Surface wave mitigation in a copper converter via H∞ mixed sensitivity control

Abstract

In this paper, a robust control strategy for surface wave mitigation in copper converters is presented. In copper converters, the purification of copper is carried out by injection of air into the molten bath through lateral tuyeres. The constant rate of air injection produces undesirable oscillation and splashing of the bath in the surface diminishing the lifetime of the internal cover. An H∞ mixed sensitivity approach is proposed to robustly control the air injection rate in order to eliminate the modes of oscillation in the surface even in the case when uncertainty in the parameters of the model and noise in the measurements are present. The effectiveness of the proposed approach is shown by simulations and by comparison with a non-robust LQG control strategy.