| 摘要 |
PURPOSE:To easily and inexpensively produce the titled high-purity quartz tube by using plural multiplex burners, forming a porous layer on the outer periphery of a core material and a porous layer having higher bulk density than the above-mentioned layer thereon, extracting the core material along with the inner porous layer, and sintering and vitrifying the outer porous layer. CONSTITUTION:A quartz rod 3 held by a holder part 1 through a tubular target 2 is rotated and raised, a raw gas and a gaseous fuel are supplied from the multiplex burners 4 and 6, flame hydrolysis is carried out, and the generated soot is deposited. Consequently, the first porous layer 7 having low bulk density is formed on the rod, and the second porous layer 5 having high bulk density is formed on the outer periphery. The first porous layer 7 is extracted along with the quartz rod 3, only the second porous layer 5 is left, and a cylindrical porous base material 8 is obtained. The porous base material 8 is then sintered and vitrified by a heater 9 while being rotated and lowered, and the synthetic quartz tube 10 is obtained. |
