CFD simulation of reactive flow in parallel flow regenerative shaft kilns using porous media model

Abstract

Understanding the flow pattern of the gas jets in packed beds can have considerable significance in improving reactor design and process optimization. This study researches the fuel diffusion in the radial direction and the flame length in a packed bed of a Parallel Flow Regenerative (PFR) Shaft kiln. This kiln is characterized that the fuel is injected vertically in the packed bed using a lot of lances in the cross-section while the combustion air is distributed continuously. Such a large, packed bed has to be approximated as a porous media. This assumption is used to model the reactive flow in the kilns. Using a box with 700 spheres of 52 mm spheres in Body-Centered Cube (B.C.C.) arrangement the local concentrations of injected nitrogen in airflow were measured. The measured values match approximately with those calculated with the Porous Media Model (PMM). The studied parameters are the number of burners and burner arrangements. The radial mixing of fuel and air in a packed bed is relatively bad. Therefore, a lot of burners are needed for better temperature homogenization in the cross-section.