CN207933273U - a kind of fibre drawing furnace - Google Patents

Abstract

The utility model discloses an optical fiber drawing furnace, which belongs to the technical field of optical fiber production equipment. The fiber drawing furnace includes a furnace body, a heat insulator, a heating body, a driving rotating device and a heater, the heat insulating body is arranged in the furnace body and wraps the heating body, and the driving rotating device is used to drive the The heating body rotates, the heater is arranged on the periphery of the furnace body, and the heater includes a heating coil. When the optical fiber is drawn, the optical fiber preform passes through the hollow space inside the heating body for drawing. On the one hand, the optical fiber drawing furnace reduces the volume of the furnace body, simplifies the structure, reduces the amount of inert gas introduced, reduces energy consumption, and saves costs; on the other hand, the structure of the optical fiber drawing furnace can also form a uniform The stable thermal field improves the stability of optical fiber production, facilitates the production of optical fibers with good performance, and can be widely used in the technical field of optical fiber production.

Description

An optical fiber drawing furnace

technical field

The utility model relates to the technical field of optical fiber production equipment, in particular to an optical fiber drawing furnace.

Background technique

The drawing of optical fiber is to melt the large-diameter optical fiber preform online and draw it into an optical fiber with a diameter that meets the requirements. The heating device for melting the optical fiber preform (usually called a drawing furnace) is one of the most critical equipment in the drawing process. , PMD and fiber geometry parameters, etc.

At present, there are two kinds of fiber drawing furnaces commonly used in the process: DC resistance heating furnace and AC induction heating furnace. Among them, the main working principle of the DC resistance heating furnace is: the low-resistance graphite heating body is fed into the DC electric heating, the graphite central tube is heated by heat conduction, and then the heat is conducted to the preform, and the preform is heated to a molten state and then drawn into an optical fiber. There are often technical problems in DC resistance heating: (1) When the diameter of the preform becomes larger, the required heating power and the size of the heating body also increase accordingly. When the power supply voltage is constant, increasing the power requires reducing the resistance of the heater. value, and the larger the size of the heating body will cause the resistance value to become larger, that is to say, there is an extreme value in the size of the resistance heating furnace, which is not conducive to the miniaturization of the furnace body when a certain power of the heating furnace must be guaranteed; (2) due to Heating the preform needs to pass through the two-layer heat conduction of the graphite heating body and the graphite central tube, and the energy loss is large, which is not conducive to improving energy utilization and saving energy consumption. The main working principle of the AC induction heating furnace is: the (water-cooled) copper spiral coil is fed with medium-frequency alternating current to generate an alternating induction magnetic field. Preform, which is heated to a molten state and then drawn into an optical fiber. Although the AC induction heating furnace does not have the problem of the extreme value of the furnace body size caused by the increase in resistance, it does have the following technical defects: (1) The resistance loss of the copper coil reduces the efficiency of the heating device. Practice has proved that in some cases the heating efficiency is only It can reach 50%-60%; (2) In order to prevent excessive energy consumption caused by coil heating furnace shell and other components, it is often necessary to design complex structures. This is because several measures need to be taken between the outside of the coil and the stainless steel furnace shell to prevent the coil from heating the furnace shell: a sufficient safety distance must be ensured between the two, the farther the better, preferably not less than the inner diameter of the coil; Adding a magnetic isolation device on the inner wall of the furnace shell will cause the drawing furnace to have a large volume and many cavities, which will also lead to increased costs and increased difficulty in heat preservation of the furnace body. At the same time, due to the larger furnace body volume, more process gas needs to be used , which is not conducive to the stability of the thermal field.

Utility model content

In order to solve the problems in the prior art, the embodiment of the utility model provides an optical fiber drawing furnace. Described technical scheme is as follows:

An optical fiber drawing furnace is provided, comprising a furnace body, a heat insulating body, a heating body, a driving and rotating device, and a heater, the heat insulating body is arranged in the furnace body and wraps the heating body, and the driving and rotating device is used for In order to drive the heating body to rotate, the heater is arranged on the periphery of the furnace body, and the heater includes a heating coil. When the optical fiber is drawn, the optical fiber preform passes through the hollow space inside the heating body for drawing.

Preferably, the driving and rotating device includes: a hollow rotating table and a driving motor, the heating body is arranged on the hollow rotating table, and the driving motor is used to drive the hollow rotating table to drive the heating body to rotate.

