SINOPEC Jinling Company modified its start-up procedures of flue gas expander train of the No.1 FCCU to minimize the surge to the local power grid at the start-up of flue gas expander train.The expander is first impulse rotated to the 80%of the rated speed of the train before start-up of motor so as to reduce the start-up current of the motor,shorten the start-up time and ensure the safe operation of other equipment in the power grid.The procedures for impulse start-up of expander-air blower-motor train are analyzed and critical operation procedures are highlighted.Improvements are recommended to minimize the impact of start-up speed on critical parameters.

The axial-flow air blower of the 1.3 MM TPY FCCU in SINOPEC Jinling Company was shutdown by interlock system after high vibration alarm in July,2009.the inspection of axial-flow air blower found the root fractures of 3 rotor blades,development of deformation of part of rotor blades and a number of fracture gaps in the blades.The comprehensive analysis in respect of blade fracture,operation conditions,operating vibration and flow variations has concluded that the blade fractures is the result of typical fatigue fracture and fabrication defect is the fatigue source of blade roots.Measures for maintaining long-term operation of axialflow air blower are presented.