The roles of Bag filters

The main roles of the bag filters include the following:
(1) Screening role. Dust-laden gas through the filter bag, filter bag fiber gap or the space between the adsorption on the surface of the filter bag dust is greater than the gap of the diameter of the dust separation down, called the sieving effect. For the new filter bag, the gap between the fiber is very large, dust collection effect is not obvious, only after a period of time, in the filter bag surface accumulation of a certain thickness of the dust layer, screening effect is obvious, dust collection efficiency is high.
(2) Inertia role. Dust gas through the filter bag fiber, the air flow around the fiber, large particles of dust due to inertia still maintain a linear motion hit the filter bag fiber, which was captured. The greater the diameter of the dust particles, the greater the inertia.
(3) Diffusion role. When the particle size of the dust particles is too small (below 0.2μm), Brownian motion, like the thermal motion of the gas molecules, is created, which increases the chance of contact with the surface of the dust and the filter bag, making it easier to capture.
(4) Adhesion role. When the dusty gas close to the filter bag, the small dust still with the air with the movement, if the dust radius is greater than the dust center to the edge of the filter bag, the dust will be the filter bag adhesion and capture, the smaller filter bag gap, the more obvious the role of this adhesion.
(5) Electrostatic role. Dust particles collide with each other to produce electricity and produce static electricity. If the filter bag is an insulator, it will also be charged. When the dust and filter bag with the opposite charge, the dust was adsorbed on the filter bag, thereby enhancing the efficiency of bag filter. Conversely, when the dust and filter bag with the same charge, but also reduce the dust collection efficiency. The general electrostatic effect is only shown when the particle size is less than 1 μm and the flow rate of the filter gas is low.