Different types of mechanical air filters have different designs

1, flat filter contains the whole medium in the same plane.  This design allows the filter area to be consistent with that of the filter medium.  

2, select the effect of folding filter, will add additional filter medium to reduce the pressure drop through the filter medium.  This allows the air filter to be more efficient at certain pressures.  The efficiency of medium efficiency folding filters can range from coarse efficiency G3 to high efficiency combined filter (HEPA).  

3, BagFilter, air through the filter medium made of small pockets.  BagFilter can be composed of one to twelve bags, and the number of added pockets is equivalent to adding the filter area of the filter medium.  As with medium-effect foldable filters, the added filtration area of the BagFilter reduces the velocity of the flow through the filtered medium, thereby increasing filtration efficiency at specific pressures.  

4, automatic rolling air filter is generally selected low efficiency of the medium, the medium is fixed on the drum.  When the filter material is required to be replaced, the medium is dragged by the motor to provide a new filter for the ventilation system.  

Three forms of mechanical air filter filtering:  

Inertial shock: When micron particles float in the air and move around the fiber, escaping from the air (due to micron particle inertia) and colliding with the fiber.  

Interception: Interception occurs when large dust particles, due to their size, collide with fibers in the filter through which the air passes.  

Diffusion: Diffusion occurs when the disordered (Brownian) motion of micron particles brings micron particles into contact with the fiber.  

Electrostatic filters are different from electrostatic precipitators, which require a plug and a plate to attract and trap dust particles.  Electrostatic filters contain fibers that are enhanced by static electricity and attract particles to the fibers in addition to retaining them.  Electrostatic filters rely on charged fibers to significantly increase filter efficiency.