WO2019153473A1 - Optical fiber drawing and annealing device and optical fiber - Google Patents

Abstract

An optical fiber drawing and annealing device and an optical fiber. The optical fiber drawing and annealing device comprises a drawing furnace, a fixed annealing pipe (5), a movable annealing pipe (6), and a driving part for driving the movable annealing pipe (6) to move. The movable annealing pipe (6) comprises an outer pipe (12), a graphite liner (11) fixedly mounted in the outer pipe (12), and a first gas blowing part (9) mounted on the lower end portion of the outer pipe (12) and supplying inert gas into the movable annealing pipe (6); the first gas blowing part (9) comprises a housing (13) and flow guide blocks (14) mounted in the housing (13); an upper flow guide channel (15) and a lower flow guide channel (16) respectively conveying the inert gas to the upper end and lower end of the movable annealing pipe (6) are provided on the flow guide block (14). Microcracks are reduced by reducing the inner stress of the optical fiber, and optical fiber attenuation is finally reduced; moreover, silicon carbide deposited in the drawing furnace and the opening of the annealing pipe is collected in a waste gas collection plate at the opening of the drawing furnace by blowing air downwardly, thereby effectively improving the strength of the optical fiber and drawing efficiency.

Description

 Fiber drawing annealing device and fiber

Technical field

The invention relates to an optical fiber production device, in particular to an optical fiber drawing annealing device and an optical fiber.

Background technique

Nowadays, the domestic fiber drawing process is basically stable. The length of the temperature field of the usual wire drawing annealing device is short and the minimum temperature in the temperature field is high. For example, the annealing device disclosed in the patent application No. CN106019465A has an inert gas entering from above the drawing furnace. During the downward flow of the inert gas, the temperature of the gas is getting higher and higher, so that the temperature of the temperature field is not gradually decreased from the top to the bottom, the length of the temperature field is short, and the lowest temperature in the temperature field is high, and the fiber is annealed. The temperature at the tube is still kept high. However, due to the society's communication requirements for long-distance communication capacity, fiber drawing manufacturers have further optimized the wire drawing process to reduce fiber attenuation. The most fundamental approach is to reduce the internal stress of the fiber to reduce microcracks. Many manufacturers have thought of fully annealing the fiber to reduce internal stress to reduce surface microcracks. There are also some manufacturers that install an annealing furnace under the annealing tube, which has two drawbacks: 1. The installed annealing furnace takes up space. 2. The annealing furnace is heated to waste electrical energy.

Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical fiber drawing annealing apparatus which is energy efficient and allows the fiber to be sufficiently annealed.

In order to achieve the above object, the technical solution adopted by the present invention is: an optical fiber drawing annealing device, comprising a drawing furnace, a fixed annealing tube connected under the drawing furnace, further comprising a sealing connection under the fixed annealing tube for extending a moving annealing tube for annealing the temperature field and a driving portion for driving the moving annealing tube, the moving annealing tube comprising an outer tube, a graphite inner bush fixedly mounted in the outer tube, and being mounted at a lower end of the outer tube a first blowing portion for supplying an inert gas to the moving annealing tube, wherein the first blowing portion includes a casing, a flow guiding block installed in the casing, and the guiding block is provided with the The inert gas supplies the upper and lower flow channels to the upper and lower ends of the moving annealing tube.

Optimized, the driving portion includes a screw driving mechanism including a screw and a screw and a nut on the screw, the driving mechanism further includes a nut connected to the screw mechanism and the The connection between the outer tubes.

Further, the connecting member includes a first link and a second link that are rotatably connected and lockable, and the first link and the second link respectively correspond to the outer tube and the nut The connection is rotated, and the first link and the outer tube, the second link, and the nut are respectively fixed in relative positions by a lock pin.

Preferably, a second blowing portion is disposed under the drawing furnace, and the density of the inert gas blown into the second blowing portion is greater than the density of the inert gas blown into the first blowing portion.

Preferably, the flow rate of the inert gas in the upper flow guiding channel is greater than the flow rate of the inert gas in the lower flow guiding channel.

Preferably, the angle between the upper guiding channel and the axis of the graphite inner liner is 20°-40°.

Preferably, the angle between the lower flow guiding channel and the axis of the graphite inner bushing is 40° to 60°.

