A Computational Fluid Dynamics (CFD) work was performed in order to study the flow field produced by a swirlstabilized axi-symmetric laboratory burner with adjustable aerodynamics that has been designed and constructed as a scale model of an industrial coal burner, in three successive steps. In this paper results from the third step are presented and discussed where the burner operates under combusting conditions and is fixed to a cylindrical furnace equipped with a ceramic lining. Results reveal that the flow patterns are significantly affected by the surrounding wall, which imposes a secondary corner toroidal vortex, as well as the enhancement of the central recirculation zone which dominates the flow field inside the furnace, for both swirl levels examined.