Fabric filters inertial impaction

Types of filters. Two broad general classes of filters are commonly used (1) depth filters, which normally employ inertial impaction and Brownian movement as collection mechanisms and which are often discarded or cleaned with a liquid when they become ditty and (2) fabric (or bag) filters, which build a bed of solids that acts as the filter medium and which is normally cleaned mechanically at frequent intervals (simitar to Hquid-anEd cake filters). 

It is widely accepted that the fibres in the filter fabric capture the dust particles by one of several mechanisms, these being identified as inertial impaction, interception,diffusion (Brownian motion) and electrostatic forces (see Rg. 7.1). Inertial impaction occurs when particles are of sufficient mass and bulk as to leave the gas stream and make a direct impact on a fibre in the filter. 

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