Stabilization of the molten steel level in the mold of a continuous casting machine by means of vacuum

A MIMO model-based controller to stabilize the molten steel level in the mold and the tundish in a one-strand continuous casting machine is developed; to stabilize the mold level the pressure in the vacuum chamber of the tundish is employed as control input, while to stabilize the tundish level the position of the slide-gate valve of the ladle is utilized as control input. Given the nonlinear relationship between the pressure and the outlet flow from the tundish nozzle, a simple linear link between the aforementioned variables is assumed in order that the feedback linearizing technique can be applied. Numerical simulations show the good dynamic performance of the controller proposed, corroborating the viability of the vacuum technique to regulate the level of molten steel in the mold