The operation of electrostatic precipitator(EP) originally equiped for circulating fluidized bed(CFB) boiler in one power plant has deteriorated due to change of the operating condition. the dust removal efficiency can’t reach the requirement of pollutant emission standard for environmental protection. For this

it is retrofitted into a dust collector combining EP with bag filter. Combined with practical engineering project

the structure and arrangement mode of ash-cleaning nozzles for the bag filter have been studied

at the same time

the gas flow distribution between EP and bag filter being optimized. After retrofitting

the concentration of smoke emission has been lowered from 600 mg/m3 to below 28 mg/m3

the operation of retrofitted equipment being stable and reliable

attaining the anticipated target.