Simulation of the co-combustion of loaden activated char coal in a waste incineration plant

Activated char coal filters are widely used as the final stage of flue gas purification behind waste incineration plants. The used activated char coal, loaden with sulphurdioxide, metals, mercury, dioxines, furanes and other pollutants, shall be burned in the combustion chamber of the plant. In order to achieve a stable ignition and complete burnout of the char coal, an newly developed Oxygen-Pulverized fuel burner is used. The pulverized char coal is pneumatically transported using due to safety reasons technical pure Nitrogen as transport gas into the burner. Technical pure Oxygen is added as oxidizer through coaxial channels and swirler blades. To predict both the efficiency of the burner and the influence on the flow field, emission and fouling behaviour of the combustor simulations were carried out using the threedimensional CFD-code FLOREAN. Despite the small thermal capacity of the burner compared to the thermal capacity of the burned waste locally significant changes occur in the flow- and temperature distribution inside the combustion chamber. Beside a slightly raise of NOx-emissions high local temperature peaks can lead to additional fouling and slagging of the furnace walls.