PSI - Issue 3

J.L. González et al. / Procedia Structural Integrity 3 (2017) 48–56 Author name / Structural Integrity Procedia 00 (2017) 000–000

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Fig. 2. Bulging deformation of a shell section of the reactor as consequence of the overheating.

Fig. 3. Microstructure of the reactor damaged zone.

These findings demonstrated without doubt that the damaged section went on the creep regime and the defects developed as a consequence of this mechanism were: shell distortion, metal softening and metallurgical alteration. It was found also that the overheating was caused by the collapse of the internal refractory lining. An initial qualitative integrity assessment of these defects clearly indicated that the damaged section was in a reject condition. Since it was not possible to shut down the FCC plant immediately after the overheating was detected, the plant operator asked the question of how much time the overheated shell section could operate without collapsing? And after that, what actions could be taken to rehabilitate the damaged zone and put back in service the reactor as soon as possible? This paper describes the assessments made based on the classical methodologies of fitness for service to answer the first question and the design of reinforcement that fulfill the requirements of the applicable codes and standards and allow the reactor to go back in service in a safe and reliable way.