| 摘要 |
PURPOSE:To prevent clogging of a discharge pipe by excessive reaction product and to proceed reaction smoothly to cause a reaction in a reaction vessel by providing many small holes to discharge pipe for excessive reaction product fitted to the reaction vessel and ejecting gas from the pipe. CONSTITUTION:A seed bar 3 is suspended in a reaction vessel 1 and gaseous raw material is ejected from the bottom through an oxyhydrogen burner 2 and base material for optical fiber 4 is deposited to the tip of the seed bar 3 by causing flame hydrolysis. The excessive reaction product in the furnace is discharged from a discharge passage 5; many ejection holes 14 for gas are provided to the gas ejection pipe 12. The gas is fed from a gas feeding port 13 and ejected into the inside of the gas discharge pipe 12. The excessive reaction product is discharged together with the gas preventing clogging of the gas discharge pipe 12 due to deposition of the product on the inside surface of the gas discharge pipe 12. By this way, reaction conditions in the reaction vessel 1 are held always constant and variation of quality (distribution of refractive index) of the base material 4 is prevented. |
