METHOD OF REDUCTION OF NITROGEN OXIDES IN THE BOILER WORKING WITH DISPENCED CARBON WHERE INTERNAL COMBUSTION TYPE BURNERS ARE USED Russian patent published in 2012 - IPC F23C5/08 F23C99/00 

FIELD: energetics.

SUBSTANCE: method of nitrogen oxides reduction in the boiler working with dispensed coal where internal combustion burners are used. At this the method includes the following operations: all or part of burners for dispensed coal installed at the side wall (walls) of the boiler working in the regime of internal combustion, i.e. in the process of all work the ignition agents of the burners are maintained operating. In the conditions when dispensed carbon fuel ignites at injection from the burners the volume of secondary air fed into the primary combustion zone of the boiler is reduced. Due to this in the primary combustion zone there is a strongly oxidizing atmosphere, so the dispensed coal fuel is burnt in the conditions of high temperature and oxygen deficit. The residual air is fed into the furnace in the upper section of the boiler furnace as an overfire air creating the area of strongly reconstructing atmosphere, and as a result, the dispensed coal not totally burnt in the primary zone mixes intensively with air in this zone and fully reacts ensuring full combustion of dispensed coal. Internal part of each burner of internal combustion type is divided into several steps of combustion chambers. For the flow of primary air and dispensed coal in the burner they ensure division on the "compact/loose" type where the more compact dispensed coal flows to the central chamber and more loose dispensed coal goes to other combustion chambers. As a result the air and dispensed coal flow in the central chamber concentrates to the density level applicable for ignition. More dense coal in the central chamber of the burner ignites first with the help of ignition agent, and after that loose dispensed coal ignites due to the heat from the ignition and burning of the ignited coal. At this the dispensed coal burns in the burner in steps.

EFFECT: invention allows reducing NOx without reducing boiler effectiveness.

6 cl, 6 dwg