Combustion system for industrial boiler

摘要

The apparatus is used for reduction of nitrogen oxides in the flue gases from an industrial boiler. There are four rows of burners (18-21) in the sidewall (7) of the combustion chamber. The lowest two rows have four burners each. The burners in each row are vertically aligned to form vertical rows. The top burners may discharge powdered coal at an angle. The top two rows of burners have two extra burners, making rows of six burners in all. There are three grinding mills supplying the burners with powdered coal. There are nozzles for additional air (22) above the top row of burners. An under-stoichiometric mixture burns in the first two combustion zones (25a,b) and above that there is a NOx reduction zone in which the reaction:- 2NO + 2CnHm + (2n + n/2-1)O2 changes to N2 + 2nCO2 + H2O can take place.