Induction Heating for Fiber Optics
Drawing furnaces are used to heat pre-formed quartz with a maximum diameter of 80 mm to a temperature of 2,200°C followed by a continuous drawing process to produce fiber optics at speeds of up to and exceeding approximately 4,000ft/minute. Indirect induction heating is applied using a graphite susceptor, which enables precise control of furnace temperature.
In order to protect the fiber, and prevent the graphite crucible from igniting, a neutral gas atmosphere such as Argon is maintained in the chamber and thermal inertia is reduced to a minimum. The power consumed by the transistorized power supply lies generally between 25 & 50 kW at a nominal operating frequency of approximately 15 kHz.