By applying low-pressure impactor system

particulate matter(PM)measurements were performed at the inlet and outlet of the fabric filter(FF)and the outlet of limestone-gypsum wet flue gas desulfurization(WFGD)tower in a 220 MW pulverized coal fired power plant unit.The PM formation characteristics

the FF's dust removal characteristics and the influence of the WFGD system on PM emission were discussed.The results show that

the PMs were of bimodal size distribution and the PM0.2accounted for only 0.64% of the PM10.The FF had a high removal efficiency(99.98%)to the total fly ash particles.However

the removal efficiency of PM0.2 was only 99.88%

as the PMs with smaller particle size penetrate the filter and deposited on the surface more easily.The concentration of PMs with diameter larger than 2.5μm reduced in the WFGD system while the PMs with diameter less than 2.5μm(particularly around 0.5μm)increased due to the ultrafine PM aggregation as well as new PM formation from gypsum slurry entrainment.