| 摘要 |
PURPOSE:A mixture of 2 or more different kinds of combustible gases is used as a flame-burning gas for synthesizing fine glass particles to enable high-speed production of the titled parent material, avoiding reduction in the deposition efficiency of fine glass particles. CONSTITUTION:Fine glass particles are synthesized in the flame flow so that the particles are deposited in the axis direction to form a porous parent material 1, then the material is heated and sintered at high temperatures to give a clear parent material for optical glass fibers. At this time, a mixed gas of 2 or more different kinds of combustible gases such as hydrogen, methane or propane is used as a flame-burning gas for synthesis of fine glass particles from, e.g., SiCl4+GeCl4. For example, a mixed gas of methane and hydrogen, as its mixing ratio is controlled by means of flow meters 3, 4, respectively and fed together with oxygen gas and the starting gas for glass to the synthesis torch 2 to form a flame and fine glass particles. |
