KÜHLUNG VON OPTISCHEN FASERN

摘要

Hot optical fibre being drawn from a preform is cooled in a helium cooled heat exchanger by a two-stage process. In the first stage, in which the rate of draw of fibre through the heat exchanger is increased to the design draw rate, the rate of flow of helium to the heat exchanger is increased as the rate of draw of fibre is increased. Helium is withdrawn from the heat exchanger by a variable speed blower, and during the first stage the rate of withdrawal of helium from the heat exchanger is controlled primarily by the rate of flow of helium into the heat exchanger, and during the second stage, the rate of flow of helium to the heat exchanger is maintained constant and the rate of withdrawal is determined primarily by the pressure in the heat exchanger.