Screw Conveyor

A screw conveyor at Kandos Cement Works runs along the underside of one of the mill bays, carrying material laterally between two points in the cement-making circuit. The conveyor is housed in a long steel trough with a bolted lid, hung from the structural steel above on threaded rods. The drive motor at one end sits on a small bracket, coupled to the screw shaft through a reduction gearbox. Cement dust has settled on the upper surfaces of the trough and along the joins where the access plates seat against their gaskets. The trough is darkened from years of operation. Light from a clerestory window above falls across the run, picking up the line of bolt heads down the lid.

A screw conveyor is one of the standard means of moving powdered material short distances in a plant of this kind. A helical screw inside a closed trough rotates, dragging the material along the trough toward the discharge end. The system is dust-tight, simple to maintain, and well suited to cement-making circuits where airtight handling matters. Kandos Cement Works ran many of these conveyors across its 95-year operational life. The plant closed in September 2011 and the screws have been still since. Most of the conveyor housings remain in place; the higher-value motor and gearbox components in some bays were removed in the decommissioning phase after closure.