Speed Disturbance Compenation in the Secondary Cooling Zone in Continuous Casting.

Abstract

The continuous casting process is used for the solidification of molten steel into semi-finished shapes. Several factors influence the quality of cast steel, including mould level oscillation and cooling patterns in the secondary cooling zone. This article presents a dynamic model that can be used to study heat transfer in the continuous casting process. Temperature measurements in the secondary cooling zone are infeasible due to the effects of scale and steam on the measurement equipment. Two different feedforward controllers are proposed and compared to eliminate the effects of varying casting speed on the strand temperature; thus reducing the defects in the finished product. The first controller is based on typical controllers found in practice and a design methodology is proposed for the design of this controller. The second controller has dynamic properties and makes full use of the plant and disturbance transfer functions in its design. It is shown that disturbance rejection of the second controller is better than that of the first controller.