Mechanical-pneumatic device to meter, condition, and classify chaffy seed

An apparatus and method for conditioning and/or classifying seed is disclosed. The apparatus includes a seed conditioning/classification unit having an acceleration conduit and a convexly curved Coanda surface provided adjacent to the conduit at its outlet, curving upwardly therefrom. As the crude particulate feed stream is discharged from the outlet, it is conditioned by the Coanda effect into a first outlet stream of entraining gas and lightweight extraneous materials, which is channeled approximately along or parallel to the Coanda surface, and a second stream of relatively heavier materials such as seeds, which is expelled approximately parallel to the central axis of the conduit at the outlet. Seeds which are expelled from the conduit are also classified by momentum discrimination.