The Mild Combustion is a relatively novel combustion technique characterize
d by both an elevated temperature of reactants and an adiabatic flame tempe
rature not higher than 1600K. These features are the results of several tec
hnological demands coming form different application fields.
The main advantages derived by Mild Combustion concern both the combustion
process itself and its applications. In the former case the pollution reduc
tion, the increase of efficiency process and fuel flexibility has to be con
sidered whereas the latter one is principally related to heat treatment pro
cess and wall confinement.
In this paper, characteristics of Mild Combustion are discussed with partic
ular regards towards the aspects of plant design. A general classification
of the processes, where initial and adiabatic temperature values are differ
ent from characteristic ones of classical combustion system, is given. This
classification leads to a definition of Mild Combustion process as a direc
t consequence of technological evolution and practical constrains, especial
ly related to environmental problems. In this sense, the high temperature o
f reactants and the low adiabatic temperature, principally obtained using e
xhausts for both heat recovery and dilution, can not be considered independ
ently. Application of Mild Combustion in practical systems infers the use o
f particular solutions because of high temperature of reactants involved. I
n the final part of the paper, specific solutions utilized in a laboratory
mild combustor are presented.