Combustion-Induced Rapid Phase Transition of CH4/O2/Inert Mixtures

Oxy-combustion is an important step towards zero-emission. However, over-adiabatic pressure shocks have been found when igniting oxygen-enriched lean or rich fuel mixtures in non-adiabatic reactors. This phenomenon has been demonstrated to be linked to the Rapid Phase Transition of water produced by the combustion reaction and, thus, it has been named "combustion-induced Rapid Phase Transition" (cRPT). In this work, we present further results of explosion tests in a non-adiabatic 5 dm(3) cylindrical vessel. In particular, we focused the attention on the role of nucleation sites on the occurrence of cRPT. To this aim, we sprinkled talc (fine powder) over the internal surface of the vessel, thus providing nucleation sites. Results show that cRPT may be prevented if nucleation sites are present at the vessel walls, thus favoring the evaporation kinetics and preventing the water super-heating.