PURPOSE: To prevent the overheating of a receiving ironware by providing an opening to the shell at the part of a regenerator where the checker brick receiving ironware is present and furnishing a riser with the end opened closer to a hot air stove than the hot air valve of a hot air pipe.
CONSTITUTION: Plural openings 1 are provided on the shell of a regenerator 45 at its lower end where a checker brick is present, and a riser 3 having a shutoff valve 2 and with its end opened is provided closer to the hot air stove than the hot air valve 37 of a main hot air pipe 36. When a blast furnace is repaired, the hot air pipe 36 to the furnace is closed by the valve 37 from the blowing down of the furnace to the time to start ore feeding, and hot air is discharged or not supplied. In such a case, a combustion gas is generated in a combustion chamber 31 and supplied to the regenerator 45, when the temp. of the regenerator 45 is decreased below a specified temp. (about 600°C). When the temp. of a regenerator 45 reaches the upper limit of the specified control temp., the generation of the combustion gas is stopped, the valve 43 of a flue 42 is closed, the openings 1 are opened, the shutoff valve 2 of the riser 3 is opened, cold air is passed through the regenerator 45 and combustion chamber 31, and a decrease in the strength of the receiving ironware due to high temp. is prevented.
KISHIMOTO SUMIYUKI
WATANABE KOICHI
