Bag filter, also known as filter dust collector, is a dry high efficiency dust collector that uses bag filter elements made of fiber fabric to capture solid particles in dusty gas. The principle of action is that the dust particles are intercepted by the inertial force and the fiber collision when the fiber is wrapped around the filter cloth. The fine dust particles (having a particle size of 1Lm or less) are constantly changed by the impact of gas molecules (Brownian motion). Since the gap between the fibers is smaller than the free path of the Brownian motion of the gas molecules, the dust particles collide with the fibers. Was separated. The working process is related to the weaving method of the filter material, the density of the fiber and the diffusion of the dust, inertia, occlusion, gravity and static electricity, and the cleaning method. The filter cloth material is the key of the bag filter; the filter cloth with good performance should have good corrosion resistance, heat resistance and high mechanical strength, and good heat resistance, in addition to specific density and gas permeability. Fiber, its heat resistance can now reach 250 ~ 350 °C.