Water filter. The Venturi scrubbers belong to the medium energy systems. They are made up from two basic elements: the Venturi, in which the contact takes place between the liquid and the air to be scrubbed; the cyclone separator where the air and the drops that have captured the dust are separated. Operating principle: the dusty air, extracted by a fan, passes through the orifice to the Venturi, where it is subjected to a great increase in speed, while the water, recirculated by a pump, is introduced in correspondence with the groove."