Stirring type tubular furnace

Abstract

The utility model relates to a stirring type tube furnace, and belongs to the technical field of metal smelting. The stirring type tubular furnace comprises a bracket, a heating furnace body, a quartz tube, a stirring device and a vertical lifting device, wherein the stirring device comprises a motor I for rotary driving, a stirring shaft and stirring blades; the vertical lifting device comprises a linear guide rail, a motor II, a ball screw and a sliding block which are vertically and fixedly arranged on the vertical supporting plate. The stirring device is used for stirring materials in the furnace, and the stirring device is rotated by utilizing a rotary driving motor; the vertical lifting device is matched with a sliding block, a linear guide rail and a ball screw, so that the stirring device ascends and descends in the vertical direction; the stirring type tubular furnace has the advantages of being compact in structure, uniform in stirring, stable in lifting, reliable in sealing and high in automation degree.

Description

Technical Field

[0001] This utility model relates to a stirred tube furnace, belonging to the field of metal smelting technology. Background Technology

[0002] Currently, traditional tube furnaces rely heavily on static heat conduction to melt materials, which easily leads to problems such as component segregation and grain coarsening. However, to significantly improve the strength and performance of materials, it is necessary to homogenize the melt composition to enhance solid-liquid mass transfer. However, the static melting process in existing tube furnaces cannot achieve melt agitation. While some tube furnaces with agitation functions exist, their complex structures, inconvenient operation, and difficulty in achieving precise control are significant challenges. Especially at high temperatures, the stability and sealing of the agitation device are difficult to guarantee, easily leading to equipment damage or safety hazards. Furthermore, existing tube furnaces often suffer from inaccurate positioning and unstable movement during material lifting and lowering, affecting the reliability of experimental results. Therefore, improvements to existing technologies are urgently needed to address these issues. Utility Model Content

[0003] The purpose of this application is to provide a stirred tube furnace, including a support frame, a heating furnace body, a quartz tube, a stirring device, and a vertical lifting device. The stirring device is used to stir the materials inside the furnace and is driven by a rotary motor to rotate. The vertical lifting device uses a slider, a linear guide rail, and a ball screw to lift the stirring device vertically. This stirred tube furnace has the advantages of compact structure, uniform stirring, stable lifting, reliable sealing, and high degree of automation.

[0004] The technical solution adopted by this utility model to solve its technical problem is:

[0005] A stirred tube furnace includes a support frame 4, a heating furnace body 13, a quartz tube 11, a stirring device, and a vertical lifting device.

[0006] The heating furnace body 13 is placed inside the bracket 4. A vertical support plate 5 is fixedly installed on the top of the bracket 4. The quartz tube 11 is vertically inserted into the center of the heating furnace body 13. The bottom end of the quartz tube 11 extends to the bottom end of the heating furnace body 13. A vacuum chamber is installed at the top end of the quartz tube 11. The vacuum chamber is connected to the vacuum pump 2. The outer side of one end of the vacuum chamber is fixedly connected to the bottom of the vertical support plate 5. A flange 8 is fixedly installed at the top end of the vacuum chamber. The flange 8 has a central through hole.

[0007] The stirring device includes a rotary-driven motor I6, a stirring shaft 12, and stirring blades. The output end of the motor I6 is fixedly connected to the top end of the stirring shaft 12. The stirring blades are fixedly installed at the bottom end of the stirring shaft 12. The bottom of the stirring shaft 12 passes through the central through hole of the flange 8 and extends into the quartz tube 11. A connecting bracket 7 is fixedly installed on the top of the stirring device.

[0008] The vertical lifting device includes a linear guide rail 17, a motor II 3, a ball screw 16, and a slider 18, which are vertically fixed on a vertical support plate 5. The top end of the ball screw 16 is connected to the output end of the motor II 3. The two ends of the slider 18 are end A and end B, respectively. End A of the slider 18 is fixedly connected to the connecting bracket 7, and end B of the slider 18 slides on the linear guide rail 17. A threaded hole is vertically opened in the center of the slider 18, and the ball screw 16 meshes with the threaded hole of the slider 18.

[0009] Preferably, the vertical lifting device further includes a coupling 14. The top and bottom ends of the linear guide rail 17 are respectively fixedly provided with a horizontal plate I and a horizontal plate II. The motor II3 is fixedly provided on the horizontal plate I. The output end of the motor II3 passes vertically downward through the horizontal plate I and is fixedly connected to the top end of the ball screw 16 through the coupling 14. The top of the ball screw 16 is provided with a limiter 15. A ball bearing is embedded in the center of the horizontal plate II. The bottom end of the ball screw 16 is inserted into the center ring of the ball bearing.

