Methods and systems for controlling air flow through an annealing furnace during optical fiber production

A method of inducing gas flow in an annealing furnace, the method comprising:

• translating an optical fiber within an annealing furnace along a draw pathway, the annealing furnace comprising:
• a furnace inlet;
• a furnace outlet;
• and
• a process tube extending between the furnace inlet and the furnace outlet, the process tube comprising a process tube wall and a plurality of heating zones, each heating zone comprising at least one heating element;
• and
• inducing a gas flow from a gas distribution assembly fluidly coupled to the furnace outlet into the process tube, the gas flow flowing within the process tube in an upflow direction.

An optical fiber production system comprising:

• a draw furnace configured to draw an optical fiber from an optical fiber perform along a draw pathway extending from the draw furnace;
• an annealing furnace positioned along the draw pathway, wherein the annealing furnace comprises
• a furnace inlet;
• a furnace outlet;
• and
• a process tube extending between the furnace inlet and the furnace outlet, the process tube comprising a process tube wall and a plurality of heating zones, each heating zone comprising at least one heating element;
• a gas distribution assembly positioned along the draw pathway and fluidly coupled to the furnace outlet and structurally configured to induce a gas flow from the gas distribution assembly into the process tube such that the gas flow within the process tube is in an upflow direction, wherein the annealing furnace is positioned between the draw furnace and the gas distribution assembly;
• and
• a fiber collection unit positioned along the draw pathway, wherein the gas distribution assembly is positioned between the annealing furnace and the fiber collection unit.