Dual control in the last stage of oxygen injection in the converter

An algorithm is proposed for dual control, in which identification of the model of change in oxygen flow rate during injection—in particular, change in CO content in the converter’s exhaust gases—is accompanied by correction of the oxygen flow rate in the final stages of the melt. In this algorithm, a stepped control signal is applied at a specified time and monitored during the following interval. The control signal and output signal are recorded during the transient process and those data provide the basis for refinement of the coefficients employed in the model and refinement of the control signal. The calculated control signal is employed in the next control interval. The effectiveness of the proposed control algorithm is estimated in terms of the smoothness of the time series for the carbon content in the metal at the singular point and the consistency of the steel’s carbon content at converter discharge.