[0010] Preferably, the vacuum chamber is equipped with a vacuum pump valve 10 and a pressure gauge 9, and the vacuum pump valve 10 is externally connected to a vacuum pump 2 through a vacuum tube.

[0011] Preferably, the inner wall of the heating furnace body 13 is provided with a heat insulation shell 20, and a plurality of thermocouples 21 are evenly arranged on the inner side wall of the heat insulation shell 20. The cavity inside the heat insulation shell 20 is a heating cavity. A refractory brick 23 is arranged at the bottom center of the heating cavity. The refractory brick 23 is located inside the quartz tube 11. A crucible 22 is placed at the top of the refractory brick 23. The crucible 22 is filled with reaction raw materials. The bottom of the stirring shaft 12 extends into the crucible 22. A temperature sensor 19 is arranged inside the heating cavity.

[0012] Preferably, the stirred tube furnace further includes a controller 1, and motor I 6, vacuum pump 2, motor II 3, vacuum pump valve 10, pressure gauge 9, and temperature sensor 19 are all connected to the controller 1.

[0013] Preferably, a sealing ring is provided in the central through hole of the flange 8, and the stirring shaft 12 extends downward through the sealing ring in the central through hole.

[0014] Preferably, the stirring blades include stirring blade I and stirring blade II, which are respectively disposed on the two sides of the bottom end of the stirring shaft 12. The inclination angle of stirring blade I relative to the vertical plane is 10 to 30°, and the inclination angle of stirring blade II relative to the vertical plane is -10 to -30°.

[0015] Preferably, the B end of the slider 18 has a "[" shaped structure, which slides in conjunction with the convex structure of the linear guide rail 17.

[0016] Preferably, an inert gas tube is vertically inserted inside the quartz tube 11, the inert gas tube is connected to the outlet of the inert gas cylinder, the vacuum chamber is provided with an inert gas outlet, and the inert gas outlet is connected to the inlet of the inert gas cylinder through an inert gas connecting pipe.

[0017] The beneficial effects of this utility model are:

[0018] (1) The present invention is a stirring tube furnace, including a support, a heating furnace body, a quartz tube, a stirring device, and a vertical lifting device. The stirring device is used to stir the materials in the furnace and is driven by a rotary motor to rotate the stirring device. The vertical lifting device uses a slider, a linear guide rail, and a ball screw to lift the stirring device in the vertical direction.

[0019] (2) The stirring tube furnace of this utility model achieves uniform mixing of melt through stirring device, and the vertical lifting device ensures precise positioning of material. The vacuum chamber and sealing structure improve the stability of high temperature environment. It has the advantages of compact structure, uniform stirring, stable lifting, reliable sealing and high degree of automation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a stirred tubular furnace.

[0021] Figure 2 This is a schematic diagram of the stirring device.

[0022] Figure 3 This is a schematic diagram of the vertical lifting device.

[0023] Figure 4 This is a schematic diagram of the heating furnace body;

[0024] Figure 5 A schematic diagram of a stirred tube furnace containing a controller;

[0025] In the diagram, the components are: controller 1, vacuum pump 2, motor II 3, bracket 4, vertical support plate 5, motor I 6, connecting bracket 7, flange 8, pressure gauge 9, vacuum pump valve 10, quartz tube 11, stirring shaft 12, heating furnace body 13, coupling 14, limit switch 15, ball screw 16, linear guide rail 17, slider 18, temperature sensor 19, insulation shell 20, thermocouple 21, crucible 22, and refractory brick 23. Detailed Implementation

[0026] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] In existing technologies, traditional tube furnaces primarily rely on static heat conduction to melt materials, lacking a dynamic mixing mechanism in the high-temperature environment. Materials are prone to compositional segregation when left stagnant for extended periods, making it difficult to control grain growth direction and resulting in an inhomogeneous microstructure in the final product. For example, during alloy preparation, metallic elements with significant density differences are prone to stratification, severely impacting the material's mechanical properties.

[0028] To address the aforementioned issues and the inability of static melting to achieve uniform molten mixing, this study focuses on establishing a dynamic stirring mechanism. Based on the stability requirements of the mechanical structure under high-temperature conditions, a solution is proposed that integrate the stirring device and vertical lifting system into the main structure of the tube furnace. Sealing components solve the problem of sealing moving parts under high-temperature vacuum conditions, and a precision transmission system enables adjustable stirring depth, thus adapting to melt states of different viscosities.

[0029] like Figure 1-4 As shown, this application proposes a stirred tube furnace, including a support frame 4, a heating furnace body 13, a quartz tube 11, a stirring device, and a vertical lifting device.

