybdenum screen for lower insulation screen; 233-Tungsten-molybdenum grid strip for lower insulation screen; 234-Tungsten-molybdenum bolt assembly for lower insulation screen; 235-Ceramic insulation felt for lower insulation screen; 236-Welded frame for lower insulation screen; 24-Main heater; 25-Bottom heater; 251-Top heater; 26-Hanging rod bolt; 27-Hot field fixing bracket; 28- Fixed bolts, 29-boron nitride ceramic tube, 3-vacuum system, 31-dry pump, 32-diffusion pump, 33-pre-evacuation valve, 331-vacuum pressure regulating valve, 34-high pressure butterfly valve, 35-high pressure valve, 36-forward valve, 37-vacuum gauge, 371-vacuum gauge isolation valve, 38-filter, 39-electric exhaust valve, 4-pressurization system, 41-low pressure tank, 411-pressure regulating ball valve, 412-booster compressor, 413-pressure regulating valve one, 414-ball valve two, 42-high pressure tank, 421-high pressure ball valve one, 4 22-High-pressure ball valve II, 43-Mass flow meter, 44-Check valve, 45-High-pressure inlet shut-off valve, 46-Gas source, 461-Ball valve I, 47-Safety valve, 48-Pressure sensor, 5-Stirring mechanism, 51-Stirring assembly, 6-Rotating mechanism, 61-Rotating assembly, 7-Crucible, 8-Gas guide hood assembly, 81-Molybdenum gas guide pipe, 82-Gas guide hood, 83-Molybdenum baffle plate, 84-Gas guide hood fixing screw, 85-Gas guide cylinder fixing screw, 86-Gas guide cylinder fixing adapter plate, 9-Heating and lifting assembly. Detailed Implementation

[0025] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] The following is a description of the embodiments and appendices. Figures 1-6 The technical solution of this utility model will be further described below.

[0028] Example 1

[0029] A high-pressure vacuum electric melting furnace includes a furnace body assembly 1, a hot zone assembly 2, a vacuum system 3, a pressurization system 4, a stirring mechanism 5, and a rotating mechanism 6;

[0030] The furnace body assembly 1 includes an upper furnace body 11, a lower furnace body 12, and a locking ring assembly 13, which achieves the sealing between the upper furnace body 11 and the lower furnace body 12.

[0031] The thermal field assembly 2 includes an upper insulation screen assembly 21, a middle insulation screen assembly 22, a lower insulation screen assembly 23, a main heater 24, a bottom heater 25, and a top heater 251. The upper insulation screen assembly 21 and the middle insulation screen assembly 22 are connected by fixing bolts 28 and fixed inside the upper furnace body 11 by four sets of hanging bolts 26. The bottom of the middle insulation screen assembly 22 is fixed to the inner wall of the upper furnace body 11 by thermal field fixing brackets 27. The lower insulation screen assembly 23 is fixed to the insulation lifting assembly 9 on the lower furnace body 12 and moves with the insulation lifting assembly 9.

[0032] The vacuum system 3 includes a dry pump 31, a diffusion pump 32, a pre-evacuation valve 33, a high-pressure butterfly valve 34, a high-pressure valve 35, a pre-stage valve 36, a vacuum gauge 37, and a filter 38, which are used to create a vacuum environment inside the furnace.

[0033] The pressurization system 4 includes a low-pressure tank 41, a high-pressure tank 42, a mass flow meter 43, a one-way valve 44, a high-pressure inlet valve 45, and a gas source 46, which are used to regulate the pressure inside the furnace.

[0034] The stirring component 51 in the stirring mechanism 5 can move up and down to stir the material.

[0035] The rotating component 61 in the rotating mechanism 6 drives the crucible 7 to rotate via a motor.

[0036] The stirring assembly effectively removes air bubbles from the liquid, reducing their residue in the melt and improving the quality of the quartz glass. The pressurization system works synergistically with the stirring assembly in reducing bubbles; under pressure, the volume of bubbles in the melt is compressed, reducing the strength of the bubble walls and making them easier to break. Once a bubble breaks, the gas inside quickly dissolves in the melt or is expelled from the furnace under pressure, thus reducing the number of bubbles in the melt, significantly lowering the bubble rate in the finished product, and significantly improving density. During directional solidification, the effective reduction of bubbles from the initial stirring and pressure control steps allows the crystallization process to take place in a purer melt, ensuring the quality of the quartz ingot. The high-vacuum environment reduces oxidation reactions, and the thermal field uses a combination of tungsten-molybdenum metal screens and ceramic insulation felt to avoid slag contamination from traditional materials, achieving a quartz glass purity of over 99.99%.

