METHOD AND APPARATUS FOR PRODUCING PREFORM FOR OPTICAL FIBER

摘要

PURPOSE:To efficiently produce a glass fine particle-stacked body as an intermediate product for an optical fiber. CONSTITUTION:A reaction vessel 12 is provided in it with a glass fine particles- producing burner 1 and a gas-exhausting apparatus having plural exhaust holes 8 continuously placed along a rotating starting rod 3 and shafts for supporting the starting rod. In this system, the glass fine particles-producing burner 1 is supplied with a gaseous raw material for glass, a fuel gas and an auxiliary gas. Glass fine particles are produced by flame hydrolysis or oxidation and they are stacked on the periphery of the rotating starting rod 3. During this process, the glass fine particle-producing burner 1 is transferred in the axial direction of the starting rod 3 and the glass fine particles are evenly stacked on the periphery of the starting rod 3 as the stacked body 4 to produce the objective optical-fiber preform. Further, the amount of exhaust of each exhaust holes 8 is varied in serial order in accordance with the transferring of the glass fine particles-producing burner 1 along the starting rod 3.