Thermal Stress Analysis Considering the Effects of Pyrolytic Gas Flow in Lump Coke

The thermal stress analysis of a packed bed of coal is performed to estimate the heat and mass transfer rate in the coke oven chamber. The flow model of pyrolytic gas released from coal is included in the conventional thermal stress analysis model and the effects of gas flow on temperature and stress field within the lump coke are investigated. The flow field within the packed bed of glass beads, modeled on coke having a plastic layer and macro-crack, is observed using the visualization technique. As a result, the gas flow model is able to represent the pyrolytic gas flow within the lump coke. As the pyrolytic gas mainly flows out from the macro-crack surface rather than the heated wall side surface, the temperature difference between the crack surface and the inside of the coke becomes smaller than the conventional result. This model cannot predict the formation of micro-crack arising from the macro-crack surface since only the compressive stress is still predicted at the macro-crack surface. The model, however, suggests that simultaneous achievement of coke quality enhancement and energy-saving may be prossible by effective gas extraction in the coke-making process.