The granular material to be separated is taken to the table deck through an adjustable spring-actuated flap. The deck surface is covered by a wire mesh, through which a steady and adjustable air flow is aspirated.
The combined effect of the vibrating movement and of the air passing through the deck causes the flow of material to be arranged in layers. The heavy admixtures sink towards the bottom and are moved to the highest point of the table deck surface (stone outlet) by means of contact with the rough deck covering