STEEL STRIP CONTINUOUS ANNEALING FURNACE, STEEL STRIP CONTINUOUS ANNEALING METHOD, CONTINUOUS HOT-DIP GALVANIZATION EQUIPMENT, AND PRODUCTION METHOD FOR HOT-DIP GALVANIZED STEEL STRIP

摘要

Provided is a continuous annealing furnace in which the dew point of furnace atmosphere can be rapidly lowered to a level suitable for normal operation and in which atmosphere having a low dew point, which is less likely to cause pick-up defects and damages to furnace walls, is consistently achieved. Also provided is a method for continuously annealing a steel strip using the annealing furnace. A continuous annealing furnace for annealing steel strips that is a vertical-type annealing furnace configured so that part of gas inside the furnace is drawn and introduced to a refiner disposed outside the furnace including an oxygen removing apparatus and a dehumidifying apparatus, oxygen and moisture contained in the gas are removed to lower the dew point of the gas, and the gas having a lowered dew point is put back into the furnace. At least one gas inlet through which gas is drawn from the furnace into the refiner is disposed in the vicinity of the entry side of the furnace at a distance of 6 m or less in the vertical direction and 3 m or less in the furnace-length direction from the steel-strip-introduction section located at the lower part of the heating zone.