The dust collector bag is the core element of the filter type dust collector. Usually the cylindrical impulse type dust collector bag is suspended in the dust collectors vertically. Dust gas enters he dust collector bag from the air inlet and the passage board, making most big dust particle filtered out into the dust hopper directly by inertia. When dust gas reaches the filtering area of the box with dust collector bags, most dust is captured on the outer surface of the dust collector bags,and the gas flows into the pocket through filter media,then purified gas discharges from the ourlet .The cage inside the pocket is used to support and prevent the pocket to collapse while it is helpful to remove and redistribute the dust cake.