METHOD AND DEVICE FOR CONTROLLING TEMPERATURE OF COOLING FURNACE FOR CONTINUOUS ANNEALING INSTALLATION

摘要

PURPOSE:To enable control of the final cooling temp. to a pescribed value as far as possible and to improve yield by compensating the low responsiveness of the winding angle on a roll or refrigerant temp. with the flow rate of a cooling gas having high responsiveness. CONSTITUTION:A gas jet cooler II which cools a strip 7 by blowing a cooling gas to the strip 7 and a roll cooler I which cools the strip 7 by bringing the strip 7 into contact with the outside circumferential surface of cooling rolls 9a-e passed internally with a refrigerant are combined. The final cooling temp. of the strip 7 is controlled so as to attain a set value by operating the flow rate of the cooling gas in the cooler II and the contact length of the strip 7 with the rolls 9a-e in the cooler I or the refrigerant temp. The contact length of the referigerant temp. under over-responsiveness is detected and the cooler II is so controlled as to compensate the lack of cooling with the rolls 9a-c occuring in the low responsiveness on the basis of the detected value in the stage of changing the contact length or refrigerant temp. in the cooler I from the set value to other set value.