Successfully engineering a dust disposal system for reliability and efficiency is both an art and a science. Air-Cure has mastered both disciplines and has exceptional experience creating custom dust disposal systems for a wide variety of applications.
A pneumatic conveying system transfers fugitive dust through an enclosed horizontal or vertical conveying line (typically a 4-6 inch pipe for distances up to 1500′) using pressure differential and the flow of air supplied by a blower or compressor. This gives the ability to remove dust from the dust collection system and separately convey the dust to a plant silo, yard silo, or crusher surge bin where a mechanical separator (cyclone) can deposit the dust and vent the conveying air to a local dust collector.
The pneumatic transport will convey the surge of dust to an appropriate discharge point other than the conveyor belt which eliminates both re-entrainment and “end of run purge” dusting. Pneumatic transport also allows collectors to be located at grade or locations for easier maintenance access and to be more economical, eliminating costly structural supports to position collectors above conveyors for gravity spouting.
Typically used with fine coal dust, agglomeration is a mechanical process that produces a mixture which resembles a rich black soil and will ball when compressed in one’s hand, but will fall apart when released. This agglomeration process can be used below one filter or in combination with pneumatic transport so one unit can serve several dust collectors to reduce the airborne dust concentration in the silo or area receiving the coal dust. Agglomeration also offers benefits when the coal is going from car dump to outside stockpile where it is very difficult to prevent dispersion of the coal dust in windy weather. The drawback to agglomeration is the greater complexity. Dust and water must flow consistently into the mixer to provide a consistent product. Since flow from a dust collector is not consistent, a surge hopper with sufficient capacity for the “end of run purge” must be incorporated into the equipment layout with associated pressure relief venting, fire detection, suppression, and level indication. Additionally, agglomeration has to be in a heated building for freeze protection and should not be placed on an empty conveyor belt or conventional screw conveyor.