Abstract: A dust collecting installation for collecting airborne dust adjacent to a moving web. An elongate duct extends transversely to the direction of movement of the web and is positioned adjacent to the web. The duct is shaped and positioned so as to form an opening into the duct that receives at least a proportion of a layer of dust laden air adjacent to and moving with the web surface, and dust laden air is in turn withdrawn from the duct. The duct is positioned and so shaped that air flow into the opening is augmented by a jet of air generated where the moving surface converges with and comes into contact with a surface of a roller which the web passes over and contacts.