| 摘要 |
A process using a PID software to trigger functions for reducing a He flow in a drawing furnace comprises the following steps: 1. upon heating with a power from zero, sending, by software, a trigger signal, such that a He flow in a furnace reaches 12 L/min; 2. during a speed increase with a drawing speed reaching 1500 m/min, sending, by a software control system, a trigger signal to begin reducing the He flow with a decrement of 0.05 L/min, wherein 80 minutes are required to reduce the He flow to 8 L/min, and adding an Ar flow with the same speed while reducing the He flow, so as to guarantee a constant pressure difference in the furnace; 3. drawing with the helium flow as 8 L/min during normal operation; and 4. upon finishing an entire bar, turning off the furnace, sending, by a PID control system, a control signal to reduce the He flow to 0 L/min, and increasing the Ar gas flow in the same amount while reducing the He flow to prevent external air from entering the furnace. The present application reduces the usage amount of a He flow and a manufacturing cost of optical fibers. |
