Strength And Safe Reliability Analysis Of Refractory Lining Internal Plenum In Large-Scale FCC Units

Refractory lining equipments are the key and important equipments in the FCC&MTO units. The inside wall of the metal shells and the surface of the internal parts are generally installed heat insulation or anti-abrasion refractory. Damage and failure of the refractory are the main reason of the unit shut down. Not only in domestic but also abroad, stress calculation and analysis are usually thought about in the metal design and ignored in the refractory design.The method of thermal calculation, damage analysis and failure evalution of refractory are given. Some key issues are analysised for refractory-metal coupling model. Several types of strain-stress formula are put forward. The refractory metal coupling models with and without anchors are built. The temperature and stress distribution are calculated. By using the “Reverse approach” method, the heat-transfer coefficient and other parameters of the model without anchors are revised. A set of small-scale heat test unit are built and the research result show that the numerical simulation are accurateThe strength evaluation and failure criteria of the refractory material are given. The elastic model and the advanced bilinear kinematic hardening model BKIN are used to simulate the condition of heat-insulating refractory under the action of the thermal and mechanical stresses. The damage positions and destruction form are found at the case of difference design conditions.Full-size model of the refractory lining internal plenum is built to analysis deformation, temperature distribution and stress distribution for both refractory material and metal material. Considering the load status of the plenum, damage conditions and failure modes are analyzed to make stress assessment of hazardous locations. The effect law for the metal caused by different degree of the demage and failure of refractory are declared.Optimization of 6 design variables of the plenum is made at the base of the metal deformation and stress. New design is made according to the optimization results. Sensitivity analysis is made using both directly method and Latin hypercube sampling method to find out the effect law for reliability caused by main design factors. Thermal and mechanical fatigue life analysis is performed according to the ASME-Ⅷ-2 fatigue design method. The fatigue life are known and the factors that affect the life of the device are gotten. At the lifting plate welding position, after the partly damage of the refractory, the fatigue life will be changed. The article provides a set of strength evaluation and fatigue analysis methods and criterias for refractory equipments. It provides benefitable guide and references to improve the refractory design and raise the reliability of refractory lining equipments.