High-frequency fiber drawing induction furnace

Abstract

The application relates to the technical field of optical fiber manufacturing, in particular to a high-frequency optical fiber drawing induction furnace. The high-frequency optical fiber drawing induction furnace comprises a furnace body, an air inlet assembly and a temperature measuring assembly. A furnace cavity is formed in the furnace body, and a furnace opening is arranged on the furnace body and communicates with the furnace cavity. The air inlet assembly is arranged at the furnace opening and is used for respectively introducing heat exchange gas into different positions of the furnace cavity. The temperature measuring assembly is arranged on the furnace body and is used for detecting the temperatures of different positions of the furnace cavity. In the production process, the effective flow area of the corresponding air inlet channel can be adjusted according to the temperatures of different positions of the furnace body, the flow of the heat exchange gas at the corresponding position in the furnace can be adjusted, the furnace body and graphite structural members can be rapidly and uniformly cooled when a rod needs to be replaced or the graphite members in the furnace need to be inspected, large thermal stress can be avoided in the graphite members, cracks and deformation of the graphite members can be prevented, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fiber manufacturing, and in particular to a high-frequency optical fiber drawing induction furnace. BACKGROUND

[0002] In the process of optical fiber manufacturing, the high-frequency optical fiber drawing induction furnace is one of the core equipment. After the optical fiber drawing operation is completed, or due to the needs of equipment maintenance, fault diagnosis, process adjustment, etc., the induction furnace needs to be cooled down.

[0003] At present, the cooling is mainly carried out in three ways: natural cooling, air cooling and water cooling. The traditional natural cooling method is extremely slow. For a common high-frequency optical fiber drawing induction furnace, it often takes 3-5 hours to cool down from the working temperature (about 2000℃) to the safe operating temperature (about 50℃), which results in a long idle time of the equipment. The air cooling method also has limited cooling speed and cannot meet the production demand of rapid cooling. Although the water cooling method has a faster cooling speed, due to the complex internal structure of the induction furnace, especially the graphite parts as the key components, the position and structure of the graphite parts in the furnace make it difficult to achieve uniform cooling. During the water cooling process, the temperature change rate of different parts of the graphite parts is quite different, which will cause a large thermal stress in the graphite parts. According to the material mechanics analysis, when the thermal stress exceeds the bearing limit of the graphite parts, the graphite parts are prone to crack, deformation and other damage. Once the graphite parts are damaged, not only the current production task will be affected, but also the high cost and long time of replacing the graphite parts will seriously affect the overall production. At the same time, impurities and other foreign matters in the water are easy to cause pipeline blockage during the circulation in the furnace body, resulting in local high temperature of the furnace body, affecting the service life of the furnace body and causing high maintenance cost. SUMMARY

[0004] The present application provides a high-frequency optical fiber drawing induction furnace to solve the problem that in the prior art, the temperature change rate of different parts of the graphite structure in the induction furnace is quite different, resulting in a large thermal stress in the graphite parts, and the graphite parts are prone to crack, deformation and other damage.

[0005] The present application provides a high-frequency optical fiber drawing induction furnace, comprising:

[0006] a furnace body, an internal cavity is formed in the furnace body, and a furnace opening is formed in the furnace body and connected to the internal cavity;

[0007] an air inlet assembly arranged at the furnace opening and used for introducing heat exchange gas into different positions of the internal cavity;

[0008] a temperature measuring assembly arranged on the furnace body and used for detecting the temperature of different positions of the internal cavity.

[0009] In a possible design, the air inlet assembly comprises a gas distribution ring, which is arranged on the inner wall of the furnace mouth, and at least two layers of air channels are formed in the gas distribution ring, each layer of air channels is distributed along the circumference of the gas distribution ring, the air channels in the same layer have the same angle with the central axis of the gas distribution ring, and the air channels in different layers have different angles with the central axis of the gas distribution ring.

