Marcus Malow

Smoldering combustion of solid bulk materials at different volume fractions of oxygen in the surrounding gas

Fires in storage facilities of bulk goods, recycling materials, granules or dusts are mostly smouldering or glowing fires producing large amounts of gases which are released to the environment. Many of these fires are due to preceding self-ignition of the material. The current paper presents investigations on lab-scale on the influence of the volume fraction of oxygen in the gas surrounding the bulk material on the reaction temperatures, the mass loss and the composition of the flue gas during smouldering fires triggered by selfignition. This reflects the conditions present e.g. in silo fires, where the access of oxygen to the reaction zone is hampered. The composition of gaseous reaction products was measured using FTIR spectroscopy, the mass loss of the solid fraction during the combustion was observed using a thermogravimetric scale. It was found that the volume fraction of oxygen significantly changes reaction temperatures, the rate of mass loss and the composition of the flue gas.