[0030] The heating furnace body 13 is placed inside the bracket 4. A vertical support plate 5 is fixedly installed on the top of the bracket 4. The quartz tube 11 is vertically inserted into the center of the heating furnace body 13. The bottom end of the quartz tube 11 extends to the bottom end of the heating furnace body 13. A vacuum chamber is installed at the top end of the quartz tube 11. The vacuum chamber is connected to the vacuum pump 2. The outer side of one end of the vacuum chamber is fixedly connected to the bottom of the vertical support plate 5. A flange 8 is fixedly installed at the top end of the vacuum chamber. The flange 8 has a central through hole.

[0031] The stirring device includes a rotary-driven motor I6, a stirring shaft 12, and stirring blades. The output end of the motor I6 is fixedly connected to the top end of the stirring shaft 12. The stirring blades are fixedly installed at the bottom end of the stirring shaft 12. The bottom of the stirring shaft 12 passes through the central through hole of the flange 8 and extends into the quartz tube 11. A connecting bracket 7 is fixedly installed on the top of the stirring device.

[0032] The vertical lifting device includes a linear guide rail 17, a motor II 3, a ball screw 16, and a slider 18, which are vertically fixed on a vertical support plate 5. The top end of the ball screw 16 is connected to the output end of the motor II 3. The two ends of the slider 18 are end A and end B, respectively. End A of the slider 18 is fixedly connected to the connecting bracket 7, and end B of the slider 18 slides on the linear guide rail 17. A threaded hole is vertically opened in the center of the slider 18, and the ball screw 16 meshes with the threaded hole of the slider 18.

[0033] Preferably, the B end of the slider 18 has a "[" shaped structure, which slides in conjunction with the convex structure of the linear guide rail 17.

[0034] The quartz tube is vertically positioned so that its axis is parallel to the direction of gravity. It can be made of high-purity fused quartz material, capable of withstanding high temperatures and maintaining chemical inertness. The vacuum chamber is a sealed space connected to the top of the quartz tube. It can be welded to a flange to ensure airtightness in high-temperature environments. The flange center through-hole is a circular hole penetrating the flange thickness, which can be fitted with a graphite sealing ring to achieve dynamic sealing of the rotating shaft. The engagement of the ball screw and slider converts rotational motion into linear displacement through a precision threaded pair; pre-tightened ball nuts can be used to eliminate transmission backlash. The vertically fixed linear guide rail ensures that its axis is parallel to the axis of the quartz tube; crossed roller guide rails can be used to ensure the accuracy of the lifting trajectory.

[0035] Specifically, the heating furnace body maintains a stable heating state inside the support frame, and the quartz tube is vertically inserted so that its heated area covers the material reaction zone. A vacuum pump maintains an inert environment inside the quartz tube through a vacuum chamber to prevent material oxidation. A motor drives the stirring shaft, rotating the blades and directly acting on the melt in the crucible to achieve forced convection. A vertical lifting device precisely adjusts the immersion depth of the stirring blades in the melt by controlling the rotation angle of the ball screw. Linear guide rails constrain the movement trajectory of the slider, ensuring that the stirring shaft always coincides with the axis of the quartz tube, avoiding lateral displacement that could lead to seal failure or tube wall collision.

[0036] Compared to existing technologies, traditional tube furnaces only achieve material melting through heat conduction and lack active mixing capabilities. This solution, while maintaining high-temperature processing capacity, adds an adjustable dynamic stirring mechanism. By combining mechanical transmission and sealing technology, the stability of moving parts in high-temperature vacuum environments is resolved. The vertical lifting system allows for real-time adjustment of the stirring depth based on melt viscosity, significantly improving process adaptability compared to fixed stirrers. This application achieves active mixing of the melt at high temperatures, effectively eliminating component segregation caused by density differences. Dynamic stirring promotes mass transfer at the solid-liquid interface, inhibits abnormal grain growth, and yields a uniform and dense microstructure. Precise lifting control matches the stirring intensity to the material state, avoiding energy waste or equipment damage caused by over-stirring, providing a reliable guarantee for the preparation of high-performance materials.

[0037] This scheme increases the effective electrolysis area by multiple times within the same volume through a vertically arranged, multi-layered alternating arrangement of anode and cathode electrodes. Traditional devices often use a side-to-center inlet, which can easily create flow dead zones. This scheme's vertical convection design ensures uniform liquid flow through all electrode layers. This application achieves highly efficient electrochemical degradation of organic matter in wastewater. The multi-layered electrode layout extends the residence time of pollutants in the electric field, enhancing the electrolytic degradation reaction. The sealed structure effectively prevents the leakage of harmful gases, reducing environmental risks. The sliding electrode design simplifies maintenance and improves the continuity of equipment operation. The vertical convection liquid distribution avoids electrode passivation caused by excessively high local concentrations, ensuring the stability of treatment efficiency.

