METHOD AND APPARATUS FOR REDUCING THE GENERATION OF NOX DURING COMBUSTION OF COAL DUST

摘要

When coal dust is combusted in burners together with combustion air, especially when the coal dust is fed by way of a primary air as stream and in the form of a coal dust/primary air mixture, a primary gas with combustible, gaseous components is generated from the coal dust/primary air mixture in the ignition zone of the burner by pyrolysis of the coal dust. In order to achieve a reduction in the NOx generated during combustion of the coal dust, the average ratio in the ignition region of the amount of oxygen in the primary gas to the amount of oxygen required for complete combustion of the volatile combustible components in the primary gas is lowered. This is achieved by either reducing the relative amount of oxygen in the primary gas and/or injecting a combustible external gas into the primary gas in the ignition zone.