Catalytic cracking unit lining issues

1 There may be overheating during operation; 2 the lining might not be of high quality; 3 there could be other stresses that have not been eliminated – it’s possible that unnecessary supports or restrictions were installed in the rising tube

1. Was the inner wall rust removed during lining installation? Was the material mixing ratio prepared as required? How much should be reserved for construction joints? Is the density of the anchor pins satisfactory? Was curing done after demolding? An insufficient grade of lining material can also cause the lining to bulge. 2. Excessive temperature during use of the equipment can lead to deformation of the equipment, as well as uneven expansion. As long as you identify areas with significant bulging, those areas must be removed and the lining redone; additional anchor bolts should be installed in areas where there is stress. If the work isn’t done properly before restarting operations and heating up the system, the lining will peel off and the equipment will get worn out, leading to serious accidents

1. The raw material riser located inside the regenerator and the lining of the stripping section are areas prone to failure. 2. The main reasons for this failure include: 2.1. Shape characteristics: The lining of the regenerator walls is concave in shape, while the riser and the stripping section are convex in shape. In the former, the lining expands when heated and is compressed by the constraint of the reactor wall, while in the latter, the lining undergoes tensile stress due to free thermal expansion. Without any constraints, even humans would act lawlessly, let alone objects: lol 2.2. Matching of expansion differences: Non-metals and metals have different coefficients of thermal expansion, and the temperatures of the lining and the metal pipe also differ; therefore, the lining and the metal will inevitably separate from each other. The lining in this area is fixed to the outer walls of the vertical pipes and the stripping section by means of anchoring structures; when these anchoring structures fail, the lining bulges or even comes off. 3. The linings on the vertical pipes and the stripping section are intended to reduce the excessive transfer of high temperatures from the regenerated catalyst to the unregenerated catalyst. If the catalyst circulation is not affected, it indicates that the slight increase in heat transfer is within acceptable limits. As for whether to replace the bulged lining, the user needs to assess whether there is a possibility of large-scale peeling during future operation cycles.