High-strength glass tube annealing equipment and annealing method
By using an annular furnace and an inner wall temperature control component in the glass tube annealing equipment, the power of the heating wire can be adjusted in real time, thus solving the problem of temperature difference between the inner and outer walls of the glass tube and improving the processing quality and service life of the glass tube.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG AHUA PACKAGE PRINTING
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-12
AI Technical Summary
In existing glass annealing equipment, there is a temperature difference between the inner and outer walls of the glass tube, which leads to radial stress and affects processing quality and service life.
The system employs a ring-shaped furnace body, a revolution mechanism, an inner wall temperature control component, and a control and adjustment component. The inner wall of the glass tube is heated, kept warm, and cooled by a mandrel. Temperature sensors and controllers are used to adjust the heating power of the heating wire in real time to ensure that the temperature difference between the inner and outer walls is within a reasonable range.
This technology enables synchronous temperature changes on the inner and outer walls of the glass tube, eliminating radial stress and improving processing quality and service life.
Smart Images
Figure CN122010398A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of glass annealing technology, and in particular to a high-strength glass tube annealing device and annealing method. Background Technology
[0002] Annealing is a key heat treatment process in glass manufacturing, mainly divided into heating, holding, and cooling stages. Existing glass annealing equipment, such as tunnel annealing furnaces, generally only regulates the temperature of the outer wall of the glass tube through heating elements, insulation layers, or cooling mechanisms on the inner wall of the furnace. Furthermore, the glass tube is transported in a straight line along its length, resulting in uneven heating and cooling across different parts of the tube. Simultaneously, the heat exchange efficiency of the inner wall is much lower than that of the outer wall. During the heating stage, the outer wall rapidly heats up to the annealing temperature due to furnace heating, while the inner wall, due to air insulation, takes a longer time to reach a similar temperature, creating a temperature difference of 20-35°C. During the holding stage, the outer wall maintains a stable temperature through compensating heating, while the inner wall, due to slower heat dissipation, tends to be 10-20°C higher than the outer wall. During the cooling stage, the outer wall is rapidly cooled by cold air curtains or water-cooled jackets, while the inner wall cannot dissipate heat in a timely manner. This persistent temperature difference between the inner and outer walls can easily lead to radial stress inside the glass tube, causing cracks and damage during subsequent cutting, processing, or use, thus affecting the product's qualification rate and service life.
[0003] Based on the above, we propose a high-strength glass tube annealing equipment and annealing method to solve the above problems. Summary of the Invention
[0004] This invention provides a high-strength glass tube annealing equipment and annealing method to solve the problem in the prior art where the temperature difference between the inner and outer walls during glass tube annealing affects the quality of subsequent processing.
[0005] The technical problem solved by this invention is achieved by the following technical solution: A high-strength glass tube annealing device includes an annular furnace body, a revolving mechanism, an inner wall temperature control component, and a control and adjustment component. The annular furnace body is divided circumferentially by partitions into a heating zone, a heat preservation zone, a cooling zone, and a loading / unloading zone. The loading / unloading zone is an open section of the annular furnace body used for loading glass tubes to be annealed and unloading glass tubes after annealing. The revolving mechanism is rotatable along the axis of the annular furnace body and includes a self-rotating mechanism connected to it, with a support frame for holding the glass tubes. The inner wall temperature control component includes a core rod corresponding to each glass tube. The mandrel is pluggably adapted to the hollow cavity of the glass tube along the axial direction of the glass tube to be annealed via a lifting mechanism. It is used to heat, maintain, and cool the inner wall of the glass tube. The control and adjustment component includes a first temperature sensor on the mandrel, an electric heating wire inside the displacement mandrel, a second temperature sensor inside the annular furnace, and a controller electrically connected to the first and second temperature sensors. The controller is used to receive the temperature signals from the first and second temperature sensors, compare the temperature difference between the inner and outer walls of the glass tube, and control the heating power of the electric heating wire to change when the temperature difference exceeds a set threshold.
[0006] Preferably, the revolution mechanism includes a first drive motor and a first rotating shaft connected to the output end of the first drive motor, and the first rotating shaft is provided with a supporting turntable that is rotatably connected to the annular furnace body.