Preferably, the driving rotation device further includes a PLC control system. Through the PLC control system, the drive motor can be controlled to drive the hollow rotary table to rotate accordingly according to the preset requirements, and the rotation speed can be adjusted according to the relevant requirements of optical fiber preform drawing, so as to facilitate the real-time adjustment and control of the optical fiber drawing furnace.

Preferably, the heating coil is a high-temperature superconductor material coil. Due to its good superconducting performance, it becomes a superconducting magnet after being energized at a certain temperature to form a strong magnetic field. The connection between the heating body and the heating coil Relative movement, the strong magnetic field of the superconducting coil and the magnetic field of the heating body work together to form a strong alternating magnetic field; the fiber drawing furnace is also equipped with a refrigerator, which is used to cool the heating coil The temperature is lowered to meet the working temperature of the superconducting coil.

Preferably, the heating coil is in the shape of a spiral tube.

Preferably, the heater is fixed on the bracket.

Preferably, the heater is connected to a DC power source. Since the optical fiber drawing furnace itself can form an alternating magnetic field capable of generating electromagnetic induction eddy current heating without connecting AC power, the heater can be directly connected to DC power, and the heater is connected to a DC power supply, thereby reducing power costs.

The beneficial effects brought by the technical solution provided by the embodiment of the utility model are:

(1) During the fiber drawing process, the heater is completely separated from the optical fiber preform, which can reduce the size of the furnace body (metal container or furnace shell), because the furnace body needs to ensure sealing, and the processing accuracy is required The furnace body is very tall, and the smaller size of the furnace body can reduce the material of the furnace body and reduce the difficulty of manufacturing and processing the furnace body.

(2) Small furnace cavity, a small amount of inert protective gas can protect graphite parts from burning at high temperature, reduce the consumption of graphite parts and gas, and reduce costs;

(3) The smaller-volume drawing furnace can ensure the uniform distribution of heat and timely response, forming a uniform thermal field;

(4) Since the furnace temperature and other performance indicators can be adjusted in time by adjusting the corresponding device according to the demand, the magnetic field formed by the heater of this wire drawing furnace is more uniform than that of the traditional wire drawing furnace, and the thermal field formed in this way is also more uniform and stable, which is beneficial to optical fiber production stability;

(5) Under the same working conditions, this wire drawing furnace saves at least 30% of power consumption compared with the original wire drawing furnace, and the utilization rate of electric energy is increased to more than 90%, which reduces energy consumption.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of an optical fiber drawing furnace provided by an embodiment of the present invention.

Explanation of reference signs:

1-furnace body, 2-heat insulation layer, 3-heating body, 4-driving rotating device, 5-heater, 6-optical fiber preform.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described implementation Example is only a part of embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be noted that the descriptions of the utility model on directions such as "directly below" and "upper" are all defined based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description. It is not intended to indicate or imply that the device described must be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.

The embodiment of the utility model provides an optical fiber drawing furnace. Due to the structural setting of the optical fiber drawing furnace, the heater is arranged outside the furnace body, and a stable strong magnetic field is formed by driving the heating body to rotate, which is compatible with the heating outside the furnace body. The coils work together to realize electromagnetic induction eddy current heating even when the DC power is connected, thus forming a relatively stable and adjustable thermal field in the furnace body. On the one hand, the optical fiber drawing furnace reduces the volume of the furnace body, simplifies the structure, reduces the amount of inert gas introduced, reduces energy consumption, and saves costs; on the other hand, the structure of the optical fiber drawing furnace can also form a uniform The stable thermal field improves the stability of optical fiber production, facilitates the production of optical fibers with good performance, and can be widely used in the technical field of optical fiber production.

The optical fiber drawing furnace and the optical fiber drawing method provided by the embodiments of the present utility model will be further described below in conjunction with specific embodiments and drawings.

