| 摘要 |
PROBLEM TO BE SOLVED: To prevent the contamination of a soot preform at a low cost by surrounding the soot preform with a shielding member having a specific structure and being capable of freely extending and contracting, and transporting while supplying an inert gas in the shielding member at the time of transporting the soot preform to the forming process and the succeeding dehydrating and sintering process. SOLUTION: At the time of transporting the soot preform to the forming process and the dehydrating and sintering process, the following means is used. The shielding member 1 capable of freely extending and contracting and covering the upper part of a chamber (reaction chamber) 7 while extending with the formation of the soot preform 6 is fitted. The transportation of the soot preform to the dehydrating and sintering process is executed while supplying a cleaned gas (e.g. gaseous nitrogen) in the shielding member 1 from a communicating pipe 20. |