[0007] Preferably, the self-rotating mechanism includes a second drive motor connected to the supporting turntable and a second rotating shaft connected to the output end of the second drive motor, and the support frame is fixedly connected to the second rotating shaft and coaxially arranged with the second rotating shaft.
[0008] Preferably, the lifting mechanism includes a telescopic component installed in the second rotating shaft and a lifting plate connected to the movable end of the telescopic component. The lifting plate is slidably connected to the second rotating shaft, and the mandrel is connected to the lifting plate.
[0009] Preferably, the mandrel is further provided with an air blowing pipe, the input end of which is rotatably connected to a first air pipe, the input end of which is connected to a main air pipe rotatably connected to the annular furnace body, and the main air pipe is connected to an external air source.
[0010] Preferably, a position sensor is provided in the cooling zone, a control valve is provided on the first air pipe, and the controller is further configured to control the control valve in the corresponding cooling zone to open and blow air after receiving a signal from the position sensor.
[0011] Preferably, the bottom opening end of the air blowing pipe is provided with a tapered guide section with the tip pointing upwards.
[0012] Preferably, the core rod is made of high-temperature resistant ceramic, and the outer diameter of the core rod is 1 / 3 to 1 / 2 of the inner diameter of the glass tube to be annealed.
[0013] An annealing method for a high-strength glass tube annealing apparatus, based on the aforementioned high-strength glass tube annealing apparatus, includes the following steps: S1. Loading and mandrel fitting: Place the glass tubes to be annealed one by one on the support frame, and drive the lifting plate through the lifting mechanism to insert the mandrel along the axial direction of the glass tube. S2. The revolution and rotation start synchronously: the first drive motor drives the supporting turntable to rotate along the axis of the annular furnace body, so that the support frame revolves with the supporting turntable. At the same time, the second drive motor drives the second rotating shaft and the support frame to rotate around their own axis. The glass tube rotates synchronously with the support frame to achieve uniform heating. S3. Adjustment of temperature difference between inner and outer walls of glass tube: Based on the temperature value of the inner wall of glass tube fed back by the first temperature sensor and the temperature inside the annular furnace body fed back by the second temperature sensor, the controller finely adjusts the power of the heating wire in real time to ensure that the temperature difference between the inner and outer walls is always within the set threshold. S4. Unloading and Resetting: When the glass tube has finished cooling and has rotated with the support turntable to the loading and unloading area, the controller closes the corresponding control valve and starts the lifting mechanism to drive the mandrel to be slowly pulled out of the glass tube; the operator removes the annealed glass tube from the support frame and places the new glass tube to be annealed in place to enter the next annealing cycle.
[0014] The beneficial effects of this invention are: The mandrel can be inserted into the glass tube to detect the temperature of the inner wall of the glass tube. It forms a data linkage with the second temperature sensor on the outer wall of the ring furnace. The controller dynamically adjusts the heating power of the heating wire built into the mandrel by comparing the temperature difference between the two. This eliminates the problem of abnormal temperature difference between the inner and outer walls caused by the existing equipment relying solely on the outer wall for temperature control, and avoids radial stress residue caused by the temperature difference between the inner and outer walls of the glass tube. By combining revolution and rotation, the glass tube can be evenly contacted by the heating, heat preservation, or cooling environment of all areas of the furnace body, avoiding the problem of local overheating or insufficient cooling of the outer wall of the glass tube caused by slight differences in the local temperature field of the furnace body; at the same time, the rotation combined with the mandrel to control the temperature of the inner wall allows the temperature of each point on the inner and outer walls of the glass tube to change synchronously, further reducing the stress superposition in the radial and circumferential directions. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of the isometric structure provided by the present invention; Figure 2 A schematic diagram of the internal structure of the annular furnace body provided by the present invention; Figure 3 A schematic diagram of the mounting structure of the first drive motor and the second drive motor provided for the present invention; Figure 4 This invention provides a cross-sectional structural schematic diagram; Figure 5 This is a schematic diagram of the lifting mechanism in this invention; Figure 6 This is a schematic diagram of the internal structure of the mandrel in this invention; Figure 7 This is a system block diagram provided for the present invention.