[0037] As a further preferred embodiment, the upper insulation screen assembly 21 in the thermal field assembly 2 includes upper insulation screen tungsten screen 211 and upper insulation screen molybdenum screen 212 alternating from the inside to the outside. Each layer of upper insulation screen tungsten screen 211 and upper insulation screen molybdenum screen 212 is separated by upper insulation screen tungsten-molybdenum grid strips 213 and fixed by upper insulation screen tungsten-molybdenum bolt group 214. The uppermost upper insulation screen molybdenum screen 212 is provided with upper insulation screen ceramic insulation felt 215 and upper insulation screen welding frame 216 in sequence at its upper end. The middle insulation screen assembly 22 includes middle insulation screen tungsten screen 221 and middle insulation screen molybdenum screen 222 alternating from the inside to the outside. Each layer of middle insulation screen tungsten screen 221 and middle insulation screen molybdenum screen 222 is separated by middle insulation screen tungsten-molybdenum grid strips 223 and fixed by middle insulation screen tungsten-molybdenum bolt group 224. The outermost middle insulation screen molybdenum screen 222 The outer side is provided with a middle insulation screen ceramic insulation felt 225 and a middle insulation screen welded frame 226 in sequence; the lower insulation screen assembly 23 includes a lower insulation screen tungsten screen 231 and a lower insulation screen molybdenum screen 232 alternating from the inside to the outside. Each layer of lower insulation screen tungsten screen 231 and lower insulation screen molybdenum screen 232 is separated by a lower insulation screen tungsten molybdenum grid strip 233 and fixed by a lower insulation screen tungsten molybdenum bolt group 234. The lower end of the lower insulation screen molybdenum screen 232 is provided with a lower insulation screen ceramic insulation felt 235 and a lower insulation screen welded frame 236 in sequence; the upper insulation screen assembly 21 and the lower insulation screen assembly 23 are connected by fixing bolts 28. The bottom of the middle insulation screen assembly 22 is fixed to the inner wall of the furnace body assembly 1 by a thermal field fixing bracket 27. The upper insulation screen assembly 21 and the lower insulation screen assembly 23 are provided with electrode holes and thermocouple holes containing boron nitride ceramic tubes 29 inside.

[0038] The upper, middle, and lower insulation screens employ an alternating layered design of tungsten and molybdenum screens. The inner tungsten screen (high temperature resistance and high cleanliness) directly contacts the high-temperature molten metal, while the outer molybdenum screen (good insulation) reduces heat loss. Each layer is separated by tungsten-molybdenum grid strips to prevent direct contact between the metal screens and thermal short circuits. Ceramic insulation felt (specially treated to prevent slag shedding) wraps around the outside of the metal screens, and the outermost layer is fixed by a 316L welded frame, forming a composite structure of "metal screen insulation + ceramic insulation + frame support." Boron nitride ceramic tubes are embedded in the electrode holes and thermocouple holes, utilizing their high insulation and high temperature resistance (≥2200℃) to prevent short circuits between the electrodes and the furnace body, while also preventing corrosion of the temperature sensing elements by the molten metal. The cleanliness of the thermal field meets the requirements of high-purity quartz, improving insulation efficiency by 30%, controlling furnace temperature uniformity within ±5℃, and reducing energy consumption by 20%.

[0039] As a further preferred embodiment, the thermal field assembly 2 also includes a gas guide hood assembly 8, which includes a molybdenum gas guide pipe 81, a gas guide hood 82, and a molybdenum blocking plate 83. The molybdenum gas guide pipe 81 and the gas guide hood 82 are fastened together by gas guide hood fixing screws 84. The molybdenum blocking plate 83 is disposed in the gap between the upper cover of the gas guide hood 82 and the molybdenum gas guide pipe 81. The gas guide hood assembly 8 is fastened to the upper insulation screen welding frame 216 by gas guide cylinder fixing screws 85 and gas guide cylinder fixing adapter plate 86.

