Slab caster tundish configuration and operation - A review

Induced by the ever increasing cleanness requirements for flat products, slab easter tundish capacity has grown over the years. This was further supported by optimisation of steel flow through weirs/dams, often based on extensive flow modeling. Such efforts plus the maintaining of non-oxidising tundish slags and of inert linings seem to assure adequate cleanness control during steady state casting by preventing contamination of clean steel, and by ''refining'' of polluted steel through the flotation of large inclusions. It remains the main challenge for steel cleanness control i.e. mastering the transients at the start of casting and during ladle change. Here, large tundishes do not assure enough safety - regardless of configuration. Rather, the key features are ladle slag cutting, submerged ladle stream opening and with a ''broken'' impact velocity. Tundish inertisation and tundish heating are desirable, too; eventually also argon bubbling through the tundish bottom and/or MHD based features. In case of tundish hot cycling, first slab quality demands tundish slag conditioning. With such enhanced measures, tundish capacity may well be kept to more moderate dimensions (and lower height) - in favor of reduced operational cost and ease of handling.