| 摘要 |
PURPOSE:To obtain a large-sized lamellate glass member which is homogeneous and high viscous by placing a material to be heated that consists of the divided materials of a large-sized high silicic acid glass base material such as a tubular material on a base and heating this in a prescribed furnace. CONSTITUTION:A tubular or a crucible-like large-sized high silicic acid glass base material is divided in the length direction to obtain plural pieces of materials 13 to be heated. These materials 13 to be heated are placed on a base 12 having a smooth surface 12a. Then the base 12 placed with the above- mentioned materials 13 to be heated is introduced into a furnace 1 which is provided with doors 7, 8 for introducing and discharging the base 2, lined with carbon material and provided with introduction ports 4, 5 for nonoxidizing gas. The materials 13 are heated by radiant heat type heaters 3 made of carbon which are arranged to the upper part of the inside of the furnace. |
