METHOD FOR CONTROLLING TEMPERATURE OF CONTINUOUS HEAT TREATMENT FURNACE FOR STEEL STRIP

• Main Author: KUNIKATA YASUO
• Format: Patent
• Language: English
• Published: 25.12.2008
• Subjects: CHEMISTRY; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS

PROBLEM TO BE SOLVED: To provide a method for controlling the temperature of a continuous heat treatment furnace by which the most suitable cooling can be obtained while avoiding the insufficient cooling and the over-cooling when changing an operational condition in a slow cooling zone of the continuous heat treatment furnace for steel strip. SOLUTION: In the temperature control method of the continuous heat treatment furnace for steel strip, by which the rear end part of a front steel strip 11 and the front end part of a rear steel strip 12, are welded to form a continuous steel strip 13, and the continuous steel strip 13 is heated while passing through a heating zone in the continuous heat treatment furnace for steel strip and slow-cooled while passing through a slow cooling zone 15 blowing the cooling blast with a blower 14; at the time of steady-state operation, in which the change of the furnace temperature with a heater 16 arranged in the slow cooling zone 15 and the change of the rotation number of the blower deciding the total blasting amount blown in the slow cooling zone 15, are not performed, the adjustment of the strip temperature in the slow cooling zone 15 is performed with a feedback control, and in the other side, at the time of changing the operational condition for changing only the rotation number of the blower and the furnace temperature in the slow cooling zone 15, the feedback control is interrupted and the rotation number of the blower or the furnace temperature in the slow cooling zone 15 is performed with the feed-foreward control. COPYRIGHT: (C)2009,JPO&INPIT