Modification of a Coconut De-husking Machine

Abstract

Contrary to the immense economic importance of coconut for both industrial and domestic uses, de-husking of the fruits after harvesting constitutes the most difficult and dangerous operations during processing. Modification of a manually operated coconut de-husking machine was carried out. The machine was designed and fabricated using locally sourced materials. It consists of the supporting frame where the machine components were mounted. The de-husking unit consists of two steel pipe rollers with spikes and shafts. The driving and driven roller shafts are mild steel rods supported at both ends by ball bearings. Two spur gears were used with the same pitch circle diameters and number of teeth respectively. Flywheel was also incorporated to produce high torque. When the handle is rotated, power is transmitted through the gearing arrangement to the rollers with plurality of spikes and rotate them in opposite directions toward the centre thereby causing both the gripping and tearing of the husk when the coconut is placed in between the rollers. Different sizes of coconut fruits were loaded at different times on the machine and the time taken for each fruit to be de-husked was recorded. A total of 20 fresh nuts were tested. The performance evaluation shows that the average efficiency of the machine was 85% while the average capacity is 65 coconuts per hour which is higher compared to the existing coconut de-husking machine. On the other hand, the percentage number of distorted coconuts was 10% which is lower compared to the existing coconut de-husking machine. Hence it is recommended for use by farmers.