PURPOSE: To shorten the time of switching an air blower as well as lessen the loss of power during the switching period by a method in which the regulation of the moisture content of air blown into a blast furnace is made while gradually intensifying forced humidification to the dehumidified air prior to the beginning of switching the air blower and the moisture content of air blown into blast furnace is regulated to much the same one as that of the open air when the air blower is to be switched.
CONSTITUTION: A humidifier 11 and a hygrometer 12 are placed in a cold air tube 10. Prior to the beginning of switching an air blower 1 to an air blower 2, the moisture content of air is regulated to much the same one as that of the open air with a given speed by means of a humidifier 11 in a varying range enough not to change the operation of a blast furnace 16. Then, the moisture content of air blown into the blast furnace 16 is controlled in such a way as to nearly equalize the moisture content with that of the open air by regulating a variation in the moisture content of air due to the reduction of the amount of dehumidified air from the air blower 1 by means of the valve of the humidifier 11 on the basis of the detected value of the hygrometer 12. The switching of the air blower during the period is performed only by valves 4, 6, 3, and 5, and therefore, the switching can be completed in a short time. In the figure, 9 is a dehumidifier provided on the suction side of the air blower 1.
KIKUCHI KAZUNARI
TAKABE RIYOUJI
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