Fluid Flow through Continuous Casting Nozzles

Don Hershey, Fady Najjar and Brian Thomas

Continuous Casting Consortium

Turbulent fluid flow of molten steel through bifurcated nozzles into the continuous slab casting mold is being modeled using steady two and three dimensional finite element models. Effects of process variables and nozzle geometry on the flow pattern, velocity exiting the nozzle, and asymmetry are being investigated and compared to results from water models. The results are needed to determine inlet conditions to the mold, in addition to understanding flow-related defects.

This figure shows the typical velocity pattern calculated in one quarter of a continuous casting Submerged Entry Nozzle (SEN). Steel flow exits the nozzle at a steeper downward angle than machined into the ports. Swirl is also imposed onto the steel, as the jet spirals outward into the mold cavity. A recirculation zone is seen at the top of the nozzle, where steel actually flows back into the nozzle. This is due to the oversize nature of the nozzle ports. This region is thus prone to clogging buildup and makes the top surface of the outlet port ineffective at directing the flow.