Particulates - Control Technologies

Control Technologies

Particulate matter emissions are highly regulated in most industrialized countries. Due to environmental concerns, most industries are required to operate some kind of dust collection system to control particulate emissions. These systems include inertial collectors (cyclone collectors), fabric filter collectors (baghouses), wet scrubbers, and electrostatic precipitators.

Cyclone collectors are useful for removing large, coarse particles and are often employed as a first step or "pre-cleaner" to other more efficient collectors. Fabric filters or baghouses are the most commonly employed in general industry. They work by forcing dust laden air through a bag shaped fabric filter leaving the particulate to collect on the outer surface of the bag and allowing the now clean air to pass through to either be exhausted into the atmosphere or in some cases recirculated into the facility. Common fabrics include polyester and fiberglass and common fabric coatings include PTFE (commonly known as Teflon©). The excess dust buildup is then cleaned from the bags and removed from the collector. Wet scrubbers pass the dirty air through a scrubbing solution (usually a mixture of water and other compounds) allowing the particulate to attach to the liquid molecules. Electrostatic precipitators electrically charge the dirty air as it passes through. The now charged air then passes by large electromagnetic plates which attract the charged particle in the airstream collecting them and leaving the now clean air to be exhausted or recirculated.