Generally, coconuts are dehusked manually using either a machete or a spike. These methods require skilled labour and are tiring to use. Attempts made so far in the development of dehusking tools have been only partially successful and not effective in replacing manual methods. The reasons quoted for the failure of these tools include unsatisfactory and incomplete dehusking, breakage of the coconut shell while dehusking, spoilage of useful coir, greater effort needed than manual methods, etc.
The present work involved the design, development and testing of a coconut dehusker which overcomes the drawbacks of the previously reported implements. The design and developmental stages called for a closer look at the magnitude and direction of the dehusking forces and their generation mechanisms.
Details of a simple, sturdy and efficient hydraulic dehusker unit, financially beneficial to labourers and producers, are given here. Comparative assessment of this unit in relation to those reported in the literature is provided.
Test results and assessment of the present unit in both laboratory and field conditions are also reported. Safety aspects are incorporated. The unit can dehusk about 70 coconuts per hour compared with about 40 nuts per hour from a skilled worker using the spike method. It can be operated by unskilled labourers. Cost benefit analysis indicates that it should be commercially viable.
This coconut dehusking machine peels off the coconut husk from coconut fruit to obtain dehusked coconut fruit via mechanical controlled dehusking devices. The coconut is placed on the holder in vertical position.
The holder is moved up by the foot operation mechanism. The top assembly which comprises the gripper pokers held vertically with link mechanism and is pivoted to the coconut body. The top assembly movement effects the pokers to move in the downward slide to poke into the coconut and at certain depth will make the pokers to move apart at 45 degree by the pusher link mechanism to tear apart the husk with force.
The foot operated holder can be adjusted to the required height by the height adjuster. The foot lever is operated to continue the pumping till the mechanism is pulled down to its lowest position till the coconut is de-husked from the fruit. The foot operation is returned to the original position and also the top assembly is lifted back to its original position by the release valve operation of the pump and cylinder facilitating the removal of the coconut. The main parts involved in the project are hydraulic pump, cylinder, coconut holder mechanism, height adjusting knob, and poker arms.
This machine is useful to the coconut estates and co-operatives, coconut growers and coconut processing factory. The machine can provide faster work rate and less human interaction. This machine is expected to increase the coconut production, hence an additional income to coconut growers. It is useful to the coconut growers by many ways. It does not require direct human force as in normal methods because in this hydraulic pump and cylinder is used to enhance the force at the head of the coconut to put pressure on poker assembly. Also the coconut of any size and shape can be dehusked easily. It is easy to operate, does not need skilled labour, rapid, safe operation and simple maintenance. It can be easily assembled and disassembled and it can be carried from one place to another.