METHOD FOR CONTROLLING STRIP LOOP IN CONTINUOUS ANNEALING FURNACE

摘要

PURPOSE: A method for controlling strip loop in the continuous annealing furnace is provided to remove the strip loop supplied into the annealing furnace when continuous annealing line through which strip passes is stopped by abnormality of the annealing furnace so that the annealing furnace is restarted. CONSTITUTION: In a strip loop control method for removing strip loop existed in the annealing furnace by reversely driving a driving motor for driving strip threading driving roll at first driving speed before restarting annealing furnace after continuous annealing line is stopped, thereby storing strip into looper tower, the method for controlling the strip loop in annealing furnace comprises the steps of setting up a reference tension allowable by the driving roll when threading the strip into the annealing furnace; stopping the driving motor after initially reversely driving the driving motor at the first driving speed for a certain set period of time; measuring tension impressed to the driving roll as reversely driving the stopped driving motor again at the first driving speed; lowering driving speed of the driving motor to second driving speed when measured tension of the driving roll is 30% or more of the reference tension; and stopping the driving motor when measured tension impressed to the driving roll is 50% or more of the reference tension while the driving motor is reversely being driven at the second driving speed.