Abstract: A combine harvester has a threshing mechanism with a rotor and a plurality of concaves for threshing grain and cleaning apparatus for removing chaff from the threshed grain. The cleaning apparatus includes a rotor pan arranged below the concaves and a sieve arranged below the rotor pan. A fan is arranged to blow air into an inlet. A duct has a wall defining a passage in fluid communication with the inlet, a first exhaust and a second exhaust in fluid communication with the passage. The first exhaust is arranged to direct a first portion of airflow on the sieve and then up toward the underside of the rotor pan. The second exhaust is located above the rotor pan and arranged to direct a second portion of airflow between the top of the rotor pan and an underside of the concaves.

Abstract: A cascade pan may be disclosed. The cascade pan may comprise a surface located proximate a fan having an exhaust. The surface may comprise an upper portion arranged above a lower portion. The surface may define a plurality of openings and may be arranged to receive a portion of air exiting the exhaust.