Evaluating the Thermal-Mechanical Response and Fatigue Life of Different Coke Drum Support Skirt Designs

It is well known that coke drums are subjected to severe operating conditions that can lead to progressive plastic strain accumulation and related fatigue damage and cracking. The difficulties of performing an insightful, useful coke drum analysis are numerous. There are a variety of uncertainties and randomness in temperature and stress during the heating and quench portions of the operating cycle that limit the value of conventional analysis for remaining life prediction. Further complicating the issue, the progression of damage in coke drums often involves gross plasticity, permanent dilation, and variable bulging in the pressure boundary. Since the accumulation of damage in the drum is a history (or path) -dependent process, a snapshot of strain or even distortion data has limited value in quantifying damage or remaining life.