Patent 8172088 was granted and assigned to Laitram (company) on May, 2012 by the United States Patent and Trademark Office.
Apparatus and method for separating lightweight waste from product with cyclic pulses of air. An air separator includes a blower duct directing air upward through product conveyed on a foraminous conveyor. A pair of counter-rotating vanes in the blower duct cyclically open and close to establish a pulsating air flow in the center of the duct across the width of the conveyor. The pulsating air flow lifts lightweight waste from the product and blows it through a vertical duct above the conveyor to waste separation chambers for separation and disposal.