| 摘要 |
The foams during vacuum refining of glass are collapsed by depositing on its surface substance e.g. water, alkali metal cpds. or solns.; esp. sodium hydroxide or carbonate. The refining chamber is at below 0.5 atm. and esp. is no more than 100 torr. The substance is liq. when fed into chamber. For soda-line-silica glass, refining is with addn. of 2 pts. wt. Na sulphate per 1000 pt. wt. silica source material, or is esp. with sulphate absent. The substances are suppiled continuously or incontinuously. |
