Multistage flameless oxidation

Flameless Oxidation (FLOX®) is a well established low thermal NOx combustion method since the early 1990s. Flameless Oxidation can be applied for processes above self ignition temperature. Typically, switching between flame- and FLOX-mode occurs at a temperature of 850°C. This restriction can be omitted when applying multistage flameless oxidation where a burner can be started directly from cold or after a short preheat. The air/fuel ratio in a first stage flameless oxidation under adiabatic or near adiabatic conditions is chosen to guarantee stable combustion but suppress NOx-formation. This is followed by a complete oxidation of the hot fuel/exhaust or oxygen/exhaust mixture in a heating chamber. The method is characterized by a high degree of fuel flexibility and has the potential to suppress both, thermal and fuel NOx.