Cracked mixture from the nut cracking process is fed into a vertical winnowing column, where light shell and particles are lifted upward by air stream induced by a fan. The light shell and particles are lifted upward through air ducting and into the air cyclone, where the light shell and particles drop to the bottom and exits through an airlock. The air is discharged from the top of air cyclone and exits to the atmosphere through the fan outlet. The heavier shell and kernels drop back at the expanded section into a bypass column leading to the hydrocyclone or claybath. Large kernels and uncracked nuts fall downward into the main winnowing column where a vibrating trough, separates the uncracked nuts to be recycled and the kernels discharged into kernel silo for drying. An attempt is made in this paper to present the salient features of a modular type of pneumatic separation system to separate kernel from cracked mixture.