Fig. 1 is a schematic structural diagram of an optical fiber drawing furnace provided by an embodiment of the present invention. As shown in Figure 1, the optical fiber drawing furnace provided by the embodiment of the utility model includes a furnace body 1, a heat insulator 2, a heating body 3, a driving and rotating device 4 and a heater 5, and the order from inside to outside is: heating body 3 , Insulator 2 and furnace body 1. When the optical fiber is drawn, the optical fiber preform rod 6 is drawn through the hollow space in the heating body 3 . Preferably, the heating body 3 is made of high-purity graphite, because it has the characteristics of high temperature resistance and low resistance. The heating body 3 can also be made of any other possible materials in the prior art. The embodiment of the present invention is not correct. It imposes special restrictions. In addition, the heat insulator 2 is set in the furnace body 1 and wraps the heating body 3 to play the role of heat insulation. Preferably, the heat insulator 2 is made of carbon fiber heat insulating material. The heat insulator 2 can also be made of existing It can be made of any other possible materials in the technology, and the embodiment of the utility model does not impose special limitations on it. Preferably, the furnace body 1 is made of non-metallic material, and has the characteristics of high temperature resistance, insulation, and non-magnetic conduction. Similarly, the furnace body 1 can also be made of any other possible materials in the prior art. subject to special restrictions. The furnace body 1, the heat insulator 2 and the heating body 3 together constitute the heating chamber of the fiber drawing furnace. During fiber drawing, the heating chamber is filled with corresponding inert gas to ensure that the gas atmosphere inside meets the requirements and is in a sealed state. . Preferably, an inert protective gas such as argon (Ar), helium (He), nitrogen (N) is passed into the heating chamber.

The driving rotating device 4 is used to drive the heating body 3 to rotate. Preferably, the driving rotating device 4 includes: a hollow rotating table and a driving motor. The hollow rotating table has a hollow structure inside, and the hollow rotating table remains coaxially installed on the furnace body. Directly below the body 1, the heating body 3 is arranged on the hollow rotary table, and the driving motor is used to drive the hollow rotary table to drive the heating body to rotate. In another embodiment, in order to facilitate the setting of the overall structure or to ensure the sealing of the furnace body 1, the following structural setting method can also be adopted: the heating chamber composed of the furnace body 1, the heat insulating body 2, and the heating body 3 is integrally installed On the hollow rotary table, it is ensured that the furnace body 1, the heat insulator 2 and the heating body 3 rotate coaxially with the hollow rotary table during rotation. Further preferably, the driving rotation device further includes a PLC control system (not shown in the figure). Through the PLC control system, the drive motor can be controlled to drive the hollow rotary table to rotate accordingly according to the preset requirements, and the rotation speed can be adjusted according to the relevant requirements of optical fiber preform drawing, so as to facilitate the real-time adjustment and control of the optical fiber drawing furnace.

The heater 5 is arranged on the periphery of the furnace body 1, and preferably the heater 5 is fixed on a support (not shown in the figure). Specifically, the heater 5 includes a heating coil. Preferably, the heating coil is in the shape of a spiral tube. In addition, preferably, the heating coil is a high-temperature superconductor material coil, that is, the coil is made of a high-temperature superconductor (HTS) material. Due to its good superconducting properties, it becomes A superconducting magnet forms a strong magnetic field. Due to the relative movement of the heating body 3 and the heating coil, the strong magnetic field of the superconducting coil and the magnetic field of the heating body 3 act together to form a strong alternating magnetic field, which is generated by the alternating magnetic field. The eddy current heating by electromagnetic induction conducts the heat to the heating body 3 , thereby realizing the drawing process of the optical fiber preform 6 . In order to meet the working temperature requirements of the above-mentioned superconducting coils, in addition to the heat insulator 2 and the furnace body 1 arranged between the heater 5 and the heating body 3 in the furnace body 1 can prevent the heat generated by wire drawing from affecting the superconducting coils, the optical fiber drawing furnace A refrigerator is also provided at the corresponding position, and the refrigerator is used for cooling and cooling the superconducting coil so as to satisfy the working temperature of the superconducting coil.

In addition, preferably, since the fiber drawing furnace itself can form an alternating magnetic field that can generate electromagnetic induction eddy current heating without connecting to AC power, the heater can be directly connected to DC power, and the heater is connected to a DC power supply, reducing power costs.

To sum up, the fiber drawing furnace provided by the embodiment of the utility model arranges the heater including the heating coil outside the furnace body, and drives the heating body in the furnace body to rotate by driving the rotating device. Since the heating body with good conductivity As it rotates, it works together with the external heating coil to form an alternating magnetic field, and the eddy current heating is generated inside and heated, so as to realize the fiber drawing work. The optical fiber drawing furnace based on this structure can realize at least the following three adjustments: (1) the adjustment of the hot zone can be easily realized by adjusting the relative position of the heater and the heating chamber; The higher the frequency of the alternating magnetic field, the smaller the inductive heating penetration distance of the heated object, so that the heating range can be adjusted and controlled by adjusting the rotation speed; (3) According to the process conditions required for the fiber drawing process, including process temperature and process Gas and other indicators, comprehensively adjust the heater power, the rotation speed of the heating body, the relative position relationship between the heater and the heating chamber, and the amount of inert gas introduced to form a more uniform magnetic field in the wire drawing furnace, so that the formed thermal field is also more uniform Stable, which is conducive to maintaining the stability of the fiber drawing process.

