| 摘要 |
PROBLEM TO BE SOLVED: To provide an upper seal structure and a sealing method for an apparatus for manufacturing an optical fiber preform which inhibits an intrusion of an atmospheric air into a reaction chamber through a gap around a shaft in manufacturing an optical fiber preform by the VAD method. SOLUTION: In an apparatus for manufacturing an optical fiber preform having an reaction chamber 1 to deposit glass microparticles formed by a flame reaction of a raw material gas at a starting member installed at the tip of a shaft 3 and an upper chamber 2 set on the reaction chamber 1 where a deposited porous optical fiber preform is pulled and stored, a separable lid 5 is installed on the top opening of the upper chamber. The lid 5 has a hole 6 to insert a shaft 3 at its center, a divided space and an inlet of a clean gas 9, which has a structure to flow out the clean gas introduced into the lid along the shaft 3 from the space inside the lid to both the reaction chamber and the outside. COPYRIGHT: (C)2003,JPO |