Preferably, the bottom cover of the outer casing is provided with a through hole of the optical fiber, and the lower end of the first blowing portion is provided with a shutter for controlling the size of the airflow in the moving annealing tube and the fixed annealing tube, and the shutter comprises rotating with the lower end of the outer casing The valve piece is connected and rotated to adjust the size of the passage through the hole, the rotation axis of the valve piece being perpendicular to the bottom cover.

The present invention also provides an optical fiber produced by the above-described fiber drawing annealing apparatus.

Because of the above technical solutions, the present invention has the following advantages compared with the prior art: the moving annealing tube of the present invention adjusts the position by the driving portion, determines whether to install according to the requirements of various optical fibers, and installs a movement under the fixed annealing tube. The annealing tube can extend the length of the temperature field, and the first blowing portion is disposed under the moving annealing tube, and the density of the inert gas outputted by the first blowing portion is smaller than the density of the inert gas outputted by the second blowing portion, so the first blowing portion The inert gas output from the part can rise upwards in the ascending process until it reaches the nozzle of the drawing furnace to form a uniform temperature field with a uniform temperature and a longer temperature. The rising gas will be simultaneously in the drawing furnace and the fixed annealing tube. The silicon carbide is blown into the exhaust gas collecting plate of the furnace mouth of the drawing furnace. Reducing the internal stress of the fiber to reduce microcracks and finally reducing the fiber attenuation. At the same time, the silicon carbide deposited in the drawing furnace and the annealing nozzle can be collected in the exhaust gas collecting plate of the drawing furnace mouth by the lower blowing air, thereby effectively improving the strength and drawing of the fiber. effectiveness.

DRAWINGS

Figure 1 is a schematic view showing the structure of an annealing device;

Figure 2 is a schematic view showing the structure of the first blowing portion;

Figure 3 is a schematic view showing the structure of the shutter.

Detailed ways

The invention is further described below in conjunction with the embodiments shown in the drawings.

As shown in FIG. 1 , the fiber drawing annealing device comprises a drawing furnace, a fixed annealing tube 5 connected to the lower part of the drawing furnace, and a moving annealing tube 6 sealed and connected under the fixed annealing tube 5 for extending the annealing temperature field, for driving The driving portion on which the moving annealing tube 6 moves is attached to the barometer 7 on the fixed annealing tube 5 and the oxygen analyzer 8 attached to the moving annealing tube.

The moving annealing tube 6 includes an outer tube 12, a graphite inner liner 11 fixedly mounted in the outer tube 12, and a first portion mounted on the lower end portion of the outer tube 12 and supplying an inert gas to the moving annealing tube 6. a blowing portion 9, as shown in FIG. 2, the first blowing portion 9 includes a casing 13 and a flow guiding block 14 mounted in the outer casing 13, and the flow guiding block 14 is provided with the inertia The gas guides the upper and lower flow paths 15 and 16 to the upper and lower ends of the moving annealing tube 6.

a second blowing portion is disposed under the drawing furnace (the drawing furnace and the second blowing portion are both prior art and will not be described herein), and the density of the inert gas blown into the second blowing portion is greater than that of the second blowing portion. The density of the inert gas blown into the blowing portion 9. The flow rate of the inert gas in the upper flow guiding passage 15 is larger than the flow rate of the inert gas in the lower flow guiding passage 16. The angle between the upper guide passage 15 and the axis of the graphite inner liner 11 is 20 to 40. The angle between the lower flow guiding passage 16 and the axis of the graphite inner liner 11 is 40 to 60. In the present embodiment, the upper flow guiding channel 15 and the lower guiding flow channel 16 are respectively formed by a plurality of strips uniformly distributed around the axis of the graphite inner liner 11 , and an outer flow path is formed between the outer casing 13 and the flow guiding block 14 , and The upper flow guiding passage 15 communicates with the lower flow guiding passage 16, and the side wall of the outer casing 13 is provided with an air inlet.

The bottom cover of the outer casing 13 is provided with a through hole of the optical fiber, and the lower end of the first blowing portion 9 is provided with a shutter for controlling the size of the airflow in the moving annealing tube 6 and the fixed annealing tube 5, as shown in FIG. A valve plate 10 is provided that is rotatably coupled to the lower end of the outer casing 13 and that is rotated to adjust the size of the through hole, the shaft of the valve plate 10 being perpendicular to the bottom cover. In the present embodiment, the valve plate 10 has two pieces and is disposed symmetrically. The valve piece 10 is respectively provided with a semicircular notch. After the two valve pieces 10 are closed, the two semicircular notches are closed to form a center through hole.