In addition, the optical fiber drawing method using the optical fiber drawing furnace described in the above scheme includes the following steps:

Before the fiber drawing furnace is opened, the preparation work before fiber drawing is done, including the inert gas introduction and sealing work inside the fiber drawing furnace;

Turn on the fiber drawing furnace and turn on the heater for heating;

Turn on the driving and rotating device, and the heating body in the furnace body will rotate under the driving of the driving and rotating device;

When it is determined that the drawing conditions in the optical fiber drawing furnace meet the requirements, the drawing of the optical fiber preform is carried out.

In a preferred embodiment, the driving rotating device is turned on, and the heating body in the furnace body rotates under the driving of the driving rotating device, and this process is carried out as follows:

Turn on the drive rotation device, and under the control of the PLC control system, the drive motor drives the hollow rotary table to drive the heating body to rotate.

In addition, when the heating coil of the heater is made of a high-temperature superconductor coil, in order to cool down the heating coil of the heater, the above optical fiber drawing method also includes:

Turn on the refrigerator to cool the heating coil of the heater to the preset heating temperature.

The fiber drawing furnace provided by the embodiment of the utility model has the following intentional effects:

(1) During the fiber drawing process, the heater is completely separated from the optical fiber preform, which can reduce the size of the furnace body (metal container or furnace shell), because the furnace body needs to ensure sealing, and the processing accuracy is required The furnace body is very tall, and the smaller size of the furnace body can reduce the material of the furnace body and reduce the difficulty of manufacturing and processing the furnace body.

(2) Small furnace cavity, a small amount of inert protective gas can protect graphite parts from burning at high temperature, reduce the consumption of graphite parts and gas, and reduce costs;

(3) The smaller-volume drawing furnace can ensure the uniform distribution of heat and timely response, forming a uniform thermal field;

(4) Since the furnace temperature and other performance indicators can be adjusted in time by adjusting the corresponding device according to the demand, the magnetic field formed by the heater of this wire drawing furnace is more uniform than that of the traditional wire drawing furnace, and the thermal field formed in this way is also more uniform and stable, which is beneficial to optical fiber production stability;

(5) Under the same working conditions, this wire drawing furnace saves at least 30% of power consumption compared with the original wire drawing furnace, and the utilization rate of electric energy is increased to more than 90%, which reduces energy consumption.

It should be noted that when the optical fiber drawing furnace provided in the above-mentioned embodiment performs the fiber drawing work, the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned function distribution can be completed by different functional modules according to the needs. , which divides the internal structure of the device into different functional modules to complete all or part of the functions described above. In addition, the optical fiber drawing method provided by the above-mentioned embodiments belongs to the same idea as the embodiment of the optical fiber drawing furnace, and its specific implementation process is detailed in the method embodiment, and will not be repeated here.

All the optional technical solutions mentioned above can be combined in any way to form optional embodiments of the present invention, which will not be repeated here.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above embodiments can be completed by hardware, and can also be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned The storage medium mentioned may be a read-only memory, a magnetic disk or an optical disk, and the like.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (7)

1. a kind of fibre drawing furnace, which is characterized in that including furnace body, heat insulator, calandria, driving rotating device and heating Device, the heat insulator are set in the furnace body and wrap up the calandria, and the driving rotating device is for driving the heating Body rotates, and the heater is set to furnace body periphery, and the heater includes heating coil, preform when drawing optical fibers Hollow space inside the calandria is drawn.

2. fibre drawing furnace according to claim 1, which is characterized in that the driving rotating device includes：Hollow rotating Platform and driving motor, the calandria are set on the hollow rotating platform, and the driving motor is for driving the hollow rotating Platform drives the calandria rotation.

3. fibre drawing furnace according to claim 2, which is characterized in that the driving rotating device further includes PLC controls System.

4. fibre drawing furnace according to claim 1, which is characterized in that the heating coil is high-temperature superconductor material line Circle, the fibre drawing furnace are additionally provided with refrigeration machine, and the refrigeration machine is used to be the heating coil refrigeration cool-down.

5. fibre drawing furnace according to claim 1, which is characterized in that the heating coil is helically coiled.

6. fibre drawing furnace according to claim 1, which is characterized in that the heater is fixed on holder.

7. fibre drawing furnace according to any one of claims 1 to 6, which is characterized in that the heater and DC power supply Connection.