Electrostatic Precipitator Pilot Studies on a Cement Plant Clinker Cooler

Some pilot studies into the removal of particulates from the exhaust of a cement plant clinker cooler are described. A two-stage electrostatic precipitator was employed, consisting of a conventional plate-wire precipitator closely followed by a three-stage grid-type precipitator, to handle 12 000 actual cubic feet per minute (acfm) of exhaust gas. To offset the high electrical resistivity of the clinker dust, moisture was added by spraying water directly onto the clinker bed in order to alleviate the problems caused by back corona. Overall collection efficiencies in excess of 90 percent were achieved, and in excess of 40 percent by the grid precipitator section alone. It is estimated on the basis of previous experience that, by using a twelve-stage grid precipitator section, overall collection efficiencies greater than 99 percent are possible. Overall treatment length would be appreciably less than for a conventional plate-wire precipitator having the same efficiency.