A power-operate corn sheller was constructed to investigate the effect of
corn moisture content, concave clearance and cylinder rotating speed on the broken
and whole corn kernels percentages, total losses percentage as well as shelling
efficiency and sheller productivity (kg/h) .The experiments were conducted at four
levels of kernels moisture content of 12, 15.5 , 19.2 and 23 %, three concave
clearances of 30 , 40 and 50 mm and four cylinder rotation speeds of 450,500,550
and 600 rpm, (9.4 , 10.5, 11.5 and 12.6 m / s). The results indicated that decreasing
the cylinder speed and increasing the concave clearance tends to reduce the
percentage of kernel broken and shelling efficiency and increase the percentage of
kernel whole and total losses at all kernels moisture contents. The minimum percent
of kernel broken of 6.5% and the highest kernel whole of 93.5% were found at
concave clearance of 50 mm, cylinder rotating speed of 450 rpm (9.4 m/s) and kernels
moisture content of 15.5%. However, the least percent of kernel losses of 4.6% and
the highest percent of shelling efficiency of 95.4% were recorded at concave
clearance of 30 mm, cylinder rotating speed of 600 rpm (12.6 m/s) and kernels
moisture content of 12%. The results also revealed that the highest machine productivity of 215.5 kg/h
was obtained at concave clearance of 30 mm, cylinder rotating speed of 600 rpm
(12.6 m/s) and kernels moisture content of 12 %.