Abstract: The damage of center pipe in CCR reactor is one of the main reasons for unscheduled shutdown in CCR unit. This paper analyzes the design, fabrication and operation of center pipe based on the feedback from jobsite. It comes to the conclusion that the main reason for the damage is the deviation of the actual situation from the design assumption and exceeding the design safety range, thus resulting in the instability of the center pipe. Then the paper puts forward corresponding design revision and structure improvement measures, which extends the service life of the center tube effectively. Meanwhile, it also proposes the key parts of the center pipe to be inspected during the shutdown and maintenance period and the determination method for safety so as to ensure the safe, stable and long-cycle operation of the reactor.

Key words: reforming reactor, center tube, damage reason, structure improvement