Reduction of Rapping Losses to Improve ESP Performance

Abstract

The need to reduce emissions of particulate matter, NO _x , SO _x , VOC, and most recently CO₂ to address Global Warming, is becoming a worldwide concern. Electrostatic Precipitators (ESPs) have been predominantly used for many years to collect particulate matter from the gas stream of power plants and industrial processes. Unfortunately when the collecting electrodes are cleaned a portion of the precipitated material typically reenters the gas stream and exits the ESP. The amount of reentrainment losses from ESPs may not be suitable to meet lower emissions limits for particulate matter in the future.

Alstom Power Systems (APS) has developed a new technique to reduce the rapping losses from an ESP. This paper presents the key aspects of design and collected information from the current operating units in Guatemala and Finland. The new design is a cost effective approach to address this well-known problem for ESPs. With future development and refinement of the technology it may be possible to reduce the particulate emissions after an ESP to the Near Zero Emissions target being discussed by regulators from e.g. coal-fired power plants.