The drive portion includes a screw drive mechanism including a screw 1 and a threaded connection with a nut 2 on the screw 1, the drive mechanism further comprising a nut 2 and a joint connected to the screw mechanism The connections between the outer tubes 12 are described. The connecting member includes a first link 3 and a second link 4 that are rotatably connected and lockable, the first link 3 and the second link 4 respectively and the outer tube 12 and the The nut 2 is rotationally coupled, and the first link 3 and the outer tube 12, the second link 4, and the nut 2 are respectively fixed in relative positions by a lock pin.

The working principle of the invention is as follows: firstly, the moving annealing tube is sent to the vicinity of the lower portion of the fixed annealing tube by the driving portion, finely adjusted by the connecting member, the moving annealing tube is moved directly under the fixed annealing tube, the connecting member is locked, and then the screw is rotated. The moving annealing tube is driven upward and the fixed annealing tube is sealed and spliced, and then the drawing furnace can start working. At the same time, the second blowing portion and the first blowing portion work to form a uniform and significant cooling temperature, and the length is longer. At the temperature field, the rising gas simultaneously blows the silicon carbide in the drawing furnace and the fixed annealing tube into the exhaust gas collecting plate of the furnace mouth of the drawing furnace. Reducing the internal stress of the fiber, reducing the microcrack, and finally reducing the fiber attenuation. The attenuation of the fiber produced by the above-mentioned wire drawing furnace is low, and the silicon carbide deposited in the drawing furnace and the annealing nozzle can be collected at the wire drawing furnace by the lower blowing. In the exhaust gas collection board, the fiber strength and the drawing efficiency are effectively improved.

The above embodiments are merely illustrative of the technical concept and the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and to implement the present invention, and the scope of the present invention is not limited thereto. Equivalent variations or modifications made in accordance with the spirit of the invention are intended to be included within the scope of the invention.

Claims (9)

An optical fiber drawing annealing device comprising a drawing furnace and a fixed annealing tube connected under the drawing furnace, characterized in that it further comprises a moving annealing tube sealed and connected under the fixed annealing tube for extending the annealing temperature field and using a driving portion for driving the moving annealing tube, the moving annealing tube includes an outer tube, a graphite inner liner fixedly mounted in the outer tube, and is mounted on the lower end portion of the outer tube and is inert to the moving annealing tube a first blowing portion of the gas, the first blowing portion comprising an outer casing, a flow guiding block installed in the outer casing, and the flow guiding block is provided with the inert gas to move the upper end and the lower end of the annealing tube, respectively The upper and lower flow channels are delivered. The fiber drawing annealing device according to claim 1, wherein said driving portion comprises a screw driving mechanism, said screw driving mechanism comprising a screw and a screw connection with a nut on said screw, said driving mechanism further A coupling member between the nut coupled to the screw mechanism and the outer tube is included. The fiber drawing annealing device according to claim 2, wherein said connecting member comprises a first link and a second link that are rotationally coupled and lockable, said first link and said second link The connecting rod is rotatably coupled to the outer tube and the nut, respectively, and the first connecting rod and the outer tube, the second connecting rod and the nut are respectively fixed in relative positions by a locking pin. The optical fiber wire drawing annealing device according to claim 1, wherein a second blowing portion is disposed under the drawing furnace, and the density of the inert gas blown by the second blowing portion is greater than that of the first blowing portion. Inert gas density. The fiber drawing annealing apparatus according to claim 1, wherein a flow rate of the inert gas in the upper flow guiding passage is larger than a flow rate of the inert gas in the lower flow guiding passage. The fiber drawing annealing apparatus according to claim 1, wherein an angle between the upper flow guiding passage and an axis of the graphite inner bushing is 20 to 40. The fiber drawing annealing device according to claim 1, wherein the angle between the lower flow guiding channel and the axis of the graphite inner liner is 40 to 60. The optical fiber wire drawing annealing device according to claim 1, wherein the bottom cover of the outer casing is provided with a through hole of the optical fiber, and the lower end of the first blowing portion is provided for controlling the flow of the air in the moving annealing tube and the fixed annealing tube. a shutter, the shutter comprising a valve piece rotatably coupled to a lower end of the outer casing and configured to adjust a diameter of the through hole, the rotating shaft of the valve plate being perpendicular to the bottom cover. An optical fiber characterized by being produced by the fiber drawing annealing apparatus according to any one of claims 1 to 8.