Design fabrication and testing of a cashewnut decorticator

Abstract

A manually operated cashewnut decorticator is designed, developed and evaluated. The major parts are top blade assembly, and linkage assembly, 2-blade bottom assembly, and linkage assembly. The whole assembly is fixed on a work table.

The steamed cashewnut is placed manually between the top and bottom blades. Upon pressing the pedal the top and bottom blades slit the two long sides of the nut. The two bottom blades are then opened wide with a cam splitting open the shell in to two halves. The kernel is released from the shell. The efficiency in decorticating is 88 per cent while the percentage of the number of kernels damaged is 12. The capacity of the machine is 900 nuts/h.

The important physical properties of nuts were also studied. It is kidney shaped. Its mean size is 32.40 mm long, 24.60 mm wide and 17.60mm thick. The average kernel size is 26.00 mm long, 17.20 mm wide and 12 mm thick. The average thickness of the shell is 3.20 mm. The average weight of the nut is 7.0 g while that of the kernel is 2.1 g. considering its performance the mechanism is sound. It is recommended for further studies and modifications.