PRETREATMENT OF POWDER TO BE BLOWN IN TO BLAST FURNACE

摘要

PURPOSE:To maintain the stable supply rate of the powder to a device for blowing the powder into a blast furnace by adjusting the amt. of the combustion gas in a heat generating furnace in accordance with a mill outlet temp. for the moisture fluctuation of a pulverous powder raw material which is fed out at a specified rate and is pulverized by a pulverizing mill. CONSTITUTION:The burner of a hot air generating furnace 7 is ignited while a blower 8 is started in an installation for producing pulverized coal. The temp. is increased up to the temp. necessary for drying of coal (about 200 deg.C at the mill inlet and 90 deg.C at a bag outlet) necessary for drying of coal and the operation is executed only under the control 12 of the mill inlet temp. during this time. The temp. control of the bag outlet 20 or mill outlet 19 is cascaded after the temp. near the above-mentioned temp. is attained and thereafter the control method of this invention is started. The charging of the coal is started where the stability is attained. The charging rate thereof is freely set by the number of revolution of a conveyor 2 for feeding the material at a constant rate to the pulverizing mill 3 so that the substantial follow-up with this control is accomplished even when the setting of the feeding changes. The stable pretreatment of the pulverized powder to be blown to the blast furnace is thus executed.