Simulação CFD de calcinadores da indústria de cimento visando redução de NOx via queima estagiada

Abstract

Nitrogen oxides (NOx) emissions are being more and more controlled by specific environmental laws, due to its hazards effects as acid rain and photochemical smog. This work evaluates the NOx formation and reduction in clinquerization systems, specifically in calciners. Two calciner designs were studied via Computation Fluid Dynamics (CFD), one in-line with the kiln and other in-line with the kiln with a combustion chamber. Despite the differences in their designs, the NOx emissions at the calciners outlets were similar. The staged combustion and reburning are among the most effective and low cost techniques implemented to reduce NOx emissions. Additional simulations were run in order to evaluate the implementation and optimization of these techniques. It was possible to achieve 33% reduction on NOx emissions.