| 摘要 |
PURPOSE:To shorten treatment time by lining a quarts glass pipe and constituting a core pipe with a ceramic cylinder as an outer wall. CONSTITUTION:A quarts glass pipe 11 is lined while a ceramic cylinder 12 is arranged to be an outer wall, thereby forming a core pipe 1. A heater 2 is laid out is such a fashion that it may envelop the core pipe 1 while an insulation material 3 is further laid out in such a fashion that it may envelop the heater 2. Since the quarts glass pipe 11 is used for the inner-lining of the core pipe 1, the property of cleanses is maintained. In addition, the ceramic cylinder 12 is used as the outer wall of the core pipe 1, which provides strength during heating operation at high temperature to a satisfactory extent so that excellent pressure resistant properties may be available. This construction makes it possible to increase the pressure of helium gas for enhanced treatment with higher efficiency and reduce treatment time as well when carrying out caking/ transparent glass formation and dehydration treatment of soot preforms 4. |
