Nature protection technologies

1.1.2.2.5. Three-staged combustion

Part 1. AIR PROTECTION FROM POWER INDUSTRY EMISSIONS

1.1. Nitrogen oxide emission reduction

1.1.2. Technological methods of nitrogen oxides reduction in boilers at combustion of different types of organic fuel

1.1.2.2. Modernization of the furnace process

1.1.2.2.5. Three-staged combustion

Kotler V.R., Open JSC “VTI”

One of the most effective methods, providing a partial reduction of the already formed NOx to N2, is a three-staged combustion method, called in the U.S. and Western Europe as a reburning process. An essence of the method is that into the primary burners (working with the optimum excess air in terms of efficiency) only 75 ... 85% of all fuel is supplied. The remaining 15 ... 25% is fed into the intermediate zone of the flame (above the primary burners) with a great lack of air. This results in formation of the reducing zone, in which due to hydrocarbons and nitrogen-containing components (eg, amines) NOx is reduced.