Abstract: A dust collector of the type wherein a main body of the dust collector includes one or more filter elements 11 which are permeable to air but not to airborne particles above a predetermined size, a live air zone 13 below the filter elements 11 and a main air inlet port 14; a vacuum being generated on that side of the filter elements 11 opposite the live zone 13 which thereby induces a pressure differential across the filter elements 11 whereby air and entrained particulate matter is drawn through the main air inlet port 14 into the live air zone 13 within the main body 17; the dust collector further including particulate matter guiding means 18 (in one particular form being in the form of a tubular shell) for changing the direction of movement of the entrained particulate matter in the main hopper immediately after it enters the main body from the main air inlet port 14; the particulate matter guiding means comprising a duct member 18, having at least one change in cross-sectional area therein from a smaller