The filter bag is the heart of the bag filter. Usually, the cylindrical pulse filter bag is suspended vertically in the dust collector. Dust-containing gas enters the dust collector through the air inlet and passes through the deflector of the ash hopper. Some large particles of dust in the gas are separated by inertial force and directly fall into the ash hopper. Dust-containing gas enters the filtering area of the filter bag of the box, most of the dust is trapped on the outer surface of the filter bag, while clean gas enters the filter bag through the filter material, and the purified gas enters the upper box through the filter bag mouth, and then is discharged from the air outlet. The cage inside the filter bag is used to support the filter bag, prevent the filter bag from collapsing, and help to remove and redistribute the dust cake.