Effect of Operating Speed and Cob Size on Performance of a Rotary Maize Sheller

Abstract

The operating speed of rotary maize sheller was optimised for its operation at higher operating speeds in pedalling mode, by conducting a simulation study for three sizes of maize cobs at seven operating speeds. The shelling capacity and shelling efficiency of maize sheller for all categories of maize cobs increased curvilinearly with increase in operating speed up to about 70 rpm. The shelling capacity at a particular operating speed decreased with increase in the maximum diameter of cobs. Operating torque of rotary maize sheller for a given size of maize cobs decreased with increase in operating speed. On the other hand, the torque decreased with decrease in maximum diameter of maize cobs at a given operating speed. It was concluded that the operating speed of maize sheller should be 70 to 80 rpm for higher shelling capacity, shelling efficiency and lower operating torque.