Method for conducting combustion in a furnace in order to limit the production of nitrogen oxides, and installation for implementing said method

Abstract

A method for conducting combustion in a fluidised bed furnace, in particular having a sand bed, according to which a flow of primary combustion air is blown through the bed, the fuel consisting in particular of organic waste, or of municipal waste, or of sludge from purifying stations, it being possible to inject secondary air (5a) into the space (5) in the furnace located above the bed; in order to limit the production of nitrogen oxides NOx and nitrous oxide N2O: the nitrous oxide N2O and nitrogen oxide NOx content of the fumes at the outlet of the furnace are measured (12, 20); the temperature of the fluidised bed is controlled to keep it at the highest admissible value at which the production of nitrous oxide N2O is substantially reduced, while the production of nitrogen oxides NOx is not substantially increased; and the excess air in the fluidised bed is controlled to keep it at the lowest admissible value at which the production of nitrogen oxides NOx is reduced without adversely affecting the combustion and the temperature of the bed.

Dependencies are inferred from the claim text.