[0017] In the diagram, 1. Annular furnace body; 11. Divider plate; 12. Heating zone; 13. Insulation zone; 14. Cooling zone; 15. Loading and unloading zone; 2. Support frame; 3. Core rod; 31. First temperature sensor; 32. Heating wire; 33. Second temperature sensor; 4. Controller; 5. First drive motor; 51. First rotating shaft; 52. Support turntable; 6. Second drive motor; 61. Second rotating shaft; 62. Telescopic component; 63. Lifting plate; 7. Air blowing pipe; 71. First air pipe; 72. Main air pipe; 73. Position sensor; 74. Control valve; 75. Conical guide section. Detailed Implementation
[0018] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.
[0019] Reference Figures 1-7As shown, a high-strength glass tube annealing device includes an annular furnace body 1. The annular furnace body 1 is sequentially divided along its circumference by a partition plate 11 into a heating zone 12, a heat preservation zone 13, a cooling zone 14, and a loading / unloading zone 15. The loading / unloading zone 15 is an open section of the annular furnace body 1, used for feeding the glass tubes to be annealed and discharging the annealed glass tubes. A sealing door is installed on the annular furnace body 1 corresponding to the loading / unloading zone 15 to reduce heat loss. The partition plate 11 is made of high-temperature resistant ceramic material, which can reduce heat flow between the different zones. The heat preservation zone 13... The heating zone 12 can be equipped with conventional nickel-chromium alloy heating wires 32, which are evenly distributed on the inner wall of the heating zone 12 to heat the outer wall of the glass tube to the preheating temperature. The heat preservation zone 13 is equipped with low-power compensation heating elements, which work with the furnace body insulation layer to maintain temperature stability. The cooling zone 14 is equipped with an industrially common cold air curtain mechanism, which cools the outer wall of the glass tube by blowing room temperature air. The above-mentioned heating elements, heat preservation elements and cooling mechanisms are all conventional components that are mature in industry. Their specific installation methods, circuit connections and basic working principles are existing technologies and will not be described in detail here. It also includes a revolution mechanism, an inner wall temperature control component, and a control and adjustment component. The revolution mechanism can rotate along the axis of the annular furnace body 1, and a self-rotation mechanism is provided on the revolution mechanism. A support frame 2 for holding glass tubes is connected to the self-rotation mechanism. In use, the stripped tubes with annealing are inserted one by one into the slots in the support frame. The revolution mechanism includes a first drive motor 5, a first rotating shaft 51, and a support turntable 52. The first drive motor 5 is fixed below the center of the annular furnace body 1 by a motor base. The output end of the first drive motor 5 is connected to the lower end of the first rotating shaft 51 through a coupling. The first rotating shaft 51 is vertically arranged along the axis of the annular furnace body 1, and its upper end extends into the interior of the annular furnace body 1 and is fixedly connected to the center of the support turntable 52. When the first drive motor 5 is started, it can drive the first rotating shaft 51 and the support turntable 52 to rotate stably along the axis of the annular furnace body 1, providing power for the subsequent flow of glass tubes. The inner wall temperature control assembly includes a mandrel 3 corresponding to each glass tube. The mandrel 3 is detachably fitted into the hollow cavity of the glass tube along the axial direction of the glass tube to be annealed via a lifting mechanism. It is used to heat, maintain, and cool the inner wall of the glass tube. The control and adjustment assembly includes a first temperature sensor 31 on the mandrel 3, a heating wire 32 inside the mandrel 3, a second temperature sensor 33 inside the annular furnace body 1, and a controller 4 electrically connected to the first temperature sensor 31 and the second temperature sensor. The controller 4 receives the temperature signals from the first temperature sensor 31 and the second temperature sensor 33, compares the temperature difference between the inner and outer walls of the glass tube, and controls the heating power of the heating wire 32 to change when the temperature difference exceeds a set threshold. Under the action of the lifting mechanism, the mandrel 3 is inserted into the glass tube, and the temperature of the inner wall of the glass tube is monitored by the first temperature sensor 31. The temperature readings of the inner wall of the annular furnace 1, collected by the second temperature sensor 33, are transmitted in real time to the controller 4. The controller 4 has a built-in temperature difference comparison algorithm that compares the two sets of temperature data in real time. When the comparison result shows that the temperature difference exceeds the preset threshold (usually set to ±3℃), the controller 4 outputs an adjustment command: if the inner wall temperature is higher than the outer wall temperature and exceeds the threshold, the controller 4 reduces the power supply of the heating wire 32 to reduce the heat input to the inner wall; if the inner wall temperature is lower than the