Hydrodynamic analysis of gas‐liquid‐liquid‐solid reactors using the XDEM numerical approach

Abstract

Multiphase reactors are abundantly used in many industries. Among them, few reactors deal with four phases called gas-liquid-liquid-solid systems, which receive less attention due to their complex situation. Numerical study of such complex systems is not easy and requires large computational effort. In this study, a discrete-continuous numerical model known as the eXtended discrete element method (XDEM) is proposed to investigate the hydrodynamic behaviour of fluid phases passing through the packed bed of solid particles. This model is applied to the dripping zone of a blast furnace. In this zone, two distinct liquid phases, namely liquid iron and slag, flow through a pile of coke particles while exchanging momentum. In this work, besides the solid-fluid and gas-liquid interactions, the liquid-liquid interactions are also studied and the phases' mutual effects are discussed. In addition, a sensitivity study on the slag viscosity is performed, which shows the importance of liquid phase properties on the system behaviour. The results evaluation shows that the liquid iron accelerates the downward flow of the slag and the slag decelerates the downward flow of the liquid iron phase due to the resistance force caused by their relative velocity.

XDEM study of burden distribution in iron ore pellet firing

“…Thus, this study utilizes the Eulerian–Lagrangian approach for the modelling, in which gas and solid are treated as a continuum and discrete phases accordingly. Particle-related processes are addressed with an extended version of DEM which is also referred as eXtended Discrete Element Method (XDEM) [24,25]. The current study aims to evaluate the effect of possible burden distribution strategies for alleviating the final product inhomogeneity and improving the thermal state during the heat hardening oxidation of iron ore pellets.…”

A numerical study on the softening process of iron ore particles in the cohesive zone of an experimental blast furnace using a coupled CFD-DEM method

“…The XDEM has been applied to different phenomena taking place in the blast furnace. In particular, it has been validated for the heat up and reduction of iron ore pellets in the shaft [18,19], and the flow behavior of molten iron and slag through a packed bed of coke particles in the dripping zone [20,21,22]. To fulfill our ultimate goal, which is the modeling of a blast furnace using the XDEM, the phenomena inside the CZ also need to be modeled.…”

Issue Highlights

“…In order to unveil the underlying physics, the innovative approach of the extended discrete element method (XDEM) was developed. The solid phase consisting of particles is treated in a Lagrangian framework while the flow consisting of a gas and liquid iron and slag within the void space between the particles is described by advanced computational fluid dynamics (CFD) that estimates the temperature, velocity, and composition of each phase …”