[0038] This application further proposes that the vertical lifting device also includes a coupling 14, and a horizontal plate I and a horizontal plate II are fixedly installed at the top and bottom of the linear guide rail 17, respectively. The motor II3 is fixedly installed on the horizontal plate I, and the output end of the motor II3 passes vertically downward through the horizontal plate I and is fixedly connected to the top of the ball screw 16 through the coupling 14. A limiter 15 is provided at the top of the ball screw 16, and a ball bearing is embedded in the center of the horizontal plate II. The bottom end of the ball screw 16 is inserted into the center ring of the ball bearing.

[0039] The coupling refers to the transmission component used to connect the motor output shaft and the ball screw. It can be implemented using a flexible coupling or a universal coupling, compensating for axial and angular misalignment through a flexible connection. Horizontal plates I and II refer to the horizontal support structures fixed at both ends of the linear guide rail. They can be implemented using welded steel plates or bolted aluminum profile frames, forming a rigid mounting base to support the motor and bearings. The limit switch is a mechanical blocking device installed at the top of the ball screw. It can be implemented using threaded limit nuts or photoelectric sensors, used to limit the upward stroke of the slider to prevent collisions. The ball bearing is a rotating support component installed at the center of horizontal plate II. It can be implemented using deep groove ball bearings or angular contact bearings, supporting the rotation of the screw and constraining radial displacement through rolling friction.

[0040] Specifically, the motor output shaft forms a flexible transmission with the top of the ball screw through a coupling, allowing for coaxiality deviations during installation; Horizontal plate I provides a fixed reference surface for the motor, and horizontal plate II forms a rotational support for the bottom of the screw through ball bearings; a limiter forms a mechanical block at the top of the screw, triggering limit protection when the slider rises to the set position; when the ball screw rotates, the inner ring of the bearing rotates synchronously with the screw, and the outer ring is fixed on horizontal plate II, forming a stable rotational support structure.

[0041] Compared to existing technologies, traditional vertical lifting devices often use a direct rigid connection between the motor and the lead screw, which is prone to deformation of transmission components due to assembly errors. The bottom of the lead screw is usually suspended or supported only by a simple sliding bearing, resulting in large radial runout and poor positioning accuracy. This solution compensates for installation deviations through a flexible connection using a coupling, and the double-horizontal-plate structure forms a closed frame. Combined with the precision support of ball bearings, this provides the lead screw with dual positioning constraints. This application effectively solves the vibration problem caused by unstable motor-lead screw connection, eliminates radial runout during lead screw rotation, reduces transmission losses due to the low friction characteristics of the ball bearings, and ensures precise control of the lifting stroke through the use of limiters and couplings. The overall structure significantly improves the motion accuracy and service life of the lifting device.

[0042] This application further proposes that the vacuum chamber is equipped with a vacuum pump valve 10 and a pressure gauge 9, and the vacuum pump valve 10 is externally connected to a vacuum pump 2 through a vacuum tube.

[0043] The vacuum pump valve is a device used to control the direction of gas flow. It can be implemented using a solenoid valve or a manual shut-off valve. Its function is to open the pipeline during vacuuming to allow gas to escape, and to adjust the opening degree to balance the pressure difference between the inside and outside of the vacuum while maintaining the vacuum level. The pressure gauge is a device used to detect the gas pressure inside the chamber. It can be implemented using a mechanical pressure gauge or a digital sensor. Its function is to provide data feedback for starting and stopping the vacuum pump and adjusting the valve opening by monitoring the real-time pressure changes in the vacuum chamber. The vacuum tube is the pipe connecting the vacuum chamber and the vacuum pump. It can be implemented using a stainless steel corrugated pipe or a high-temperature resistant silicone tube. Its function is to form a gas transmission channel through a sealed connection, ensuring directional gas flow during vacuuming.

[0044] Specifically, the pressure gauge is directly integrated into the outer wall of the vacuum chamber, collecting real-time gas pressure data and converting it into an electrical signal that is transmitted to the control system. When the gas pressure inside the vacuum chamber exceeds a set threshold, the control system drives the vacuum pump valve to open and close based on the pressure gauge feedback signal. When a negative pressure environment needs to be established, the vacuum pump valve is fully open, and the vacuum pump quickly extracts gas from the chamber through the vacuum tube; when the gas pressure reaches the target value, the valve opening automatically decreases to maintain a constant vacuum. Through the linkage control of the pressure gauge and the valve, a closed-loop control mechanism is formed, ensuring that volatile gases generated during melt stirring can be discharged in a timely manner, while avoiding drastic fluctuations in the melt surface due to excessive pumping. For example, in the high-temperature molten state, bubbles generated on the melt surface are adsorbed into the vacuum tube due to the negative pressure, and the pressure gauge detects the gas pressure fluctuation in real time and triggers the valve to fine-tune the opening, ensuring that impurity gases are effectively discharged while maintaining the dynamic balance between the melt and the vacuum environment.

