It works by injecting the flow of material to be separated into a room containing the rising air column. In the separation chamber, the air dragging on the objects provides a upward force that resists the force of gravity and lifts the material to be separated. As the air friction depends on the object size and shape, the objects in the moving air column are vertically lined up and can be separated.
Air -classes are widely used in industrial processes where large volume mixed materials with different physical properties should be separated quickly and efficiently. It is useful for air -class, cement, air pollution control, food processing, pigments, pharmaceuticals, cosmetics or chemical industries. Such an example is in the municipal recycling centers where various metal, paper and plastic species are mixed and must be separated before further operations.