METHOD FOR JUDGING INACTIVITY OF HEARTH IN BELLESS BLAST FURNACE

摘要

PURPOSE: A method for judging inactivity of hearth in a belless blast furnace is provided to judge the extent of inactivation of the hearth by calculating an inactivation index based on temperature per portions of the furnace body detected from furnace body thermometers inserted into bricks of the hearth of the blast furnace. CONSTITUTION: The method for judging inactivity of hearth in a belless blast furnace(10) comprises the steps of periodically measuring temperature of the hearth of the blast furnace from thermometers (T1,T2,T3) a plural of which are arranged in a circumferential direction of the body of the blast furnace and installed in multistage in a height direction thereof; judging the state of hearth of the blast furnace as the initial inactivation state if an average temperature value of all temperature values measured from the thermometers is 70 deg.C or less; and judging the state of hearth of the blast furnace as the inactivation continuation state if 5 days or more are lasted in the state that an average temperature value measured from two-stage thermometers selected from the thermometers installed in multistage is 60 deg.C or less, or if 5 days or more are lasted in the state that temperature values measured from 75% or more of thermometers in the selected two-stage thermometers are 50 deg.C or less with temperature deviation of the measured temperature values being within ±2 deg.C.