[0045] Compared to existing technologies, traditional tube furnaces rely solely on a single vacuum pump for unidirectional gas extraction, making it impossible to adjust the extraction rate and chamber pressure in real time. This leads to susceptibility to melt splashing or gas residue during melt stirring due to sudden pressure changes. This solution, however, utilizes a closed-loop control system with a pressure gauge and vacuum pump valves to dynamically adjust the vacuum level based on the melt state. This avoids melt composition loss due to excessive extraction and eliminates grain coarsening defects caused by gas residue. Furthermore, the vacuum pump is physically isolated from the high-temperature reaction zone via external piping, preventing thermal damage to the pump seals and extending the equipment's lifespan. This application achieves real-time monitoring and precise control of the vacuum environment during melt stirring, effectively preventing melt oxidation and compositional segregation caused by external gas infiltration. The synergistic effect of the pressure gauge and vacuum pump valves ensures efficient removal of bubbles from the melt surface while maintaining a stable negative pressure environment, achieving a dynamic balance between the gas diffusion rate and vacuum extraction rate within the melt. The external vacuum pump layout not only ensures the long-term operational reliability of the vacuum system, but also avoids the carbonization damage to the vacuum pump sealing material caused by high temperatures, thereby significantly improving the airtightness stability and process repeatability of the melt stirring process.

[0046] This application further proposes that the inner wall of the heating furnace body 13 is provided with a heat insulation shell 20, and a plurality of thermocouples 21 are evenly arranged on the inner side wall of the heat insulation shell 20. The cavity inside the heat insulation shell 20 is a heating cavity. A refractory brick 23 is arranged at the bottom center of the heating cavity. The refractory brick 23 is located inside the quartz tube 11. A crucible 22 is placed at the top of the refractory brick 23. The crucible 22 is filled with reaction raw materials. The bottom of the stirring shaft 12 extends into the crucible 22. A temperature sensor 19 is arranged inside the heating cavity.

[0047] The insulation shell refers to the heat-insulating structure wrapped around the inside of the heating furnace, which can be constructed from layers of ceramic fiber or aluminosilicate. It maintains a stable temperature field within the furnace by blocking heat conduction outwards. Thermocouples are temperature-sensing elements distributed circumferentially along the inner wall of the insulation shell, such as K-type or S-type thermocouple arrays, used to collect real-time temperature gradient data from different areas of the heating cavity. Refractory bricks are high-temperature supports placed at the bottom of the heating cavity, made of materials such as alumina or silicon carbide. They physically isolate the quartz tube from the high-temperature crucible, preventing deformation of the quartz tube due to direct heating. Temperature sensors are monitoring devices embedded inside the heating cavity, such as platinum resistance thermometers or infrared temperature measurement modules, used to acquire overall temperature data of the heating cavity.

[0048] Specifically, the insulation shell forms a sealed heat insulation layer by wrapping around the inner wall of the heating furnace, controlling heat loss within a preset range. An array of thermocouples evenly distributed along the inner side of the insulation shell continuously monitors the temperature distribution in the heating area. When a localized temperature anomaly is detected, the heating power can be adjusted to restore a uniform temperature distribution. Refractory bricks are arranged inside the quartz tube and support the crucible, bearing the load of the high-temperature melt while preventing direct heat conduction to the quartz tube wall. The end of the stirring shaft extends into the crucible, creating forced convection in the melt through rotation, enabling dynamic mixing of the reactants. Temperature sensors and thermocouples complement each other, jointly constructing a closed-loop temperature control system for the heating chamber.

[0049] Compared to existing technologies, traditional tube furnaces rely on static heating, resulting in low melt mixing efficiency. This solution, however, utilizes a crucible supported by refractory bricks at the bottom of the heating chamber, coupled with a stirring shaft extending into the melt, enabling forced convection mixing of materials even in a high-temperature molten state. Existing technologies lack real-time monitoring of the temperature gradient in the heating zone, while this solution achieves precise control of the temperature distribution within the heating chamber through the coordinated operation of a uniformly distributed thermocouple array and temperature sensors. This application solves the problem of component segregation caused by static heat conduction in the melt, achieving dynamic mixing through mechanical stirring; it overcomes the grain coarsening defects caused by uneven temperature fields in traditional tube furnaces by constructing a precise temperature control system using multi-dimensional temperature monitoring; and the combined structure of refractory bricks and quartz tubes protects the quartz tube from thermal damage while achieving high-temperature reactions.

