Updated: Jan 29, 2021
Becht | Engineering Solutions, Plant Services, and Software Tool Provider
A client was operating an Exxon Model IV FCCU (fluid catalytic cracking unit). The main air blower steam turbine driver shaft experienced significant and continual axial movement in the direction of thrust that was approaching trip levels.
The client planned to temporarily replace the air flow from the main air blower to the regenerator using a number of rental compressors (47 proposed). Some compressors were diesel driven, and some were powered by 10 temporary generators.
A Becht team performed a cold eyes review of the installation of the temporary compressors, proposed control strategy, and startup/shutdown and transition procedures of the temporary system. The flow in the temporary air tie-in points to the main air line was high. A mechanical evaluation of these points was conducted to ensure there would be no failure in these areas due to high flow-induced vibration.