[0010] In a possible design, one end of the air channel is formed in the outer ring wall of the gas distribution ring, and the other end is formed in the inner ring wall of the gas distribution ring, the air channel comprises three layers, namely a first air channel, a second air channel and a third air channel, the angle of the first air channel with the central axis of the gas distribution ring is greater than the angle of the second air channel with the central axis of the gas distribution ring, and the angle of the third air channel with the central axis of the gas distribution ring is the smallest.

[0011] In a possible design, the air inlet assembly further comprises:

[0012] a first air inlet ring, which is sleeved outside the gas distribution ring and has first air holes distributed along the circumference thereof, one end of each first air hole is formed in the outer ring wall of the first air inlet ring, and the other end is formed in the inner ring wall of the first air inlet ring, and the first air inlet ring can adjust the flow of gas flowing through the first air holes and the first air channels by rotating around the central axis of the gas distribution ring;

[0013] a second air inlet ring, which is sleeved outside the gas distribution ring and has second air holes distributed along the circumference thereof, one end of each second air hole is formed in the outer ring wall of the second air inlet ring, and the other end is formed in the inner ring wall of the second air inlet ring, and the second air inlet ring can adjust the flow of gas flowing through the second air holes and the second air channels by rotating around the central axis of the gas distribution ring;

[0014] a third air inlet ring, which is sleeved outside the gas distribution ring and has third air holes distributed along the circumference thereof, one end of each third air hole is formed in the outer ring wall of the third air inlet ring, and the other end is formed in the inner ring wall of the third air inlet ring, and the third air inlet ring can adjust the flow of gas flowing through the third air holes and the third air channels by rotating around the central axis of the gas distribution ring.

[0015] In a possible design, the outer ring faces of the first air inlet ring, the second air inlet ring and the third air inlet ring are respectively provided with external teeth, and the air inlet assembly further comprises a first gear, a second gear and a third gear, the first gear is engaged with the external teeth of the first air inlet ring, the second gear is engaged with the external teeth of the second air inlet ring, and the third gear is engaged with the external teeth of the third air inlet ring.

[0016] In a possible design, angle rotation encoders are respectively installed on the shafts of the first gear, the second gear and the third gear to detect the rotation angles of the corresponding gears.

[0017] In a possible design, the drive is further connected to the wheel shafts of the first gear, the second gear and the third gear respectively, and is configured to drive the corresponding wheel shafts to rotate.

[0018] In a possible design, the temperature measuring assembly includes three groups of temperature measuring components, which are arranged at the upper part, the middle part and the lower part of the furnace cavity respectively.

[0019] In a possible design, the temperature measuring assembly includes:

[0020] The sleeve is arranged in the side wall of the furnace body.

[0021] The thermocouple is arranged in the sleeve and extends into the furnace cavity.

[0022] The fastening ring is arranged in the sleeve and is arranged close to the outer end of the thermocouple.

[0023] The spring is arranged in the sleeve and abuts against one end of the outer end of the thermocouple and the other end of the fastening ring.

[0024] The junction box is arranged at the outer end of the sleeve.

[0025] The signal lead wire is arranged to pass through the fastening ring and electrically connect the thermocouple and the junction box.

[0026] In a possible design, the furnace body is further connected to the air inlet pipe, and the air inlet pipe is configured to introduce the heat exchange gas to the position of the furnace cavity away from the central axis; and / or, the side wall of the furnace body has a vacuum interlayer.

[0027] The application has the following beneficial effects:

[0028] The high-frequency optical fiber drawing induction furnace provided by the application can introduce low-temperature nitrogen gas for heat exchange to different positions of the furnace cavity through the air inlet assembly, can simultaneously cool different positions of the furnace body, can maximize the consistency of the cooling speed of the structural members at different positions in the furnace, and can effectively control the structural members in the furnace body to be in a suitable temperature range. The temperature measuring assembly can be used to adjust the effective flow area of the corresponding air inlet channel and the flow of the heat exchange gas at the corresponding position in the furnace according to the temperature of the different positions of the furnace body during production, can quickly and uniformly cool the furnace body and the structural members such as graphite when a rod needs to be replaced or the graphite members in the furnace need to be inspected, can avoid the generation of a large thermal stress in the graphite members, can prevent the graphite members from being damaged, such as cracks and deformation, and can prolong the service life. The temperature of the graphite members in the furnace can be reduced to below 100 DEG C within 0.5 to 1 hour, and the cooling time can be shortened by 2 to 3 times. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art of the present application, the drawings needed to be used in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0030] Figure 1 The structural schematic diagram of the high-frequency optical fiber drawing induction furnace provided by the embodiments of the present application is shown in the figure.

