Behavior and model of grain separation for a small axial flow maize shelling unit

Abstract

Shelling and grain separation by a small axial flow maize sheller is influenced by the performance of both the maize shelling and cleaning units. For this study, the shelling and grain separation behavior were examined in a mini-maize grain separation unit. Concave rod clearance (CR) had the most impact on the effectiveness of grain separation. Concave rod clearances 10, 20 and 30 mm were selected as test parameters. Cumulative grain separation in a small axial flow maize shelling unit was analyzed in three zones, the feeding zone, the second and third zones, where the last two zones were separated zones. Test results indicated that when CR was increased, cumulative separation of grain, husks and cobs increased along the length of the shelling unit. These parameter relationships were represented using second-degree polynomial equations. An optimal shelling model for a small axial flow maize shelling unit was created. The function, S(l), represented cumulative grain separation as a function of separation length (l). The results from five shelling models indicated that predicted shelling parameters using Caspers’s model for both the feed rate and rotor peripheral speeds was the most satisfactory, with lowest root mean square error (RMSE) and highest coefficient of determination (R2).

Keywords

• axial flow
• maize shelling
• concave
• grain separation