| 摘要 |
PURPOSE:To produce the optical fiber base material having stable characteristics in an axial direction by generating always stable air flow within a deposition box regardless of the degree of growth of soot. CONSTITUTION:Wind velocity sensors 6 are provided at plural points in the deposition box 1 and the flow of the air in this box is three-dimensionally analyzed by an air flow analyzer 7. The results thereof are sent to a clean air controller 2. This clean air controller has blow-off ports 3 having a two-dimensional spread and can control the quantity of the air blown off at the respective points of the blow-off ports 3. As a result, the air flow can be scrupulously controlled at each position according to a change in the soot shape even if the soot shape changes according to the growth thereof and, therefore, the always stable air flow is formed within the deposition box regardless of the change in the soot shape. |
