Cooling method using a gas jet cooling device

摘要

A gas jet cooling device in a continuous annealing furnace is equipped with: windboxes disposed in a cooling chamber on both sides of a steel strip, blowing a cooling gas toward the strip through nozzles to cool it; and a means of cooling the gas introduced from the cooling chamber and then supplying the cooled gas to the windboxes, wherein the distance between the tips of the nozzles and the strip is not more than ten times the diameter of the nozzles; and the length of each of the windboxes in the strip traveling direction is not more than two thirds of the width of the strip. The gas jet cooling device can cool the strip rapidly and uniformly even when the distance between the strip and the front face of each windbox is shorter and the size of a cooling chamber is smaller than the conventional ones.