[0031] Figure 2 The structural schematic diagram of the gas inlet assembly of the high-frequency optical fiber drawing induction furnace provided by the embodiments of the present application is shown in the figure.

[0032] Figure 3 Another structural schematic diagram of the gas inlet assembly of the high-frequency optical fiber drawing induction furnace provided by the embodiments of the present application is shown in the figure.

[0033] Figure 4 The structural schematic diagram of the temperature measuring assembly of the high-frequency optical fiber drawing induction furnace provided by the embodiments of the present application is shown in the figure.

[0034] Reference signs:

[0035] 100, furnace body; 110, furnace mouth; 120, first furnace cavity; 130, second furnace cavity; 200, gas inlet assembly; 210, gas distribution ring; 211, first gas channel; 212, second gas channel; 213, third gas channel; 220, first gas inlet ring; 221, first gas hole; 230, second gas inlet ring; 231, second gas hole; 240, third gas inlet ring; 241, third gas hole; 250, first gear; 260, second gear; 270, third gear; 300, temperature measuring assembly; 310, sleeve; 320, thermocouple; 330, fastening ring; 340, spring; 350, junction box; 360, signal lead; 400, gas inlet pipe; 500, vacuum interlayer; 600, graphite piece. DETAILED DESCRIPTION

[0036] The technical solutions of the present application will be described in detail below in combination with embodiments. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] The technical solutions of the present application will be described in detail below in combination with embodiments. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. Figures 1-4The high-frequency optical fiber drawing induction furnace provided in the embodiments of the application is described. The high-frequency optical fiber drawing induction furnace comprises a furnace body 100, an air inlet assembly 200, and a temperature measurement assembly 300. The furnace body 100 has a furnace cavity formed inside, and the furnace body 100 is provided with a furnace opening 110 that is in communication with the furnace cavity. A graphite heating element or the like is generally arranged at a position close to the central axis of the furnace cavity, and is used to heat an optical rod during the drawing process. The optical rod enters the furnace cavity from the furnace opening 110, and is drawn out from the lower end of the furnace body 100 after drawing. When the optical rod needs to be replaced or the graphite element 600 in the furnace needs to be inspected, the furnace cavity needs to be rapidly cooled. The air inlet assembly 200 is arranged at the furnace opening 110, and is used to respectively introduce heat exchange gas into different positions of the furnace cavity. The heat exchange gas is low-temperature nitrogen, and the low-temperature nitrogen can rapidly cool the graphite element 600 in the furnace. The temperature measurement assembly 300 is arranged on the furnace body 100, and is used to detect the temperature of different positions of the furnace cavity.

[0038] Referring to Figure 1 , Figure 2 In some specific embodiments, the air inlet assembly 200 comprises a gas distribution ring 210, which is fixed to the inner wall of the furnace opening 110. At least two layers of gas channels are formed in the gas distribution ring 210, and each layer of gas channels is distributed along the circumference of the gas distribution ring 210. The axial angle of the gas channels in the same layer is the same as the central axis of the gas distribution ring 210, and the axial angle of the gas channels in different layers is different from the central axis of the gas distribution ring 210. One end of the gas channel is formed in the outer ring wall of the gas distribution ring 210, and the other end is formed in the inner ring wall of the gas distribution ring 210. Specifically, the gas channel comprises three layers, namely the first gas channel 211, the second gas channel 212, and the third gas channel 213 from top to bottom. The axial angle of the first gas channel 211 is greater than the axial angle of the second gas channel 212, and the axial angle of the second gas channel 212 is greater than the axial angle of the third gas channel 213. In this way, the heat exchange gas blown out by the first gas channel 211 corresponds to the upper part of the furnace cavity, the heat exchange gas blown out by the second gas channel 212 corresponds to the middle part of the furnace cavity, and the heat exchange gas blown out by the third gas channel 213 corresponds to the lower part of the furnace cavity. The different positions of the furnace body are cooled at the same time, the cooling speed of the structural elements at different positions in the furnace is kept as consistent as possible, the internal thermal stress of the graphite element 600 is avoided, and the graphite element 600 is prevented from being damaged, such as cracking and deformation.

