METHOD FOR DEFOAMING MOLTEN GLASS UNDER REDUCED PRESSURE AND APPARATUS FOR PRODUCING GLASS USING DEFOAMING UNDER REDUCED PRESSURE

摘要

A method for defoaming a molten glass under a reduced pressure which comprises storing a molten glass obtained by melting a raw material in a melting vessel; allowing the molten glass to flow upward into a vacuum defoamation vessel, whose interior is under a reduced pressure, via an introduction pipe by suction; deforming the molten glass in the vacuum defoamation vessel; and then allowing the resultant deformed molten glass to flow down to thereby discharge it via a discharging pipe; characterized in that the above defoamed molten glass is allowed to flow down to a level of height direction which is lower than that of the bottom of the melting vessel.