| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical fiber cooling device that cools an optical fiber while being drawn and that can prevent a cooling gas from leaking from a lower side of the optical fiber cooling device as much as possible.SOLUTION: An optical fiber cooling device 20 sets A, "k", and C within ranges satisfying A-B-kC≤0 holds, where A presents lower gauge pressure of a cooling pipe part 21 of the cooling device 20, Li (i=1 to N) represents a length of each division unit, Ri (i=1 to N) represents a radius of each division unit, Qi (i=1 to N) represents a gas flow rate of a cooling gas G3,μ1 represents a viscosity coefficient, r1 represents a radius of an optical fiber, V1 represents a fiber drawing speed, B represents pressure loss of a straight pipe part 22, LLj (j=1 to n) represents a length of each division unit, RRj (j=1 to n) represents a radius each division unit, Qrepresents a gas flow rate of pressure gas,μ2 represents a viscosity coefficient, C represents pressure loss of a pressure chamber 23, D1 to D5 represent internal pressure correlation constants, and "k" (1≤k≤2) represents a shape correction coefficient.</p> |