[0039] Referring to Figure 2As shown, in some embodiments, the air inlet assembly 200 further comprises a first air inlet ring 220, a second air inlet ring 230 and a third air inlet ring 240, the furnace opening 110 is formed with an annular groove recessed towards the furnace wall, the first air inlet ring 220, the second air inlet ring 230 and the third air inlet ring 240 are correspondingly arranged in the annular groove, and a pipeline is connected to the position of the annular groove for conveying heat exchange gas into the annular groove. Specifically, the first air inlet ring 220 is sleeved outside the air distribution ring 210, the first air inlet ring 220 is provided with first air holes 221 distributed along the circumference thereof, one end of the first air holes 221 is opened on the outer ring wall of the first air inlet ring 220, and the other end is opened on the inner ring wall of the first air inlet ring 220, the first air holes 221 are in communication with the first air duct 211, the first air inlet ring 220 can adjust the overlapping cross-sectional area of the first air holes 221 and the first air duct 211 by rotating around the central axis of the air distribution ring 210, thereby adjusting the gas flow rate flowing through the first air holes 221 and the first air duct 211 within the same time.

[0040] The second air inlet ring 230 is sleeved outside the air distribution ring 210, the second air inlet ring 230 is provided with second air holes 231 distributed along the circumference thereof, one end of the second air holes 231 is opened on the outer ring wall of the second air inlet ring 230, and the other end is opened on the inner ring wall of the second air inlet ring 230, the second air holes 231 are in communication with the second air duct 212, the second air inlet ring 230 can adjust the overlapping cross-sectional area of the second air holes 231 and the second air duct 212 by rotating around the central axis of the air distribution ring 210, thereby adjusting the gas flow rate flowing through the second air holes 231 and the second air duct 212.

[0041] The third air inlet ring 240 is sleeved outside the air distribution ring 210, the third air inlet ring 240 is provided with third air holes 241 distributed along the circumference thereof, one end of the third air holes 241 is opened on the outer ring wall of the third air inlet ring 240, and the other end is opened on the inner ring wall of the third air inlet ring 240, the third air holes 241 are in communication with the third air duct 213, the third air inlet ring 240 can adjust the overlapping cross-sectional area of the third air holes 241 and the third air duct 213 by rotating around the central axis of the air distribution ring 210, thereby adjusting the gas flow rate flowing through the third air holes 241 and the third air duct 213.

[0042] Referring to Figure 3As shown, in some embodiments, the outer ring surfaces of the first air inlet ring 220, the second air inlet ring 230, and the third air inlet ring 240 are respectively provided with external teeth, and the air inlet assembly 200 further comprises a first gear 250, a second gear 260, a third gear 270, and a driver. The first gear 250 is in mesh with the external teeth of the first air inlet ring 220, the second gear 260 is in mesh with the external teeth of the second air inlet ring 230, and the third gear 270 is in mesh with the external teeth of the third air inlet ring 240. The driver is an electric motor, which is respectively connected to the shafts of the first gear 250, the second gear 260, and the third gear 270 for driving the corresponding shafts to rotate. In this way, the gas flow rates of the first air passage 211, the second air passage 212, and the third air passage 213 can be adjusted by driving the shafts of the first gear 250, the second gear 260, and the third gear 270 to rotate by appropriate angles. In some embodiments, an angle rotary encoder is respectively installed on the shaft of each of the first gear 250, the second gear 260, and the third gear 270 for detecting the rotation angle of the corresponding gear.

