Bag Filter is divided in three parts i.e. top part called as Plenum (Clean air chamber), which is heart of the bag filter operation; middle one is called as Housing/casing (Dirty air chamber) and bottom part is called as Hopper. The plenum is separated from the housing by the bag plate/tube sheet where the filter bags and cages (the filtering elements) are supported. The Bag Filter unit is a continuous self- cleaning dust filter, capable of removing dust particles as small as submicron size from gaseous and dust streams.

Bag filter construction is simple and does not have any moving parts, Pulsejet cleaning mechanism with the help of compressed air results into high dust cleaning efficiency.

Dust laden air enter the Bag Filter at housing under suction or pressure. The air travels through the filter bags which retains the dust particles on the surface of the bag and the clean air passes through filter bags to the plenum leading to the outlet of BF due to the suction effect created by centrifugal ID fan.

Dust collected on the outside of the filter bags causes an increase in the pressure differential between the dirty and clean air sides of the bag filter. To control the pressure differential across the bag filter, a sequential timer actuates a series of normally closed pulse valves at preset intervals causing them to open. A momentary rush of high-pressure air (5-7 bar g) flows from the compressed air header to the blow tube and is expelled from the blow tube through venturies at a high velocity (primary air flow). Air from each ventury induces a secondary airflow. The combined effect of the primary and induced secondary air causes an instantaneous pressure rise on the clean side of the filter bags, causing a reverse flow of air through the filter bags, thus dislodging the dust

Above cleaning cycle causes the dust particle to fall down in the collection hopper. Collection hopper store the collected dust temporarily. The dust is discharged from hopper bottom through RAL or Screw conveyor.