| 摘要 |
PURPOSE:To enable the automatic feeding of a glass raw material to smelting crucible from outside without causing the contamination, by forwarding a feed pipe to feed the glass raw material to the smelting crucible, and retreating the pipe after feeding, thereby feeding a definite amount of grass raw material intermittently to the crucible. CONSTITUTION:The pinch cock 30 is opened to connect the hopper 28 with the quartz pipe 20. The cock 29 is opened to introduce a highly pure nitrogen gas having low dew point and to supply the nitrogen gas through the hopper 28, the silicone tube 31, the quartz pipe 20, the silicone tube 21 and the quartz pipe 16 into the chamber 3. The feed of a glass raw material is carried out parallel to the feed of the nitrogen gas. When a definite amount of glass raw material is charged to the smelting crucible 5, the upper frame 10 and the feed pipe 16 are retreated without delay. Simultaneous to the end of the operation to feed a definite amount of the glass raw material, the motor 23 and the vibrators 15, 26 are stopped to prevent the fall of the glass raw material out of the crucible 5. Definite amount of the glass raw material can be fed intermittently to the crucible by this process. |