[0040] The molybdenum gas guide tube and the gas guide hood are fastened together with screws to form a protective gas passage. The molybdenum baffle covers the gap between the gas guide hood cover and the gas guide tube to prevent gas from directly scouring the surface of the melt and causing splashing. The gas guide hood assembly is fixed to the welding frame of the upper insulation screen. The gas is evenly diffused into the interior of the hot field through the gas guide hood to form a stable protective gas layer. The uniformity error of the protective gas is ≤5%, which effectively isolates air to prevent the melt from oxidizing. At the same time, the local temperature of the hot field can be assisted in adjusting the gas flow to improve the melting stability.

[0041] As a further preferred embodiment, the dry pump 31 is connected in series with the pre-stage valve 36, diffusion pump 32, high-pressure valve 35, and high-pressure butterfly valve 34 via the filter 38, ultimately forming a main vacuum pumping passage with the furnace body assembly 1. The vacuum system 3 also includes an electric exhaust valve 39 and a vacuum pressure regulating valve 331. The electric exhaust valve 39 is installed on the pipe section between the high-pressure butterfly valve 34 and the furnace body assembly 1. One end of the pre-extraction valve 33 is connected to the main vacuum passage between the furnace body assembly 1 and the high-pressure valve 35 via a pipe, and the other end of the pre-extraction valve 33 is connected to the pre-stage valve 36 and the filter via a pipe. The pipeline between 38, one end of the pre-valve 36 is connected to the outlet of the diffusion pump 32, and the other end of the pre-valve 36 is connected to the inlet of the filter 38. The vacuum pressure valve 331 is connected in parallel between the pre-extraction valve 33 and the furnace body assembly 1, and between the pre-valve 36 and the filter 38. One end of the vacuum pressure valve 331 is connected to the main passage between the furnace body assembly 1 and the high valve 35, and the other end of the vacuum pressure valve 331 is connected to the pipeline between the pre-valve 36 and the filter 38. The vacuum gauge 37 is connected in series to the pressure monitoring branch of the furnace body assembly 1 through the vacuum gauge isolation valve 371.

[0042] The first step is the pre-evacuation process:

[0043] Valve opening: Open the pre-extraction valve 33, the fore-stage valve 36, and the high-pressure butterfly valve 34. At this time, the dry pump 31, filter 38, fore-stage valve 36, diffusion pump 32, high-pressure valve 35, high-pressure butterfly valve 34, pre-extraction valve 33 and furnace body assembly 1 form a passage. The specific gas path is: gas in furnace body assembly 1 → pre-extraction valve 33 → fore-stage valve 36 → filter 38 → dry pump 31.

[0044] Evacuation operation: Dry pump 31 operates to pre-evacuate furnace body component 1, reducing the furnace pressure to 5 Pa. This process utilizes the evacuation capacity of dry pump 31 to rapidly reduce the furnace pressure, preparing for subsequent high-vacuum evacuation.

[0045] Then comes the emptying process:

[0046] Valve switching and diffusion pump preparation: After pre-evacuation is completed, heat diffusion pump 32 for 30 minutes until it reaches operating temperature. Then close pre-evacuation valve 33 and open high-pressure valve 35 and fore-stage valve 36. At this time, the gas path becomes: gas in furnace assembly 1 → high-pressure valve 35 → diffusion pump 32 → fore-stage valve 36 → filter 38 → dry pump 31.

[0047] High vacuum evacuation: Dry pump 31 and diffusion pump 32 work together to evacuate the furnace body component 1, further improving the vacuum level inside the furnace and meeting the vacuum environment requirements for quartz glass material production.

[0048] Finally, the pressure adjustment steps:

[0049] During the operation of the entire vacuum system, if the vacuum level inside the furnace fluctuates, the vacuum pressure regulating valve 331 can automatically adjust its opening based on the pressure signal fed back by the vacuum gauge 37. For example, when the vacuum level inside the furnace is higher than the set value, the vacuum pressure regulating valve 331 can be opened appropriately to allow some gas to flow back and stabilize the vacuum level; if the vacuum level is lower than the set value, the opening can be closed to work with the dry pump 31 and the diffusion pump 32 to increase the vacuum level, thereby achieving fine adjustment of the vacuum level and ensuring stable production. When the pressure inside the furnace rises abnormally due to special circumstances and exceeds the safety threshold, the electric exhaust valve 39 automatically opens to quickly discharge the gas inside the furnace, reduce the pressure, and play a safety protection role, preventing damage to the furnace body and affecting product quality due to excessive pressure.

