For average and thin purification of air filters in which dusty air is passed through the porous filtering materials are widely used. If the size of particles of dust is more than a size of time of the filtering material, the superficial (net) effect of a pyleulavlivaniye works. If the size of particles of dust is less than a size of time, dust gets into the filtering material and settles on the particles or fibers forming this material. Such process of filtering is called deep.
fans it is the pressure-blowing cars creating a certain pressure and employees for movement of air at losses of pressure in a ventilating network no more than 12 kPas. Are the most widespread axial and radial (tsentrobezhna fans.
The axial fan represents the scapular wheel located in a cylindrical casing. At rotation of a wheel air under the influence of shovels moves in the axial direction. Advantages of axial fans are simplicity of a design, possibility of effective regulation of productivity by means of turn of shovels, the big productivity, reversibility of work. Rather small size of pressure and the increased noise belong to shortcomings.