The hydrodynamic performance of a gas-stirred ladle is analyzed experimentally, through a factorial experimental design, through physical modeling and particle image velocimetry techniques, to find the effects of the nozzle position, and its number, the gas flow rate and the presence or not of an oil layer on the flow velocity field, the turbulent kinetic energy distribution, and the open eye area, A. Flow patterns changed drastically in the presence of one or two plugs and as a result of the nozzle’s positions. The turbulent flow fields showed significant differences under the presence or absence of an oil layer and the open eye area strongly depends on the gas flow rate, the position and the number of nozzles. Responses , , and A were statistically processed to identify the relevant effects of each variable on , , and A. These responses were used to calculate the optimum process conditions that minimize A and maximize both and , and then improve mixing efficiency in ladles using multi-objective optimization through the genetic algorithm (GAmultiobj). A Pareto characterization and its analysis were performed to reveal the embedded operation rules allowing optimum performances of the ladle for specific production goals.

A mathematical model was developed to describe the hydrodynamics of a batch reactor for aluminum degassing utilizing the rotor-injector technique. The mathematical model uses the Eulerian algorithm to represent the two-phase system including the simulation of vortex formation at the free surface, and the use of the RNG k-ε model to account for the turbulence in the system. The model was employed to test the performances of three different impeller designs, two of which are available commercially, while the third one is a new design proposed in previous work. The model simulates the hydrodynamics and consequently helps to explain and connect the performances in terms of degassing kinetics and gas consumption found in physical modeling previously reported. Therefore, the model simulates a water physical model. The model reveals that the new impeller design distributes the bubbles more uniformly throughout the ladle, and exhibits a better-agitated bath, since the transfer of momentum to the fluids is better. Gas is evenly distributed with this design because both phases, gas and liquid, are dragged to the bottom of the ladle as a result of the higher pumping effect in comparison to the commercial designs.

Mixing phenomena in metallurgical steel ladles by bottom gas injection involves three phases namely, liquid molten steel, liquid slag and gaseous argon. In order to numerically solve this three-phase fluid flow system, a new approach is proposed which considers the physical nature of the gas being a dispersed phase in the liquid, while the two liquids namely, molten steel and slag are continuous phases initially separated by a sharp interface. The model was developed with the combination of two algorithms namely, IPSA (inter phase slip algorithm) where the gas bubbles are given a Eulerian approach since are considered as an interpenetrating phase in the two liquids and VOF (volume of fluid) in which the liquid is divided into two separate liquids but depending on the physical properties of each liquid they are assigned a mass fraction of each liquid. This implies that both the liquid phases (steel and slag) and the gas phase (argon) were solved for the mass balance. The Navier–Stokes conservation equations and the gas-phase turbulence in the liquid phases were solved in combination with the standard k-ε turbulence model. The mathematical model was successfully validated against flow patterns obtained experimentally using particle image velocimetry (PIV) and by the calculation of the area of the slag eye formed in a 1/17th water–oil physical model. The model was applied to an industrial ladle to describe in detail the turbulent flow structure of the multiphase system.

In this work, the Planar Laser-Induced Fluorescence (PLIF) technique is applied to study the effect of the number of nozzles, their radial position and the gas flow rate on the thermal mixing during the secondary steel refining under non-isothermal conditions in a water model. In the physical model, three burners have been used to simulate the arc heating during the liquid metal processing.The results suggest that an increase in the gas flow rate and injection nozzles located at the bottom of the model, in the same radial and angular positions as the heat sources affecting the liquid surface, improve the system’s heating efficiency.The use of PLIF proved to be a relevant tool to analyze the heat transfer phenomena and increase the thermal performance of the ladle, opening the possibility of carrying out experiments in non-isothermal physical models of steelmaking reactors, which are currently scarce.