DDF- large bag filter is widely used in steel mills, smelting plants, cement plants, carbon black plants, power plants and other enterprises smelting, crushing, screening and combustion of soot generated by purification and recovery. DDF- large bag filter is an effective equipment to protect the operator and people's physical and mental health, the growth of crops, the wear and tear of mechanical equipment, the pollution of the social environment and the recycling of useful dust. Dust bag arrangement number 1000m2 is the number of rows in the layout of the 3000-9000m2; 2W2 is the number of rows in the 2W4W2 layout. 1800m2 is the number of rows in the layout of the 10000m2; 3W3 is the number of rows in the layout of the surrounding channel. W express access channel. The entrance temperature of 729 and 734 polyester cloth