| 摘要 |
PURPOSE:To convert a formed body of glass oxide powder into transparent glass while reducing the consumption of inert gas by circulating atmospheric gas contg. inert gas through the inside and outside of a heating region enclosed by a container or the like and by heat treating the formed body in the heating region. CONSTITUTION:A formed body 12 of glass oxide powder supported by a rotary rod 13 is rotated through the rod 13 in a heating region 2, and in this state it is converted into transparent glass by heating to a high temp. with a heating furnace 1. At this time, the atmospheric gas 3 in the region 2 is circulated through the inside and outside of the region 2 with a blower 5 through a gas chamber 6 and a circulation path 4. Since this circulation system is not perfectly airtight, air is contained, so the O2 concn. of the atmospheric gas is detected with a gas concn. detector 10, and by opening or closing a magnet valve 7 through an amplifier 11, the introduction of inert gas from a gas cylinder 9 is controlled so as to keep the concn. within a prescribed range. |
