GAS WIPING METHOD AND APPARATUS USING EXHAUST GAS FROM NONOXIDATION FURNACE

摘要

PURPOSE:To save energy and enhance the quality of hot dipping by sucking exhaust gas from a nonoxidation furnace and spraying it on the surface of a steel strip sent out of a molten metal bath after raising the gas pressure. CONSTITUTION:Exhaust gas from nonoxidation furnace 1 in the hot dipping line is sucked with exhaust fan 5 through heat exchanger 4. At this time, in order to prevent unfavorable influence from being exerted on the atmosphere in furnace 1 owing to an abnormal drop in the internal pressure of furnace 1 by the suction of fan 5, pressure regulating valve 9 is automatically regulated in accordance with a detected signal from pressure detector 8. The gas from fan 5 is then raised in pressure and temp. with high temp. blower 7. This gas is sprayed from nozzles 2 of the gas wiping unit on steel strip S sent out of the molten metal bath to make the hot dipping thickness uniform. The spraying pressure is detected with pressure detector 10, and delivery pressure regulating valve 11 is controlled so that exhaust gas of a predetermined pressure is sprayed from nozzles 2 by a predetermined vol.