[0050] As a further preferred embodiment, the gas source 46 is connected to the high-pressure inlet on / off valve 45 in sequence through ball valve 461, pressure regulating valve 413, low-pressure tank 41, pressure regulating valve ball valve 411, mass flow meter 43, and check valve 44; at the same time, the low-pressure tank 41 is connected in parallel to the high-pressure tank 42 through ball valve 414, booster 412, and high-pressure ball valve 421, and the high-pressure tank 42 is connected to the high-pressure inlet on / off valve 45 through high-pressure ball valve 422; pressure sensors 48 are provided at the inlet ends of the low-pressure tank 41, the high-pressure tank 42, and the furnace body assembly 1, and safety valves 47 are installed in parallel at the top of the low-pressure tank 41 and the high-pressure tank 42.

[0051] Low-pressure tank 41 is a 1m³ low-pressure tank, and high-pressure tank 42 is a 0.3m³ high-pressure tank.

[0052] Low-pressure intake mode:

[0053] Gas path connection: Gas source 46 sequentially passes through ball valve 461, pressure regulating valve 413, low-pressure tank 41, pressure regulating ball valve 411, mass flow meter 43, and check valve 44, connecting to high-pressure inlet on / off valve 45 to form a low-pressure inlet pipeline. At this time, due to the action of check valve 44, high-pressure backflow is prevented in the high-pressure inlet pipeline. The high-pressure pipeline is not pressurized at this time, and check valve 44 is in the state of opening the low-pressure gas path, allowing low-pressure gas to flow to furnace assembly 1.

[0054] Pressure regulation: Pressure regulating valve 413 can adjust the gas pressure entering the low-pressure tank 41, initially setting the low-pressure gas supply pressure range. Mass flow meter 43 accurately measures the low-pressure gas flow rate and adjusts the amount of gas entering the furnace assembly 1 according to production needs, ensuring a stable low-pressure environment inside the furnace. If the furnace pressure fluctuates due to gas input, the gas output can be adjusted by using a vacuum regulating valve in conjunction with a vacuum system and a dry pump to maintain pressure balance inside the furnace.

[0055] High-pressure intake mode:

[0056] Pressurization preparation: First, gas from low-pressure tank 41 is introduced into booster 412 via ball valve 2 414. Booster 412 operates, pressurizing the low-pressure gas to 2MPa, which is then stored in high-pressure tank 42 via high-pressure ball valve 1 421. During this process, the one-way valve 44 of the low-pressure intake line automatically closes due to the increased pressure on the high-pressure tank 42 side, preventing high-pressure gas from flowing back into the low-pressure line.

[0057] High-pressure gas supply: The gas in the high-pressure tank 42 enters the furnace body assembly 1 through the high-pressure ball valve 422 and the high-pressure gas inlet on / off valve 45, providing a high-pressure environment for the furnace and meeting the process requirements such as high-pressure densification in quartz glass production.

[0058] Pressure balancing and protection: Under high pressure, if the furnace pressure is too high, the electric exhaust valve will automatically open in conjunction with the vacuum system to release gas, regulate the pressure balance inside the furnace, and prevent excessive pressure from damaging the furnace body or affecting product quality.

[0059] The safety valve 47 at the top of the low-pressure tank 41 and the high-pressure tank 42 automatically opens to quickly release pressure when the pressure inside the tank is abnormally high.

[0060] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A high pressure vacuum electric smelting furnace, characterized in that It includes furnace body components, heating system components, vacuum system, pressurization system, stirring mechanism, and rotating mechanism; The furnace body assembly includes an upper furnace body, a lower furnace body, and a locking ring assembly, which seals the upper furnace body and the lower furnace body together. The thermal field assembly includes an upper insulation screen assembly, a middle insulation screen assembly, a lower insulation screen assembly, a main heater, a bottom heater, and a top heater. The upper and middle insulation screen assemblies are connected by fixing bolts and fixed to the upper furnace body by four sets of hanging rod bolts. The bottom of the middle insulation screen assembly is fixed to the inner wall of the upper furnace body by a thermal field fixing bracket. The lower insulation screen assembly is fixed to the insulation lifting assembly on the lower furnace body and moves with the insulation lifting assembly. The vacuum system includes a dry pump, a diffusion pump, a pre-evacuation valve, a high-pressure butterfly valve, a high-pressure valve, a fore-stage valve, a vacuum gauge, and a filter, used to create a vacuum environment inside the furnace. The pressurization system includes a low-pressure tank, a high-pressure tank, a mass flow meter, a check valve, a high-pressure inlet valve, and a gas source, used to regulate the pressure inside the furnace; The stirring component in the stirring mechanism can move up and down to stir the material. The rotating component in the rotating mechanism drives the crucible to rotate via a motor.