[0050] like Figure 5 As shown, this application further proposes the stirred tube furnace, which also includes a controller 1, a motor I 6, a vacuum pump 2, a motor II 3, a vacuum pump valve 10, a pressure gauge 9, and a temperature sensor 19, all of which are connected to the controller 1.

[0051] The system comprises the following components: Controller: A central control unit that coordinates the equipment's operational logic, implemented using a programmable logic controller (PLC) or embedded microprocessor. It transmits instructions to the execution components via preset programs or real-time signal input / output. Motor I: The electric motor that drives the stirring shaft. It can be a stepper motor or servo motor, controlling the mixing effect of the stirring blades by adjusting the speed and direction. Vacuum Pump: A device that maintains a negative pressure environment in the vacuum chamber. It can be a rotary vane vacuum pump or a molecular pump, adjusting the chamber pressure through opening and closing operations. Motor II: The electric motor that drives the ball screw. It can be a servo motor with an encoder, precisely controlling the number of rotations to achieve millimeter-level adjustment of the slider's lifting position. Vacuum Pump Valve: A solenoid valve that controls the opening and closing of the vacuum pipeline. It can be a normally closed solenoid valve, triggering the connection or isolation between the vacuum pump and the chamber via an electrical signal. Pressure Gauge: A sensor that monitors the pressure in the vacuum chamber. It can be a piezoresistive or capacitive vacuum gauge, providing real-time pressure feedback from the chamber via analog signals. A temperature sensor is a device that detects the temperature of a heating cavity. Specifically, it can be implemented using a K-type thermocouple or an infrared temperature measurement module, and transmits temperature data through digital signals.

[0052] Specifically, the controller receives vacuum data detected by the pressure gauge. When the pressure exceeds a set threshold, it automatically starts the vacuum pump and opens the vacuum pump valve to bring the cavity to the target vacuum environment. Simultaneously, the controller adjusts the heating furnace power based on real-time temperature data from the temperature sensor, forming a closed-loop temperature control system. Motor I drives the stirring shaft to rotate via a speed curve preset by the controller, creating forced convection in the melt within the crucible. When the material quantity changes, the controller sends a pulse signal to Motor II, driving the ball screw to raise and lower the slider and stirring device as a whole, ensuring the stirring blades remain below the melt surface. The operating status of each execution unit is synchronized and logically interlocked through the controller, preventing response delays or parameter mismatches caused by manual operation.

[0053] Compared to existing technologies, traditional tube furnaces rely on manual operation of the vacuum pump, manual adjustment of the stirring height, and visual estimation of temperature, resulting in low control precision and slow response. This solution integrates the dispersed execution units within the equipment through a controller, automating and coordinating vacuum maintenance, temperature regulation, stirring speed, and height control. This eliminates human error and ensures stable environmental parameters during the melting process. This application achieves automated control of dynamic melt stirring and equipment operation, solving the problem of component segregation caused by static melting. The vacuum pump automatically starts and stops based on pressure feedback, maintaining a stable reaction environment; the stirring shaft height automatically adjusts with the material quantity, preventing stirring failure due to liquid level fluctuations; the temperature sensor and heating system form a closed-loop control, reducing temperature overshoot or undershoot. All components communicate and operate collaboratively through the controller, significantly improving melting uniformity and process stability.

[0054] This application further proposes that a sealing ring is provided in the central through hole of the flange 8, and the stirring shaft 12 extends downward through the sealing ring in the central through hole.

[0055] The sealing ring is an annular sealing element with elastic deformation capability, specifically made of fluororubber or silicone, which maintains its sealing performance even at high temperatures. This element is installed on the inner wall of the flange's central through-hole via an interference fit, with its inner diameter slightly smaller than the outer diameter of the agitator shaft to achieve radial compression contact. "Extending downwards through the sealing ring" means that the agitator shaft penetrates the center of the sealing ring vertically, forming a dynamic contact interface between the shaft and the inner wall of the sealing ring. This interface allows the agitator shaft to maintain a sealed state during rotation and axial movement.

[0056] Specifically, when the stirring shaft rotates or moves up and down driven by the vertical lifting device, the inner wall of the sealing ring and the surface of the stirring shaft are always in elastic contact. During axial movement, the sealing ring compensates for mechanical clearance through its own elastic deformation, preventing leakage channels due to position changes; during rotational movement, the inner wall of the sealing ring and the surface of the stirring shaft form a sliding seal, blocking the gas exchange path between the vacuum chamber and the external environment. This dynamic sealing structure allows the vacuum pump to maintain only the initial vacuum operation without continuous operation to compensate for leakage.

