| 摘要 |
PURPOSE:To improve the formation efficiency of glass fine particles when subjecting a gaseous starting material to flame hydrolysis in a flame to form glass fine particles and producing an optical fiber porous base material by giving pressure fluctuation to the flame from its inside. CONSTITUTION:The base end of a gas feeding pipe installed in a burner 7 is extended to provide an extension pipe part 4, and a terminal-expanded taper pipe 19 is connected to the base end of the extension pipe part 4. A speaker 21 as a pressure fluctuation generating means is connected to the base end of the taper pipe 19 through an elastic plate 20, and an oscillator 22 is connected to the speaker 21. A gaseous starting material such as SiCl4 and gaseous H2, O2 or the like are fed to the burner 17 from gas feeding pipes 15, 16, 17..., and the SiCl4 is hydrolyzed in the formed oxygen-hydrogen flame 8 to form glass fine particles, which are stuck to a starting member 2 to produce an optical fiber base material 9. At the same time, pressure fluctuation is given to the flame 8 by the speaker 21 from its inside to efficiently accelerate the diffusion mixing of the gaseous starting material such as SiCl4 with fuel gas such as gaseous H2, O2 or the like. |
