A Laboratory Scale Plug Flow Reactor for Mild Combustion

High levels of reactant preheating and dilution, characteristic of Mild Combustion, provide for a high efficiency in oxidation of conventional and non-conventional fuels as well as in pollutants abatement. The peculiarity of Mild Combustion makes difficult a rational design of reactors which operate under such conditions. This does not depend on the reactor size hence it is reasonable to face these difficulties by means of simple-small reactor. In the full paper the configuration and the design of a laboratory scale reactor for Mild Combustion of gaseous fuels, diluted with super heated steam, will be presented and discussed on the basis of the main constrains of the problem, namely the very high inlet temperatures (from 1000 up to 1800K) and the need for spatial and/or temporal resolution. A plug flow reactor configuration has been chosen to this purpose. Mass flow rate, diameter and residence time have been evaluated in order to have a turbulent field and a high axial resolution of the oxidation process. Particular attention has been devoted to the fuel injection section because fuel/oxidant mixing has to be very efficient due to the very short reaction times in combustion system. Gaseous jets in cross flow configuration has been chosen. Number, shape and diameter of injection holes have been carefully assessed and designed taking into account the very high inlet temperatures. The potentials of the reactor for studies related to pollutant abatement in energy production systems are discussed.