Abstract: A method for removing precipitate from a collecting surface of an electrostatic precipitator by rapping a point on the surface. Mechanical energy is applied a plurality of times with a rapper wherein the level of mechanical energy increases from one application of energy to another. Thus preciptate is removed from regions of the collecting surface progressively more distant from the energy application point. The time period between applications is selected to cause removal of precipitate from a region of the surface to be coincident with falling precipitate from regions above. The level of mechanical energy is controlled by applying to the rapper a sequence of full half-cycles of electrical energy followed by a single phase conduction cycle. The applied current is sensed and the duration of current application is adjusted to provide a predetermined energy level to the rapper. The polarity of the current is reversed to prevent magnetization of the rapper.

Abstract: A method for removing precipitate from a collecting surface of an electrostatic precipitator by rapping a point on the surface. Mechanical energy is applied a plurality of times with a rapper wherein the level of mechanical energy increases from one application of energy to another. Thus precipitate is removed from regions of the collecting surface progressively more distant from the energy application point. The time period between applications is selected to cause removal of precipitate from a region of the surface to be coincident with falling precipitate from regions above. The level of mechanical energy is controlled by applying to the rapper a sequence of full half-cycles of electrical energy followed by a single phase conduction cycle. The applied current is sensed and the duration of current application is adjusted to provide a predetermined energy level to the rapper. The polarity of the current is reversed to prevent magnetization of the rapper.