Mathematical maximisation of minimum residence time for two strand continuous caster

The present paper contains the results of a design optimisation study of a new enlarged tundish at ISCOR, Vanderbijlpark Works, Vanderbijlpark, South Africa. The paper describes the use of computational fluid dynamics (CFD) combined with mathematical optimisation to design the configuration of the new enlarged tundish. Design variables chosen include the position and sizes of baffles and baffle holes and pouring box width, while the design objective is maximisation of the minimum residence time (MRT) at operating level and at a typical transition level. Two different optimisation methods (DYNAMIC-Q and LS-OPT) are used and compared in the study. The combined MRT obtained by DYNAMIC-Q is 0·4, while LS-OPT converges to a value of 0·43, both starting from a combined MRT of 0·21. The study shows how mathematical optimisation techniques can be coupled to a commercial CFD package (FLUENT) to obtain optimum tundish designs with significant improvements. The CFD process is validated using plant data for similar designs.