Impurities such as solid particles and gaseous compounds are generated from the processes carried out in industrial production cycles. These increase the degree of pollution of the atmosphere. Air filtration systems allow the reduction of the polluting load within limits that not to cause damage to humans or to the environment, In order to select and size the most suitable filtration system it is necessary to identify the characteristics of the different pollutants emitted:
The figure shows the classification of impurities present in the air as the diameter of the polluting particles varies. The variability of the particle size, of the air speed through the filter and of the properties of the filtering material do not allow defining a single filtration mechanism equally effective for all pollutants.