[0057] Compared with existing technologies, traditional static sealing structures cannot meet the requirements of the complex motion of the stirring shaft. They often employ multi-layer packing seals or complex magnetohydrodynamic (MHD) sealing devices, resulting in high maintenance costs and bulky structures. This solution achieves sealing under complex motion using a single elastic sealing ring, simplifying the sealing structure and eliminating the need for an external cooling system required by MHD seals, thus reducing equipment manufacturing costs. This application effectively solves the problem of gas leakage in the vacuum chamber during the stirring shaft's movement, ensuring uniform stirring of the high-temperature melt inside the quartz tube in an oxygen-free environment, preventing material oxidation caused by external air infiltration, and reducing the energy consumption of the vacuum pump.

[0058] This application further proposes that the stirring blades include stirring blade I and stirring blade II, which are respectively disposed on the corresponding sides of the bottom end of the stirring shaft 12. The inclination angle of stirring blade I relative to the vertical plane is 10 to 30°, and the inclination angle of stirring blade II relative to the vertical plane is -10 to -30°.

[0059] The tilt angle of stirring blade I is 10–30°, meaning the blade plane forms a positive angle with the vertical direction. Specifically, the blade can be installed on one side of the stirring shaft by welding or bolting. This angle range causes the blade to generate downward axial flow during rotation. The tilt angle of stirring blade II is -10–30°, meaning the blade plane forms a negative angle with the vertical direction. This angle range causes the blade to generate upward backflow during rotation. The symmetrical arrangement of the blades on both sides can counteract vibrations caused by unilateral forces, and the bidirectional angle coordination enhances the three-dimensional mixing effect of the melt.

[0060] Specifically, when the stirring shaft rotates, stirring blade I pushes the melt downwards at a forward tilt angle, while stirring blade II guides the melt upwards backflow at a reverse tilt angle. These two opposing flows form a circulating vortex within the confined space of the quartz tube, enhancing longitudinal convection and transverse shearing. If the forward tilt angle is below 10°, insufficient axial thrust leads to reduced mixing efficiency; if it exceeds 30°, bubble entrainment is likely. Controlling the reverse tilt angle within the range of -10° to -30° ensures effective backflow while avoiding excessive energy loss. Through a symmetrical blade layout, the melt circulates longitudinally while simultaneously diffusing laterally, ensuring thorough mixing of high-viscosity raw materials.

[0061] Compared to existing technologies, traditional tube furnaces often employ single planar blades or unidirectional inclined blades, resulting in only unidirectional flow and incomplete melt mixing. This solution, however, uses a combination of blades with positive and negative inclination angles to create a forced vortex within a limited space, solving the compositional segregation problem caused by the unidirectional flow in traditional equipment. Compared to unidirectional blade structures, bidirectional blades generate a more uniform shear force distribution, effectively refining grains and suppressing deposition. This application enables three-dimensional mixing of the melt through both longitudinal circulation and lateral diffusion, eliminating compositional differences between the edge and center regions of the quartz tube and suppressing abnormal grain growth. While ensuring stirring efficiency, this structure reduces vibration risk through a symmetrical layout, making it suitable for long-term continuous stirring of high-viscosity melts.

[0062] This application further proposes that an inert gas tube is vertically inserted inside the quartz tube 11, the inert gas tube is connected to the outlet of the inert gas cylinder, the vacuum chamber is provided with an inert gas outlet, and the inert gas outlet is connected to the inlet of the inert gas cylinder through an inert gas connecting pipe.

[0063] The inert gas tube is a pipe used to transport inert gas into the quartz tube. It can be made of high-temperature resistant and airtight stainless steel. By connecting to the outlet of the inert gas cylinder, the inert gas can be continuously injected into the quartz tube, thereby isolating the oxidation effect of oxygen on the reaction raw materials.

[0064] The inert gas outlet refers to the gas outlet set on the vacuum chamber. Specifically, it can be implemented using an interface structure with a flow regulating valve. A closed loop is formed between the inert gas connecting pipe and the inert gas cylinder, allowing the inert gas to circulate between the quartz tube and the cylinder, thus avoiding the waste caused by the inert gas being directly discharged into the external environment.

[0065] Specifically, inert gas is transported from the gas cylinder to the bottom of the quartz tube through an inert gas tube. After being fully contacted with the reaction raw materials by the stirring device, it carries volatiles or impurities into the vacuum chamber, and then returns to the gas cylinder inlet through the inert gas outlet and connecting pipe. This cycle can create an inert environment inside the tube furnace and simultaneously achieve gas reuse.

[0066] Compared to existing technologies, traditional tubular furnaces typically employ an open inert gas supply system, relying solely on unidirectional ventilation to replace the air inside the furnace. This approach cannot prevent external air infiltration or inert gas escape, leading to an unstable reaction environment. This solution, through a closed-loop design, maintains a constant inert environment within the furnace while reducing inert gas consumption. This application continuously isolates oxygen from the reactants during the smelting process, preventing oxidation reactions. Simultaneously, the inert gas circulation effectively removes volatile impurities, improving the purity of the reaction products and reducing the frequency and cost of inert gas replenishment.