[0043] In some embodiments, the temperature measurement assembly 300 comprises three groups, which are respectively arranged on the furnace body 100 and located on the extension lines of the first air passage 211, the second air passage 212, and the third air passage 213 for detecting the temperatures of the upper part, the middle part, and the lower part of the furnace cavity. Specifically, each temperature measurement assembly 300 comprises a sleeve 310, a thermocouple 320, a fastening ring 330, a spring 340, a junction box 350, and a signal lead 360. The sleeve 310 is arranged in the sidewall of the furnace body 100. The thermocouple 320 is arranged in the sleeve 310, and the inner end of the thermocouple 320 extends into the furnace cavity. The fastening ring 330 is arranged in the sleeve 310 and close to the outer end of the thermocouple 320. The spring 340 is arranged in the sleeve 310, one end of the spring 340 abuts against the outer end of the thermocouple 320, and the other end of the spring 340 abuts against the fastening ring 330. The junction box 350 is arranged at the outer port of the sleeve 310. The signal lead 360 is arranged to pass through the fastening ring 330, so that the thermocouple 320 is electrically connected to the junction box 350. The signal lead is connected to the external circuit of the controller through a terminal in the junction box 350 for signal transmission. When the thermocouple is installed, the spring generates a spring force to keep the measurement end of the thermocouple in close contact with the graphite member. In particular, in the case of slight shaking of the furnace body, the spring can play a buffering and compensating role to prevent the thermocouple from being separated from or poorly contacting the bottom of the sleeve, thereby ensuring the stability of the measurement. During the temperature change in the furnace, the thermocouple, the sleeve, and the surrounding furnace body material will all expand and contract due to heat. The spring can adapt to these size changes by itself, avoiding damage to the thermocouple or the sleeve due to thermal stress.

[0044] The cooling process of the high-frequency optical fiber drawing induction furnace of the present application is as follows:

[0045] The thermocouple 320 collects the temperature near the graphite piece. After the controller receives the temperature signal collected by the thermocouple 320, the rotation angle is set according to the temperature signal collected by the thermocouple 320, and a start instruction is sent to the corresponding driver to drive the corresponding wheel shaft to rotate. At the same time, the angle rotary encoder on the wheel shaft sends the collected rotation angle information to the controller. After the corresponding first gear 250 or second gear 260 or third gear 270 rotates to the target angle, the controller sends a stop instruction to the corresponding driver.

[0046] Specifically, when the temperature difference detected by the temperature measuring assembly 300 at the upper, middle and lower parts of the furnace cavity is within a suitable range, for example, within 5-10℃, the driver does not act; when the temperature difference detected by the temperature measuring assembly 300 at the upper, middle and lower parts of the furnace cavity exceeds the above range, the driver will drive the lowest and highest values in the three to act. Taking the example of the lowest temperature at the upper part of the furnace cavity and the highest temperature at the lower part of the furnace cavity:

[0047] The driver connected with the first air inlet ring 220 acts to make the first air inlet ring 220 rotate around the central axis of the air distribution ring 210, so as to reduce the overlapping cross-sectional area of the first air hole 221 and the first air duct 211, and further reduce the flow rate of the low-temperature nitrogen gas flowing through the first air hole 221 and the first air duct 211 within the same time;

[0048] The driver connected with the third air inlet ring 240 acts to make the third air inlet ring 240 rotate around the central axis of the air distribution ring 210, so as to increase the overlapping cross-sectional area of the third air hole 241 and the third air duct 213, and further increase the flow rate of the low-temperature nitrogen gas flowing through the first air hole 221 and the first air duct 211 within the same time. In this way, the furnace body and the graphite piece can be rapidly and uniformly cooled, avoiding large thermal stress on the upper and lower parts of the graphite piece 600, preventing damage such as cracks and deformation of the graphite piece 600, and improving the service life of the induction furnace.

