Model based scheduling of a continuous annealing furnace

Abstract

The operational complexities and process constraints of an industrial continuous annealing operation invariably lead to empirically designed process cycles as well as manual scheduling practices. This methodology often results in suboptimal and inefficient operations. An integrated approach is presented here for maximising the productivity of a continuous furnace, where bundles of steel rods are annealed. For this purpose, a scheduling algorithm is proposed, which is coupled with a process model. The phenomenological process model is based on heat transfer and annealing kinetics. The scheduling algorithm is formulated to analyse the continuous annealing furnace under different operating conditions. The advantage of coupling the scheduling algorithm to the process model in enhancing productivity has been illustrated. Furthermore, it is shown that optimising the bundle diameter at a constant hearth speed is favourable for frequent dispatches of the product, whereas for less frequent dispatches, it is more efficient to vary the hearth speed.