[0067] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A stirred tube furnace characterized by: The device comprises a support (4), a heating furnace body (13), a quartz tube (11), a stirring device, a vertical lifting device, The heating furnace body (13) is placed in the support (4), and a vertical support plate (5) is fixedly arranged on the top of the support (4). The quartz tube (11) is vertically and downwardly inserted into the center of the heating furnace body (13), and the bottom end of the quartz tube (11) extends to the bottom end of the heating furnace body (13). The top end of the quartz tube (11) is provided with a vacuum cavity, which is communicated with the vacuum pump (2). The outer side surface of one end of the vacuum cavity is fixedly connected with the bottom of the vertical support plate (5), and a flange (8) is fixedly arranged on the top end of the vacuum cavity. The flange (8) is provided with a central through hole. The stirring device comprises a rotationally driven motor I (6), a stirring shaft (12) and stirring blades. The output end of the motor I (6) is fixedly connected with the top end of the stirring shaft (12), and the stirring blades are fixedly arranged on the bottom end of the stirring shaft (12). The bottom of the stirring shaft (12) penetrates through the central through hole of the flange (8) and extends into the quartz tube (11). The top of the stirring device is fixedly provided with a connecting support (7). The vertical lifting device comprises a linear guide rail (17) which is vertically and fixedly arranged on the vertical support plate (5), a motor II (3), a ball screw (16) and a sliding block (18). The top end of the ball screw (16) is connected with the output end of the motor II (3). The sliding block (18) has two ends, which are respectively an A end and a B end. The A end of the sliding block (18) is fixedly connected with the connecting support (7), and the B end of the sliding block (18) is slidably arranged on the linear guide rail (17). A threaded hole is vertically arranged in the center of the sliding block (18), and the ball screw (16) is engaged with the threaded hole of the sliding block (18).

2. The stirred tube furnace of claim 1, wherein: The vertical lifting device further comprises a coupling (14). The top end and the bottom end of the linear guide rail (17) are respectively fixedly provided with a horizontal plate I and a horizontal plate II. The motor II (3) is fixedly arranged on the horizontal plate I. The output end of the motor II (3) penetrates through the horizontal plate I vertically downwardly and is fixedly connected with the top end of the ball screw (16) through the coupling (14). The top of the ball screw (16) is provided with a limit stop (15). A ball bearing is embedded in the center of the horizontal plate II, and the bottom end of the ball screw (16) is inserted into the center ring of the ball bearing.

3. The stirred tube furnace of claim 1, wherein: The vacuum cavity is provided with a vacuum pump valve (10) and a pressure gauge (9). The vacuum pump valve (10) is connected with the vacuum pump (2) through a vacuum pipe.

4. The stirred tube furnace according to claim 1 or 3, characterized in that: The inner wall of the heating furnace body (13) is provided with a heat preservation shell (20). A plurality of thermocouples (21) are uniformly arranged on the inner side wall of the heat preservation shell (20). The cavity in the heat preservation shell (20) is a heating cavity. A refractory brick (23) is arranged at the bottom center of the heating cavity. The refractory brick (23) is located in the quartz tube (11). A crucible (22) is arranged on the top end of the refractory brick (23). The crucible (22) is filled with reaction raw materials. The bottom of the stirring shaft (12) extends into the crucible (22). A temperature sensor (19) is arranged in the heating cavity.

5. The stirred tube furnace of claim 1, wherein: A controller (1) is further arranged. The motor I (6), the vacuum pump (2) and the motor II (3) are connected with the controller (1).

6. The stirred tube furnace of claim 1, wherein: A sealing ring is arranged in the central through hole of the flange (8), and the stirring shaft (12) extends downward through the sealing ring in the central through hole.

7. The stirred tube furnace of claim 1, wherein: The stirring blades include stirring blade I and stirring blade II, which are arranged on the two sides of the bottom end of the stirring shaft (12) respectively, the inclination angle of the stirring blade I relative to the vertical plane is 10-30°, and the inclination angle of the stirring blade II relative to the vertical plane is-10--30°.

8. The stirred tube furnace of claim 1, wherein: The B end of the sliding block (18) is of a "[ " type structure, which cooperates with the convex type structure of the linear guide rail (17) to slide.

9. The stirred tube furnace of claim 1, wherein: An inert gas pipe is vertically inserted into the quartz tube (11), the inert gas pipe is connected with the gas outlet end of an inert gas cylinder, the vacuum cavity is provided with an inert gas outlet, and the inert gas outlet is connected with the gas inlet end of the inert gas cylinder through an inert gas connecting pipe.

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