Investigations on the self-ignition of deposits containing combustibles

摘要

Self-ignition of deposited combustibles is a possible reason for excessive fires occurring on deposits for recycling materials or on waste dumps. Two series of experiments were performed to assess the hazard of self-ignition: hot storage tests with different homogeneous mixtures of combustible material and inert material and tests with pockets of combustible material embedded in inert matter. In the first test series considerable exothermicity (△T＞60K) was observed for mass fractions of combustible material as low as 2.5%. In the second series it could be shown that the heat transfer from a pocket of burning material through the inert matter can ignite a second pocket of combustible matter. Based on the experimental data, numerical simulations were performed to predict self-ignition on real-scale waste deposits. For a deposit of specific size and shape, the influence of the ambient temperature on the occurrence of self-ignition has been investigated.