outer wall temperature and exceeds the threshold, the controller 4 increases the power supply of the heating wire 32 to supplement the heat to the inner wall; when the temperature difference returns to the threshold range, the controller 4 maintains the current power of the heating wire 32 unchanged. Through this closed-loop control logic, the dynamic synchronization of the inner and outer wall temperatures of the glass tube is achieved, ensuring that the temperature difference during the heating and heat preservation stages is always within a reasonable range, and avoiding radial stress caused by the temperature difference. Reference Figure 2 as well as Figure 5 As shown, the rotation mechanism further includes a second drive motor 6 connected to the supporting turntable 52 and a second rotating shaft 61 connected to the output end of the second drive motor 6. The support frame 2 is fixedly connected to the second rotating shaft 61 and is coaxially arranged with the second rotating shaft 61. While the supporting turntable 52 drives the rotation mechanism to revolve around the annular furnace body 1, the support frame 2 can rotate. This ensures that the glass tube is heated and cooled evenly and uniformly, which is the reason for the small differences in local temperature field or uneven distribution of cooling air. This lays the foundation for the control and adjustment components to achieve precise temperature difference control and further improves the annealing quality. Both the first drive motor 5 and the second drive motor 6 can be stepper motors, and their speed can be adjusted by the controller 4. The speed is usually controlled at a level that ensures the glass tube is heated evenly without causing the glass tube to shake due to excessive speed.
[0020] Reference Figure 5As shown, the lifting mechanism further includes a telescopic component 62 installed in the second rotating shaft 61 and a lifting plate 63 connected to the movable end of the telescopic component 62. The lifting plate 63 is slidably connected to the second rotating shaft 61, and the core rod 3 is connected to the lifting plate 63. After the glass tube is installed on the support frame 2, the controller 4 controls the telescopic component 62 to move downward, driving the lifting plate 63 and the core rod 3 to be inserted into the glass tube one by one. The telescopic component 62 is a high-temperature resistant electric push rod, which is suitable for the high-temperature environment inside the second rotating shaft 61. The second rotating shaft 61 adopts a double-layer heat insulation structure. The inner layer is a high-temperature resistant alloy tube, and the outer layer is wrapped with a ceramic fiber heat insulation layer, which can block the heat of the furnace body from being conducted into the shaft and prevent the telescopic component 62 from being affected by high temperature.
[0021] The mandrel 3 is equipped with an air blowing pipe 7. The input end of the air blowing pipe 7 is connected to a first air pipe 71 through a rotary sealing joint. The rotary sealing joint can achieve gas sealing transmission while allowing the air blowing pipe 7 to rotate synchronously with the mandrel 3 and the self-rotation mechanism, thus preventing the air blowing pipe 7 from twisting or breaking due to rotation. The first air pipe 71 is rotatably connected to the first air pipe 71. The input end of the first air pipe 71 is connected to a main air pipe 72 that is rotatably connected to the annular furnace body 1. The main air pipe 72 is connected to an external gas source, which is usually an inert gas. The external gas source can adjust the gas output pressure according to the annealing requirements, so that the inert gas is delivered to the inside of the mandrel 3 in sequence through the main air pipe 72, the first air pipe 71, and the air blowing pipe 7, and is finally used for the cooling of the inner wall of the glass tube. The mandrel 3 is made of high-temperature resistant ceramic material, which has excellent high-temperature resistance and can stably withstand the high temperature environment of 400-650℃ during the annealing process. In addition, the outer diameter of the mandrel 3 is controlled within 1 / 3-1 / 2 of the inner diameter of the glass tube to be annealed, ensuring that there is a sufficient gap between the mandrel 3 and the inner wall of the glass tube, providing a smooth channel for heat transfer and cooling gas flow. Furthermore, a conical guide section 75 with its tip pointing upwards is provided at the bottom opening of the air blowing pipe 7. The conical surface of the conical guide section 75 is smooth and the angle is optimized, which can guide the gas to diffuse evenly in all directions without generating excessive resistance to the gas flow. At the same time, a certain width of annular gap is left between the conical guide section 75 and the bottom opening of the air blowing pipe 7, providing a smooth channel for gas diffusion and avoiding gas stagnation inside the core rod 3. When the inert gas is ejected from the bottom opening of the air blowing pipe 7, it will directly hit the conical surface of the conical guide section 75 and spread rapidly in all directions along the conical surface. Then, it will evenly fill the gap between the core rod 3 and the inner wall of the glass tube through the annular gap, achieving uniform cooling of the entire circumference of the inner wall of the glass tube.
