In dry filtration a filter fabric is used as a medium to collect the offending particles like particulate dust, smoke, and gaseous fumes, so as to keep them from being emitted into the atmosphere. In the normal filtering mode, dust laden gases enter the filter housing at low velocity around the top of the bag area. The gases pass down the outside of the bags and through the bag filter cloth. The cleaned gases then pass upwards inside the filter bags to the clean gas chamber at the top of the unit. After a period of time, dust build –up on the outside of the bags will impair their filtration efficiency and hence a cleaning cycle is initiated by the timer control. In this mode a short burst of compressed air is directed down the inside of the bag to induce a flow of gas in the opposite direction to the normal flow, thus dislodging the dust form the outside of the bags.
Additionally the compressed air generates a shock wave in the bag which also assists in dislodging dust. As the incoming dust laden gases within the unit are moving in a downward direction, the dust dislodged from the bags also moves in this direction until it reaches the dust collection hopper. There it settles in the comparatively still air conditions within the hopper.
The substrate used for dry filtration process include Nomex , Glass Cloth, Polyester needlefelt , PPS and p84, all which can have a variety of finishes added to aid dust release, be moisture repellent or reduce acidic / alkaline attack.
Very high filtration efficiency (solids emission levels
Dry handling and storage of the collected solid dust particles and eventual validating of the collected dust (no waste water),
Low energy consumption,
High efficiency dust collection with low maintenance
Optimised gas flow distribution system
Multi-compartment concept allows flexibility of system design
Use of standard components minimises costs
Improved Filter Bag and Cage design
Venturi fitted to Bag Cage improves pulse cleaning
Intelligent control system reduces power consumption