| 摘要 |
PURPOSE:To obtain a superior base material for an optical fiber with high efficiency of deposition by introducing an annular flow of gas so that the diameter is gradually reduced toward the top of an oxyhydrogen burner, reducing the diameter of a flame and blowing this flame on a member subjected to deposition. CONSTITUTION:When a flame 300 contg. fine glass particles is jetted from an oxyhydrogen burner 100 such as a multinozzle burner, negative pressure is produced in the region A of an annular path 502 by the high ejection speed of the flame 300 and the open air is smoothly introduced from the rear side of a hood 500 and moved forward as an annular flow of air while gradually reducing the diameter. This annular flow regulates the flow of the flame 300 by its flowing and envelops flame 300 to reduce the diameter of the flame 300. This flame 300 having a reduced diameter is blown on the surface of a member 200 subjected to deposition. |
