Development of A Segmented - Screw Type Expeller for Production of Virgin Coconut Oil

A continuous type expeller, which is presently pending a patent, was developed to extract virgin quality coconut oil. Segmented-screw helical ribs with stationary pegs fitted to the screw barrel facilitate forward movement of material without clogging and generating heat. A movable pressure cone fitted at the discharge end provides sufficient pressure inside the screw barrel.

Optimum performance of the expeller was at 33.6 RPM of the screw shaft and 10-12 liters of virgin coconut oil in an hour with a 60% oil yield was realised. Sieve analysis of press cake showed that the material was subjected to extensive shearing while compressing, which leads to high oil recovery. Power requirement was 1.38 kW.

Since the expeller is operated by a single-phase 2HP motor, it can be used to produce virgin quality coconut oil at cottage level as a self employment. Due to simplicity of the expeller, it can be fabricated in a medium level workshop.