2. The high-pressure vacuum electrofusion melter according to claim 1, characterized in that The upper insulation screen assembly in the thermal field component includes alternating layers of tungsten and molybdenum upper insulation screens from the inside out. Each layer of tungsten and molybdenum upper insulation screens is separated by tungsten-molybdenum grid strips and fixed by tungsten-molybdenum bolt assemblies. The uppermost molybdenum upper insulation screen is sequentially equipped with an upper insulation ceramic insulation felt and an upper insulation welded frame. The middle insulation screen assembly includes alternating layers of tungsten and molybdenum middle insulation screens from the inside out. Each layer of tungsten and molybdenum middle insulation screens is separated by tungsten-molybdenum grid strips and fixed by tungsten-molybdenum bolt assemblies. The outermost molybdenum insulation screen is secured with bolts. A ceramic insulation felt and a welded frame are sequentially arranged around the outer side of the outermost molybdenum insulation screen. The lower insulation screen assembly includes alternating tungsten and molybdenum insulation screens from the inside out. Each layer of tungsten and molybdenum insulation screens is separated by tungsten-molybdenum grid strips and secured with bolts. A ceramic insulation felt and a welded frame are sequentially arranged at the lower end of the lowest molybdenum insulation screen. The upper and lower insulation screen assemblies contain electrode holes and thermocouple holes with boron nitride ceramic tubes.

3. The high-vacuum electric melting furnace according to claim 2, characterized in that, The thermal field assembly also includes a gas guide hood assembly, which includes a molybdenum gas guide pipe, a gas guide hood, and a molybdenum baffle plate. The molybdenum gas guide pipe and the gas guide hood are fastened together by gas guide hood fixing screws. The molybdenum baffle plate is disposed in the gap between the gas guide hood cover and the molybdenum gas guide pipe. The gas guide hood assembly is fastened to the upper insulation screen welding frame by gas guide cylinder fixing screws and gas guide cylinder fixing adapter plate.

4. The high pressure vacuum electro-fusion furnace of claim 1, wherein, The dry pump is connected in series with the pre-vacuum valve, diffusion pump, high-pressure valve, and high-pressure butterfly valve via a filter, ultimately forming a main vacuum pumping passage with the furnace assembly. The vacuum system also includes an electric exhaust valve and a vacuum pressure regulating valve. The electric exhaust valve is installed on the pipe section between the high-pressure butterfly valve and the furnace assembly. One end of the pre-vacuum valve is connected to the main vacuum passage between the furnace assembly and the high-pressure valve via a pipe, and the other end of the pre-vacuum valve is connected to the pipe between the pre-vacuum valve and the filter via a pipe. One end of the pre-vacuum valve is connected to the outlet of the diffusion pump, and the other end of the pre-vacuum valve is connected to the inlet of the filter. The vacuum pressure regulating valve is connected in parallel between the pipe connecting the pre-vacuum valve and the furnace assembly, and between the pipe connecting the pre-vacuum valve and the filter. One end of the vacuum pressure regulating valve is connected to the main passage between the furnace assembly and the high-pressure valve, and the other end of the vacuum pressure regulating valve is connected to the pipe between the pre-vacuum valve and the filter. The vacuum gauge is connected in series with the pressure monitoring branch of the furnace assembly via a vacuum gauge isolation valve.

5. The high pressure vacuum electro-fusion furnace of claim 1, wherein, The gas source is connected to the high-pressure inlet on / off valve in sequence through ball valve one, pressure regulating valve one, low-pressure tank, pressure regulating valve ball valve, mass flow meter, and check valve; at the same time, the low-pressure tank is connected to the high-pressure tank in parallel through ball valve two, booster, and high-pressure ball valve one, and the high-pressure tank is connected to the high-pressure inlet on / off valve through high-pressure ball valve two; pressure sensors are installed at the gas inlet ends of the low-pressure tank, high-pressure tank, and furnace body assembly, and safety valves are installed in parallel at the top of the low-pressure tank and high-pressure tank.

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