Optical fiber perform rod casing tube sintering device, and sintering method thereof

Abstract

The invention discloses an optical fiber perform rod casing tube sintering device. The optical fiber perform rod casing tube sintering device comprises a casing tube, an upper fixing device, a lower fixing device, and a heating furnace; the casing tube is vertically arranged in the heating furnace via the upper fixing device and the lower fixing device; an optical fiber perform rod loose body is arranged in the casing tube, and is connected with the upper fixing device; an air exhausting mechanism is arranged on the upper fixing device; the air exhausting mechanism is connected with an exhaust system and a vacuum pump via a valve switch; and an air intake mechanism is arranged on the lower fixing device. The invention also provides a sintering method. According to the sintering method, casing tube vacuum pumping is adopted for sintering of the optical fiber perform rod loose body, so that application of a furnace core tube which is expensive and is easy to be damaged is avoided, and loose bodies with large sizes can be prepared; at the same time, vacuum environment is beneficial for improving perform rod quality, accelerating sintering speed, and increasing production efficiency; and in addition, furnace core tube-free sintering method is adopted, so that production cost is reduced, equipment complex degree is reduced, and equipment space occupied degree is reduced.

Description

technical field [0001] The invention relates to the field of optical fiber preform manufacturing, in particular to a sintering device and a sintering method for an optical fiber preform casing. Background technique [0002] The large-scale optical fiber preform production process in this field mainly forms loose bodies through VAD and OVD process deposition. The so-called VAD and OVD processes are to make preforms by vapor deposition. Production of SiO in the combustion chamber by introducing the raw material into the flame 2 Granular body, and deposited on the preset target target rod or rod to make a loose body. After the loose body is made by VAD and OVD processes, it is placed in a sintering furnace and sintered at high temperature to form a vitrified preform. The finished preform is drawn to obtain a finished optical fiber, or a quartz sleeve of the same grade as the optical fiber material is used to shrink and outsource it to manufacture a larger-sized optical fiber...

AI Technical Summary

Problems solved by technology

In addition, when the loose body is placed into the furnace core tube from the atmospheric environment, oxygen will inevitably enter into it, and long-term use will inevitably lead to the aging of the furnace core tube and affect product performance

[0013] Another crucial deficiency is that due to the limitations of the materials of the quartz tube itself such as quartz and carbon, the traditional process method generally fixes the furnace core tube and the heating zone and uses the loose body to pass through the heating zone to complete the process. sintering

As a result, the length of the furnace core tube is generally greater than twice the length of the loose body

Obviously, this not only greatly increases the complexity of the equipment and the space occupied by the equipment, but also greatly increases the amount of various process gases, especially those that are very expensive and non-renewable resources, in order to achieve optimal dehydration and completely transparent atmosphere conditions. The amount of helium used, which greatly increases the manufacturing cost of the optical fiber preform

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