[0022] Reference Figure 4As shown, furthermore, a position sensor 73 is installed on the inner wall of the cooling zone 14 at the location corresponding to the revolution path of the support frame 2. This position sensor 73 uses a high-temperature resistant proximity switch, with its sensing end facing the revolution trajectory of the supporting turntable 52. It is fixed to the inner wall of the annular furnace body 1 by a heat-insulating bracket to avoid direct contact with the high-temperature environment affecting the detection accuracy. It is electrically connected to the controller 4 and can capture the position signal of the support frame 2 in real time. Each first air pipe 71 is connected in series with an independent control valve 74. When the support frame 2 revolves with the supporting turntable 52 into the cooling zone 14, the position sensor 73 detects the support frame 2 and immediately sends a signal to the controller 4. Upon receiving a trigger signal, the controller 4 accurately identifies the pipe number corresponding to the support frame 2 and then outputs a control command to open the control valve 74 on the first air pipe 71 with that number (i.e., the control valve 74 located in the cooling zone 14 at this time). The inert gas supplied by the external air source is then delivered sequentially through the main air pipe 72, the first air pipe 71, and the air blowing pipe 7 to the inside of the mandrel 3 in the cooling zone 14 to perform air blowing cooling on the inner wall of the glass tube. When the support frame 2 revolves away from the cooling zone 14, the position sensor 73 stops sending signals, and the controller 4 synchronously receives the position departure signal and immediately outputs a command to close the corresponding control valve 74, cutting off the gas supply.
[0023] The present invention also provides an annealing method for a high-strength glass tube annealing device, which is implemented based on the above-mentioned high-strength glass tube annealing device and includes the following steps: S1. Loading and mandrel 3 fitting: Place the glass tubes to be annealed one by one on the support frame 2, and drive the lifting plate 63 through the lifting mechanism to drive the mandrel 3 to be inserted along the axial direction of the glass tube. S2. The revolution and rotation start synchronously: The first drive motor 5 drives the supporting turntable 52 to rotate along the axis of the annular furnace body 1, so that the support frame 2 revolves with the supporting turntable 52. At the same time, the second drive motor 6 drives the second rotating shaft 61 and the support frame 2 to rotate around its own axis. The glass tube rotates synchronously with the support frame 2 to achieve uniform heating. S3. Adjustment of temperature difference between inner and outer walls of glass tube: Based on the temperature value of the inner wall of glass tube fed back by the first temperature sensor 31 and the internal temperature of the annular furnace body 1 fed back by the second temperature sensor 33, the power of the heating wire 32 is adjusted in real time by the controller 4 to ensure that the temperature difference between the inner and outer walls is always within the set threshold. S4. Unloading and Resetting: When the glass tube has finished cooling and rotates with the support turntable 52 to the loading and unloading area 15, the controller 4 closes the corresponding control valve 74 and at the same time starts the lifting mechanism to drive the mandrel 3 to be slowly pulled out of the glass tube; the operator removes the annealed glass tube from the support frame 2 and places the new glass tube to be annealed in place to enter the next annealing cycle.
[0024] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A high-strength glass tube annealing device, characterized in that, include; The annular furnace body (1) is divided into a heating zone (12), a heat preservation zone (13), a cooling zone (14) and a loading and unloading zone (15) in sequence by a partition plate (11) along the circumference. The loading and unloading zone (15) is an open section of the annular furnace body (1) and is used for loading the glass tube to be annealed and unloading the glass tube after annealing. The orbital mechanism can rotate along the axis of the annular furnace body (1). The orbital mechanism is equipped with a self-rotation mechanism, and the self-rotation mechanism is connected to a support frame (2) for holding glass tubes. The inner wall temperature control assembly includes a core rod (3) corresponding to each glass tube. The core rod (3) is pluggable into the hollow cavity of the glass tube along the axial direction of the glass tube to be annealed by a lifting mechanism, and is used to heat, keep warm and cool the inner wall of the glass tube. The control and adjustment assembly includes a first temperature sensor (31) disposed on the mandrel (3), an electric heating wire (32) inside the displacement mandrel (3), a second temperature sensor (33) disposed inside the annular furnace body (1), and a controller (4) electrically connected to the first temperature sensor (31) and the second temperature sensor. The controller (4) is used to receive the temperature signals of the first temperature sensor (31) and the second temperature sensor (33), compare the temperature difference between the inner wall and the outer wall of the glass tube, and control the change of the heating power of the electric heating wire (32) when the temperature difference exceeds the set threshold.
