Modeling the effects of a swirling flow on temperature stratification of liquid steel and flotation of inclusions in a tundish

摘要

A conventional ladle shroud (LS) is compared with a swirling ladle shroud (SLS) from the points of view of fluid flow dynamics and removal ratio of inclusions from liquid steel flowing through a tundish using water modeling and fluid dynamics approaches. In this tundish the LS generates vortexing flows at the tundish outlets that disappear with the existence of high temperature gradients inside the liquid phase. On the other hand, the SLS avoids efficiently the formation of vortexes and recirculating flows either under isothermal and non-isothermal conditions. Buoyancy forces generated by changes of liquid density enhance upward velocities enhancing the flotation rate of inclusions. The conventional shroud does not promote this effect due to the existence of the vortexing flows. Eventually the LS would drive the fluid toward the bath surface forming entrainment of slag particles by liquid steel while the SLS yields a low turbulent entry jet. The SLS is a good alternative to substitute the current flow control devices available in the market.