Optical fiber annealing extension tube used for high-speed drawing

Abstract

The invention relates to an optical fiber annealing extension tube used for high-speed drawing. The optical fiber annealing extension tube comprises a metal tube, a glass tube and an air sealing mechanism, wherein the metal tube is fixedly connected with a drawing furnace; the glass tube is detachably connected with the lower end of the metal tube; the air sealing mechanism is arranged at the lower end of the metal tube and basically seals an opening at the lower end of the metal tube after being separated from the glass tube and connected with the metal tube; and the glass tube has a vacuum dual-layer structure. The annealing extension tube adopts a mode that the metal tube and the glass tube are arranged sectionally and detachably; when the glass tube needs to be washed, the metal tube only needs to be detached from the lower part of the metal tube so that the length of the glass tube can be extended as required; therefore, the high-speed drawing is ensured. By adopting the vacuum dual-layer structure, heat loss in the extension tube can be prevented effectively so as to improve the optical fiber warping degree; and the optical fiber annealing extension tube has great popularization and application values.

Description

technical field [0001] The invention relates to an optical fiber annealing extension tube used in the optical fiber drawing process. Background technique [0002] The fiber annealing extension tube is a section of extension tube set under the drawing furnace to prevent the fiber from being quenched and affecting its performance after the fiber is drawn out. The extension tube mainly affects fiber attenuation, cladding out-of-roundness and fiber warpage. Wherein, the warpage refers to the radius of curvature corresponding to the bending of the bare optical fiber without any external stress. The main reasons that affect the warpage are: 1. The fiber is heated unevenly in the temperature field, resulting in uneven shrinkage of the fiber in the neck direction; 2. The fiber is quenched after it comes out of the drawing furnace, resulting in an increase in the internal stress of the fiber. [0003] However, under high-speed drawing, the warpage of the optical fiber will deterior...

AI Technical Summary

Problems solved by technology

However, this kind of optical fiber annealing device is only suitable for low-speed drawing below 1500m / min, and the length of the extension tube can only reach 1.2m. When the fiber speed is increased to 1800m / min or even 2000m / min, the extension tube under the drawing furnace will be as long as If the existing glass extension tube is still set in the metal tube, due to the limitation of the operation site, it will be difficult to take out such a length of extension tube from the metal tube. This application is developed based on the above background design

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