INTRODUCING AIR CONTROL DEVICE FOR METALLIC OXIDE REDUCING FURNACE

摘要

PROBLEM TO BE SOLVED: To provide an introducing air control device for a metallic oxide reducing furnace excellent in the stability as well as the response property of control and capable of continuing the operation of the same even upon abnormality of oxygen concentration. SOLUTION: An introducing air flow rate SA is determined by adding a regulating value A, given from an oxygen concentration control system, to a necessary air reference flow amount RA obtained employing the charging amount or the like of pellets whereby an introducing air flow amount control employing the necessary air reference flow amount RA as a feedforward value is carried out. Accordingly, the introducing air flow amount SA is determined from the necessary air reference flow amount RA and the regulating value A, which are fluctuated in accordance with the fluctuation, whereby the response property of the control can be improved without accompanying the deterioration of stability compared with a case when the introducing air flow amount SA is determined by only a feedback control employing the measured value of an oxygen concentration analyzer. Further, the regulating value A is controlled so as to be zero upon the abnormality of an oxygen sensor whereby the necessary air reference flow amount RA is determined as the introducing air flow amount SA as it is.