Device and method for manufacturing optical fiber preform rod by using OVD technology

Abstract

The invention relates to a device and a method for manufacturing an optical fiber preform rod by using an OVD technology. The device comprises a deposition cavity, wherein the top part and the lower part of the deposition cavity are correspondingly provided with upper and lower synchronously-rotating chucks which are used for clamping to-be-sprayed core rod; equidistantly-spaced blast lamp assemblies, corresponding to the upper and lower synchronously-rotating chucks, are vertically arranged at one side of the deposition cavity and connected with a slide seat which moves up and down; and an air suction opening, corresponding to the blast lamp assemblies, is arranged at the other side of the deposition cavity. The device is characterized in that a laser diameter measurer is arranged at theouter side of the deposition cavity; the output end of the laser diameter measurer is connected with a PLC; the control end of the PLC and a chuck rotation control system are connected to realize real-time feedback regulation and control of the outer diameter of a powder rod and the rotating speed of the rotating chucks; thus, linear velocity at the intersection position of a powder rod depositionsurface and a flame center drop point remains constant in the whole process of deposition. The device and the method provided by the invention can improve the overall uniformity and collection rate of the powder rod, and improves the OVD manufacturing efficiency and quality of the powder rod; and a feedback device provided by the invention is simple and reliable, can be easily implemented, has strong stability, and is applicable to mass production.

Description

technical field [0001] The invention relates to an OVD device and method for manufacturing an optical fiber preform, belonging to the technical field of optical fiber manufacturing. Background technique [0002] In the current mainstream optical fiber preform technology, VAD technology is used to make the core rod, and the combination of OVD technology to make the outer cladding of the core rod is beneficial to reduce the cost of the optical fiber base material preform, so it has been the direction of technical efforts for major optical fiber manufacturers. The raw material used in the OVD external injection technology of the mandrel is generally silicon tetrachloride, which undergoes a hydrolysis reaction under the action of an oxygen-hydrogen flame to produce silicon dioxide as the main product, and silicon dioxide will decompose within a certain temperature gradient range. A heat surge effect occurs, so it accumulates on the surface of the rod. [0003] As the deposition...

AI Technical Summary

Problems solved by technology

[0003] As the deposition continues, the outer diameter of the powder rod will gradually become thicker. If the rotational speed remains constant, the linear velocity at the junction point between the flame and the surface of the powder rod will gradually increase as the outer diameter becomes thicker. The linear velocity at the junction point between the flame and the surface of the powder rod will be much faster than that at the junction point between the flame and the surface of the powder rod with a thin outer diameter. As the outer diameter of the powder rod becomes larger, the difference will be greater; Faster speed means that the time for the surface of the powder rod to stay in the flame wrap is shortened, resulting in an unstable deposition temperature between layers and a large difference in density, which is likely to cause production instability such as deposition cracking and lower collection rate. It will get lower and lower, and the overall uniformity of the powder stick is not good

Images