Effect of Surface Dry Layer Thickness on the Smoldering Combustion of a Stratified Moisture Content Peat Layer
Various laboratory-scale researches are still developed to study the phenomena of peat fires. In general, research on the dynamics of peat smoldering combustion is carried out on samples with uniform moisture content (MC), both in dry conditions as well as with certain levels of moisture content. This research conducted to study the ability of moist peat burned under variations of the thickness of the dry peat layer on the top layer and the lower layers with stratified MC that increases with its depth. Measurements of temperature, mass, and MC change are in real-time during the test. The test results showed that by a thin dry surface layer of samples, the smoldering combustion couldn’t sustain for long. Combustion on the thick dry surface layer will generate sufficient heat energy to maintain the evaporation and drying process which will continue to the stage of fuel oxidation and char oxidation to the deeper layers. The thicker the smoldering layer, the greater the heat released, the faster the evaporation process, the faster the smoldering propagation rate, and the burning can reach the innermost layer even the natural wet peat layer.
Keywords: Stratified moisture content, temperature, mass loss rate, evaporation, heat balance, depth of burn