A conveyor comprising a support frame, an inclined tube mounted to the support frame, a hopper at a lower end of the tube for receiving material, a spout at an upper end of the tube for discharging the material, a running plate extending inside the tube, and a cleated belt, supported by the running plate, that conveys the material from the hopper to the spout through the tube. The cleated belt comprises a plurality of spaced-apart cleats and wherein each cleat has a base extending transversely to a direction of travel of the belt and curved sides that curve upwardly and outwardly from the base.