Fatigue Lifetime Assessment for Adsorber Pressure Vessel Through Simulations and Experimental Validation

The adsorber pressure vessels in an onshore gas processing unit experience cyclic thermo-mechanical loading due to fluctuating gas temperatures, ranging from 20° C during the drying phase to 250° C during regeneration. Each regeneration cycle lasts between 1-2 hours, while the duration of the drying stage depends on the gas flow rate. These vertically operated vessels consist of a cylindrical steel shell with a semi-spherical head, internally lined with refractory material to minimize thermal stresses and protect the vessel wall. A finite element model (FEM) is employed to analyze thermal stresses, employing on an axisymmetric representation of the cylinder, top head, and nozzle. Data from cyclic operational stresses are analysed to estimate fatigue crack initiation by pressure vessel design codes. Thermographic imaging, which captures external temperatures, is compared with simulation results. The study leverages surface temperature data to assess cyclic stresses in the shell and predict the vessel's fatigue life.