2. The high-strength glass tube annealing equipment according to claim 1, characterized in that, The revolution mechanism includes a first drive motor (5) and a first rotating shaft (51) connected to the output end of the first drive motor (5). The first rotating shaft (51) is provided with a support turntable (52) that is rotatably connected to the annular furnace body (1).
3. The high-strength glass tube annealing equipment according to claim 2, characterized in that, The self-rotating mechanism includes a second drive motor (6) connected to the supporting turntable (52) and a second rotating shaft (61) connected to the output end of the second drive motor (6). The support frame (2) is fixedly connected to the second rotating shaft (61) and is coaxial with the second rotating shaft (61).
4. The high-strength glass tube annealing equipment according to claim 3, characterized in that, The lifting mechanism includes a telescopic component (62) installed in the second rotating shaft (61) and a lifting plate (63) connected to the movable end of the telescopic component (62). The lifting plate (63) is slidably connected to the second rotating shaft (61), and the core rod (3) is connected to the lifting plate (63).
5. The high-strength glass tube annealing equipment according to claim 1, characterized in that, The core rod (3) is also provided with an air blowing pipe (7). The input end of the air blowing pipe (7) is rotatably connected to a first air pipe (71). The input end of the first air pipe (71) is connected to a main air pipe (72) rotatably connected to the annular furnace body (1). The main air pipe (72) is connected to an external air source.
6. The high-strength glass tube annealing equipment according to claim 5, characterized in that, A position sensor (73) is provided in the cooling zone (14), and a control valve (74) is provided on the first air pipe (71). The controller (4) is also configured to control the control valve (74) in the corresponding cooling zone (14) to open for air blowing after receiving a signal from the position sensor (73).
7. The high-strength glass tube annealing equipment according to claim 5, characterized in that, The bottom opening of the air blowing pipe (7) is provided with a cone-shaped guide section (75) with the cone tip pointing upward.
8. The high-strength glass tube annealing equipment according to claim 1, characterized in that, The core rod (3) is made of high-temperature resistant ceramic, and the outer diameter of the core rod (3) is 1 / 3 to 1 / 2 of the inner diameter of the glass tube to be annealed.
9. An annealing method for a high-strength glass tube annealing apparatus, based on the high-strength glass tube annealing apparatus described in claims 1-8, characterized in that, Includes the following steps: S1. Loading and mandrel (3) fitting: Place the glass tubes to be annealed one by one on the support frame (2), and drive the lifting plate (63) through the lifting mechanism to drive the mandrel (3) to be inserted along the glass tube axis; S2. The revolution and rotation start synchronously: The first drive motor (5) drives the supporting turntable (52) to rotate along the axis of the annular furnace body (1), so that the support frame (2) revolves with the supporting turntable (52). At the same time, the second drive motor (6) drives the second rotating shaft (61) and the support frame (2) to rotate around their own axis. The glass tube rotates synchronously with the support frame (2) to achieve uniform heating. S3, Adjustment of temperature difference between inner and outer walls of glass tube: The temperature value of the inner wall of glass tube fed back by the first temperature sensor (31) and the internal temperature of the ring furnace body (1) fed back by the second temperature sensor (33) are used to finely adjust the power of the heating wire (32) in real time by the controller (4) to ensure that the temperature difference between inner and outer walls is always within the set threshold. S4. Discharge and Reset: When the glass tube has finished cooling and revolves with the support turntable (52) to the loading and unloading area (15), the controller (4) closes the corresponding control valve (74) and starts the lifting mechanism to drive the mandrel (3) to be slowly pulled out of the glass tube; the operator removes the annealed glass tube from the support frame (2) and places the new glass tube to be annealed in place to enter the next annealing cycle.