FLAME STRUCTURE IN HOMOGENEOUS AND HETEROGENEOUS MIXTURES NEAR THE LEAN FLAMMABILITY LIMIT

In this work the structure and the mechanism of the flame propagation in gas dust and dust-gas mixtures near the flammability limit was studied. Experiments were conducted mainly in a rectangular duot of dimensions 0,035 x 0,088 m2 and in length 1,2 m. Interferometrio cinematography as well as direct frame, streak and compensation photography were used for this study. Temperature measurements with a resistance thermometer were also conducted. Lignite dust were used in tests and in hybrid mixtures technical me theme was used as the gaseous fuel. It was found that dust and dust-gas flames under the same testing conditions have a very different structure than gas flames. The simplified model of flame propagation in dust-air mixtures at conditions close to the lean limit is presented on the basis of the conducted experiments.