Numerical simulation for the thermal regime of slag-splashing lance during hot repair of BOF lining

Abstract

Computer modelling is increasingly essential for advancing the practice of the most widespread and efficient basic oxygen furnace (BOF) steelmaking process. An urgent problem in the BOF process is the need for greater durability of the refractory lining in the top-blown converter. One of the most advanced methods of hot repair for the converter lining is the inter-melting slagging technology for refractories, with a durable skull coating. An essential task in implementing the progressive slag-splashing process is ensuring proper and stable durability of the slag-splashing lances used. A mathematical model of the thermal regime of the top water-cooled slag-splashing lance barrel during the hot repair operation of the converter lining by the slag-splashing method has been developed. The regularities of heat transfer and temperature changes in the outer pipe of the slag-splashing lance for two primary forms of blast devices, operated under technological conditions of lining slagging in top-blown converters with typical capacities of 160 tonnes and 250 tonnes, are numerically investigated. Regression dependencies for estimating the thermal regime of the slag-splashing lance barrel at different cooling water flow rates have been obtained. The results obtained are used to design a slag-splashing lance and to develop its operating technology during hot repair of the lining of a 250-tonne top-blown converter with the use of the slagging method. The results contribute to the development and improvement of automated design systems, the modernisation of slag-splashing lances, and the control of BOF steelmaking. They also contribute to the development and improvement of automated design and modernisation systems, as well as to the solution of optimisation and predictive analysis problems for the thermal regime of slag-splashing lances in the context of BOF steelmaking control.