Abstract: A curved blower exhaust conduit, delivering an air stream carrying pulverized or granulated entrained solids to a substantially sealed cargo chamber enclosure of fixed volume, is provided with a pressure relief vent mounted at an “inner” peripheral region of the curved conduit having a smaller radius of curvature than the outer peripheral region of the conduit, thereby connecting the interior of the curved conduit to the external atmosphere at a point where the majority of entrained solids are carried adjacent to the outer peripheral region by the air stream.