Effect of Thermal Radiation on Initiation of Flame Instability in Moisty Organic Dust Combustion

In this paper a model is presented in which thermal radiation is taken to account in order to predict initiation of flame instability. One dimensional model is used to evaluate the flame characteristics. In order to analyze the flame structure, it is divided into three zones: preheat zone, reaction zone and post-flame zone. Preheat zone is also divided into four subzones: first heating subzone and drying subzone, second heating subzone and volatile evaporation subzone. Then governing equations are written and they are made dimensionless by using space-time (z ,h,t ) coordinates. Then these equations are solved. By considering thermal radiation amount of induced heat from reaction zone into the preheat zone increases. This plays a significant role in the improvement of vaporization process and burning velocity of organic dust mixture, compared with the case in which the thermal radiation factor is neglected. According to results, burning velocity and initiation of flame instability strongly depend on radiative heat transfer. By considering thermal radiation effect, obtained burning velocity has better agreement with experimental data,and consequently our model is more reliable to use.