Simulation des interactions hydrodynamiques entre inclusions dans un métal liquide : établissement de noyaux d’agrégation dans les conditions représentatives du procédé de flottation

Abstract : Inclusion cleanliness remains a major challenge faced in process metallurgy in liquid phase. Flotation, the main process used in secondary metallurgy to remove inclusions, consists in injecting gas bubbles into the reactor. Rising gas bubbles entrap the biggest inclusions at their surface or in their wake. Besides, they promote collision and aggregation among particles. A 3D numerical model has been developed in order to quantify the roles of the prevailing phenomena on aggregation dynamics between inclusions in the vicinity of bubbles. At inclusion (mesoscopic) scale, the turbulent flow is locally modeled by a steady plane shear flow which is solved using a lattice-Boltzmann method. The coupling between both liquid and solid phases is ensured using an immersed boundary method. This method resolves the hydrodynamic perturbation induced by particles, and hence their interactions that are, in turn, used to update their Lagrangian tracking. The conducted numerical simulations bring out the influence of hydrodynamic effects on inclusion behavior. Collision cross sections have been determined from which ensuing aggregation kernels have been calculated. Such cross sections could provide macroscopic models to represent local particle dynamics. A first application of these results is presented to calculate aggregation frequencies in bubble swarms in a channel flow reactor that was simulated using DNS. Additionally, evolution of inclusion populations in molten steel has been determined from RANS simulation of a liquid steel ladle by means of a global population balance implementing the aggregation kernels determined in the present work.
Complete list of metadatas

Cited literature [108 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-02331097
Contributor : Thèses Ul <>
Submitted on : Thursday, October 24, 2019 - 11:48:13 AM
Last modification on : Friday, October 25, 2019 - 2:03:22 AM

File

DDOC_T_2019_0073_GISSELBRECHT....
Files produced by the author(s)

Identifiers

  • HAL Id : tel-02331097, version 1

Citation

Matthieu Gisselbrecht. Simulation des interactions hydrodynamiques entre inclusions dans un métal liquide : établissement de noyaux d’agrégation dans les conditions représentatives du procédé de flottation. Génie des procédés. Université de Lorraine, 2019. Français. ⟨NNT : 2019LORR0073⟩. ⟨tel-02331097⟩

Share

Metrics

Record views

74

Files downloads

17