Experimental Investigations of Factors Affecting the Performance of Electrostatic Precipitator in Emission Control from Coal-Fired Power Plants

摘要

Electrostatic precipitator (ESP) is one of the most widely used particulate collection devices. In order to folly explore the potential of this ubiquitous pollution control equipment, a five-field ESP has been custom-built and installed for CANMET=s pilot scale Vertical Combustor Research Facility (VCRF). This paper describes a series of combustion experiments conducted at CANMET with an eastern bituminous coal and presents experimental measurements on the efficiency of the ESP in removing fine particulates and mercury across the ESP under various operating conditions. The results showed that, with all five fields active and under automatic voltage control, the ESP removed 98 - 99% of total fly ash. The efficiency dropped to 93% when only three fields were active. In addition, mercury speciation at the inlet and outlet of the ESP was conducted and these results showed that, as flue gas passed through the ESP, a significant part of elemental mercury was converted to oxidized form without any additives. This conversion is tentatively attributed to the relatively high chlorine content of this coal.