Particulate Matter Emission Characteristics and Removal Efficiencies of a Low-Low Temperature Electrostatic Precipitator

摘要

The low-low temperature electrostatic precipitator (LLT-ESP) has been developed recently to improve the performance of traditional low temperature electrostatic precipitators. In this study, the particulate matter emission characteristics and removal efficiencies of were investigated on an LLT-ESP. Filterable particulate matter (FPM) was tested according to ISO standard 23210-2009, and condensable particulate matter (CPM) was tested according to U.S. EPA Method 202. The LLT-ESP showed excellent removal efficiency for FPM, with total FPM removal efficiencies of more than 99.9%. The removal efficiencies of FPM increased with the rising particulate diameter; for FPM2.5, removal efficiencies ranged from 96.5 to 98.2%. The LLT-ESP also showed remarkable removal efficiencies for CPM, with CPM removal efficiencies of more than 60.9%. The removal mechanism of CPM in the ESP was different from that of FPM. After the LLT-ESP, the quantity relationship between FPM and CPM reversed. For further reduced emission of PM for coal-fired power boiler units, more attention should be paid to the control of CPM. The load of the unit showed significant effects on CPM. CPM was generated more in lower unit loads for incomplete combustion of coal, and the organic fractions accounted for more than 65% of total CPM in the inlet flue gas of the LLT-ESP. SO42- was the main contributor of anions, and Cl- took second place. Na+ and Ca2+ were the main contributors of metal ions.