[0049] Referring to Figure 1 In some embodiments, the side wall of the furnace body 100 has a vacuum interlayer 500 for heat preservation in the furnace. The furnace body 100 is also connected with an air inlet pipe 400, which communicates with the position of the furnace cavity away from the central axis. In this way, the air inlet pipe 400 is used to introduce heat exchange gas into the position of the furnace cavity away from the central axis (the second furnace cavity 130 in Figure 1 The air distribution ring 210 is used to introduce heat exchange gas into the position of the furnace cavity close to the central axis (the first furnace cavity 120 in Figure 1 The air inlet pipe 400 and the air distribution ring 210 can cooperate to cool the inner and outer sides of the graphite piece 600 in the furnace cavity, avoiding large thermal stress on the inner and outer sides of the graphite piece 600.

[0050] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0051] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0052] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0054] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A high frequency optical fiber drawing induction furnace, characterized by, The application relates to a high-frequency optical fiber drawing induction furnace. The furnace body is internally formed with a furnace cavity, and the furnace body is provided with a furnace opening communicating with the furnace cavity. The gas distribution ring is provided with three layers of gas channels, namely a first gas channel, a second gas channel and a third gas channel. The first gas channel, the second gas channel and the third gas channel are arranged in the circumferential direction of the gas distribution ring. The first gas channel, the second gas channel and the third gas channel are arranged in the circumferential direction of the gas distribution ring. The first gas hole is arranged in the outer ring wall of the first gas inlet ring and the inner ring wall of the first gas inlet ring. The second gas hole is arranged in the outer ring wall of the second gas inlet ring and the inner ring wall of the second gas inlet ring. The third gas hole is arranged in the outer ring wall of the third gas inlet ring and the inner ring wall of the third gas inlet ring. The outer ring surface of the first gas inlet ring, the second gas inlet ring and the third gas inlet ring is respectively provided with external teeth.

2. The high-frequency optical fiber drawing induction furnace according to claim 1, characterized in that: The first gear is in mesh with the external teeth of the first gas inlet ring.

3. The high-frequency optical fiber draw induction furnace of claim 2, wherein: The second gear is in mesh with the external teeth of the second gas inlet ring. The third gear is in mesh with the external teeth of the third gas inlet ring. The first gas inlet ring, the second gas inlet ring and the third gas inlet ring are respectively provided with external teeth. The first gear is in mesh with the external teeth of the first gas inlet ring. The second gear is in mesh with the external teeth of the second gas inlet ring.

5. The high-frequency optical fiber draw induction furnace of claim 4, wherein: The third gear is in mesh with the external teeth of the third gas inlet ring.

6. The high-frequency optical fiber draw induction furnace of claim 5, wherein: The wheel shafts of the first gear, the second gear and the third gear are respectively provided with angle rotary encoders for detecting the rotation angle of the corresponding gears.

7. The high-frequency optical fiber draw induction furnace of claim 6, wherein: The drive is respectively connected with the wheel shaft of the first gear, the second gear and the third gear for driving the corresponding wheel shaft to rotate.

8. The high-frequency fiber drawing induction furnace according to any one of claims 1 to 7, characterized in that The temperature measuring assembly comprises: A sleeve is arranged in the side wall of the furnace body. A thermocouple is arranged in the sleeve and extends into the furnace cavity. A fastening ring is arranged in the sleeve and is close to the outer end of the thermocouple. A spring is arranged in the sleeve and abuts against one end of the outer end of the thermocouple and the other end of the fastening ring. A junction box is arranged at the outer end of the sleeve. A signal lead wire is arranged to pass through the fastening ring to electrically connect the thermocouple and the junction box.

9. High-frequency optical fiber drawing induction furnace according to any one of claims 1 to 7, characterized in that: The furnace body is further connected with an air inlet pipe for introducing heat exchange gas to the position away from the central axis of the furnace cavity; and / or the side wall of the furnace body has a vacuum interlayer.

Images