Dry ESPs remove dust from the collection electrodes by vibrating the electrodes through the
use of rappers. Common types of rappers are gravity impact hammers and electric vibrators. For a
given ESP, the rapping intensity and frequency must be adjusted to optimize performance. Sonic
energy is also used to assist dust removal in some dry ESPs. The main components of dry ESPs are an
outside shell to house the unit, high voltage discharge electrodes, grounded collection electrodes, a high
voltage source, a rapping system, and hoppers. Dry ESPs can be designed to operate in many different
5.2-8
stream conditions, temperatures, and pressures. However, once an ESP is designed and installed,
changes in operating conditions are likely to degrade performance