Numerical modelling for characterization of the granular flows impact on the gas flow in a packed-bed-reactor

Abstract: The goal of the project was to characterize the granular flows impact on the gas flow in a packed-bed-reactor. The study was created at Swerim as a master's thesis for Luleå University of Technology. The packed-bed-reactor geometry used in this study is a scaled down blast furnace model. The granular flow was modelled using the discrete element method (DEM) in LS-DYNA. Four models were created with different sizes and size distribution of the particles. To study the granular flows impact on gas flow, porosity is extracted from the DEM models and analyzed, since porosity has a direct impact on the gas flow. The supervisors form Swerim, Joakim Eck and Martin Flemström created computational fluid dynamics (CFD) models in Ansys Fluent using the porosity from the DEM models. The DEM results are presented as granular flow profiles. This flow profile is created by injecting particles with alternating colors to see this profile. A total of 6 images are taken over the whole process. The porosity results are presented as a porosity field plots of the extracted porosity data using MATLAB. The CFD results are presented as plots of gas velocity and absolute pressure. The results show the different characteristics of the flow in the different DEM models, and how it relates to the different porosity fields that were found. Furthermore, the CFD models show how the flow of the gas is dependent on the porosity.