FURNACE AND METHOD FOR OPTICAL FIBER WIRE DRAWING

摘要

A furnace for optical fiber wire drawing provided with a core tube (10) and flame tubes (5, 5') connected to the upper end of the core tube, wherein an optical fiber base metal (1) supported by a dummy rod (2) at the upper part thereof is disposed inside the core tube (10) and flame tubes (5, 5') so as to be movable downward together with the dummy rod (2), the optical fiber base metal (1) is heated and melted by a heater (11) from the outside of the core tube (10) and an optical fiber (1a) is pulled out from the lower end of the optical fiber base metal (1); the furnace is further provided with one or a plurality of sets of partition plates (4, 17) adapted to partition a space in the flame tubes (5, 5') above the base metal (1) into a plurality of portions in the advance direction of the base metal and disposed in the space, and with gas blowing ports (8) disposed in the parts of wall surfaces of the flame tubes (5, 5') which are below the partition plates (4, 17) and adapted to blow an inactive gas into the flame tubes (5, 5') and the core tube (10), thereby preventing variations in a wire diameter of the optical fiber (1a).