THEORETICAL ESTIMATION OF STABILITY IGNITION OF TYPICAL POLYMERIC MATERIAL BY LOCAL ENERGY SOURCE

Results of theoretical researches on estimation of stability ignition of typical polymeric material (PMMA) at interaction with the single steel particle heated to high temperatures in the form of a parallelepiped are presented in work. The mathematical model of process is presented by system of the nonlinear, non-stationary differential equations in private derivatives. It considers conductive heat transfer and thermal destruction in the condensed phase, diffusive and convective heat and mass transfer, besides oxidation of gaseous products of pyrolysis polymeric material in air. Depth of thermal decomposition of the near-surface layer, corresponding to depth of active PM pyrolysis zone (1#2) ·10–2 mm at its stationary burning, was chosen as the parameter characterizing steady ignition of PMMA. As a result of the analysis of integrated characteristics of process at variation of initial temperature of energy source three modes are allocated: gasification without ignition with the subsequent termination of pyrolysis (Tp < 700 K), steady ignition (700 K  Tp  1500 K), unstable ignition — flash (Tp > 1500 K).