An area surrounded by a burning front or burning particle is called a flame. Some refer to the regular flame formed by jet as the torch.
Flame can be classified according to different side characteristics. For example, according to the fuel type, it can be divided into gas flame, oil fog flame and pulverized coal flame, divided into homogeneous flame and heterogeneous flame according to the phase composition of the flame, DC conical flame, swirl flame and flat flame according to the flame geometry switch. According to the premixing degree of fuel and air: premixed flame (dynamic combustion flame), diffusion flame and intermediate combustion flame; according to the flow properties: laminar flame, turbulent flame. For gas, the characteristics of combustion process are premixed flame, diffusion flame and swirl flame.
