Performance of a Nozzle to Control Bath Level Oscillations and Turbulence of the Metal-Flux Interface in Slab Molds

Rodolfo Davila Morales,Carlos Rodrigo Muñiz-Valdés,Javier Guarneros,Alfonso Nájera Bastida,María Guadalupe González-Solórzano

doi:10.3390/met12010140

Rodolfo Davila Morales, Carlos Rodrigo Muñiz-Valdés + Show 3 more

Open Access

https://doi.org/10.3390/met12010140

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Abstract

The characterization of the turbulent flow of liquid steel in a slab mold using a commercial nozzle was carried out through physical experiments and mathematical models. Six ultrasonic sensors were located at each side of the nozzle to obtain real-time plotting of the bath levels during the experimental time. An ultrasonic transducer located in the mold, 20 mm below the meniscus, determines the velocities and the turbulent variables along with the distance from the narrow face to the position of the nozzle’s outer wall. These data, together with the mathematical simulations, demonstrated a high correlation of bath level oscillations and the time-dependent behavior of the discharging jets. The flow inside the mold shows low-frequency non-symmetric patterns without a severe turbulent in the meniscus. The source of this instability is the partial opening of the slide valve gate used to control the mass flow of liquid.

Highlights

The fluid flow of liquid steel in continuous casting molds is critical to cast highquality slabs
The literature in the field dealt with the effects of nozzle immersion depth, casting speed, steel grade, and thermo-solute convection on the fluid patterns of liquid steel in slab molds [7,8,9,10,11,12]
To capture the general feature of the flow, a red dye tracer, consisting of an aqueous solution of a food colorant, is injected by a syringe through a drill performed in the upper tube nozzle (UTN), sealed with a rubber plug

Summary

Introduction

The fluid flow of liquid steel in continuous casting molds is critical to cast highquality slabs. The metal-slag interface is under the effects of shear stresses originated by the upper roll flow causing waves, leading to instabilities of at the melt surface, for any given casting speed, avoids flux entrapment and the derived generation of slivers [16,17]. To capture the general feature of the flow, a red dye tracer, consisting of an aqueous solution of a food colorant, is injected by a syringe through a drill performed in the UTN, sealed with a rubber plug Another drill practiced in the midface of one of the narrow faces, located 20 mm below the water meniscus, holds an ultrasonic transducer of 10 million Hertz that receives the signals of the liquid’s motion. It is evident that a water model does not reproduce faithfully the current flows in slab molds, the overall flow patterns in casting systems will follow those reported here

The Mathematical Model

Si j ε

Results and Discussion

Conclusions