GLASS OUTFLOW DEVICE, GLASS OUTFLOW METHOD, METHOD FOR MANUFACTURING GLASS MOLDING AND METHOD FOR MANUFACTURING OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for flowing out a molten glass material having volatility from a pipe to manufacture a preform, capable of preventing a stria from occurring in the preform.SOLUTION: A glass outflow device 1 for flowing out a molten glass comprises: an outflow pipe 4 extended in a vertical direction and flowing out the molten glass; an induction heating coil 6 provided on the outer peripheral side of the outflow pipe 4; and a loop member 14 provided so as to surround the outside of the outflow pipe 4 in a horizontal view and consisting of a closed loop shaped conductor allowing induction heating by the induction heating coil 6.