CFD Modelling of Inconsistent Furnace Taps

Abstract

During tapping of ferroalloys, significant variations between consecutive taps are observed. This inconsistency is not properly understood. It has been hypothesized that the inconsistencies are caused by changes in furnace conditions between taps. The configuration of particles in the burden consisting of coke and minerals can change due to forces exerted during closing and opening of tap-holes or due to other movements in the particle bed. Earlier studies with CFD have not revealed any inconsistent tapping since they have assumed non-varying and often ideal uniform particle bed configurations. Here a sensitivity study is presented where particle conditions are non-uniform and these represent configurations which could represent real consecutive variations. The results show that large variations between taps will happen if there is a small variation in particle bed configuration close to the tap-hole entrance. In this region variations are likely due to the forces exerted during opening and closing of tap-holes.