Fabric filter collectors, Baghouses
Fabric filter collectors, or Baghouses, separate particulate from gas stream by causing the particulate to pass through a filtering media. The gasborne particulate is intercepted by the fibers of the filtering media, by the particulate already present on the media surface, or both. To prevent excessive pressure drop as the particulate accumulates, these devices use various mechanisms to disengage the particulate from the media.
Typical applications and uses:
There are three basic fabric filter dust collector applications.
1) “Nuisance” venting of conveyors, transfer points, packing stations and so on — this dust is often sent to waste.
2) “product collection” venting of classifiers, crushers, storage bins, air (pneumatic) conveying systems, mills, and flash dryers. This dust is often recovered because it has value.
3) “process gas filtration” venting of spray dryers, kilns, power boilers, reactors and so on. The collected solids may or may not be returned to the process. This dust may or not be worth recovering but must be controlled for environmental or workplace health reasons.
Fabric filter collectors are also currently used for gas absorption applications wherein the fabric filter collector is preceded by a spray dryer, dry Venturi, ductwork injection system, or the bags are precoated with an adsorbent or absorbent. Sodium bicarbonate precoat, for example, has been used to remove gaseous SO2 from power boiler exhaust gases.