Fine Coal Ash Collection Efficiency of Advanced Low Temperature Electrostatic Precipitator on Pulverized Coal Combustion

Electrostatic precipitator (ESP) is a major dust collection equipment in pulverized coal combustion boiler in Japan. As the environmental influence of fine particle such as PM2.5 in the atmosphere is focused recently, the improvement of the collection efficiency of fine particle on ESP is desired. An advanced low temperature ESP operated under 363 K has been used recently because of its availability for high electric resistivity coal ash. In this study, the separation characteristics of fine coal ash particle by the control of operation condition on advanced low temperature ESP in a pulverized coal combustion boiler is investigated. It is estimated that the fractional collection efficiency of advanced low temperature ESP shows a minimum value at the particle size in the range 0.5 to 1.0 μm. The collection efficiency of fine particle under 2.5 μm is improved by the increase of current density of ESP and the control of gas flow pattern in ESP is one of the effective method for the improvement of the collection efficiency of ESP.