CASE STUDY OF RECURRENT FAILURE OF WORM SCREW IN LOCALLY FABRICATED PALM KERNEL OIL EXTRACTOR; DESIGN, AND RECOMMENDATION OF AN IMPROVED WORM SCREW

ABSTRACT
In previous processes, machine press was used to produce oil and wine. Currently screw-type machine comprising continuous screws is used. However, several failures are associated with the worm screw due to a range of different factors- moisture content of palm kernel seed, friction, pressing method, etc. Consequently, the adverse effect has led to decline in effective performance of the extractor; low efficiency in oil production, etc. Therefore, this project is focused on improving worm screw in a locally fabricated palm kernel oil extractor to be used for a longer period of time before maintenance repair/replacement. The study aimed at investigating the recurrent failure of Worm screw in locally fabricated Palm Kernel oil extractor and designing an improved worm screw.
The methodology in this project is case study. The area of study is the palm kernel Oil factory located at 2nd East Road, Benin city with focus on the worm screw and its failure. The instrument for data collection included the use of digital camera, obtrusive observation and unstructured interview. The design consideration included material selection, fabrication methods and heat treatment processes.
The study revealed the following findings: The material of choice used for the fabrication of worm screw for locally fabricated palm kernel oil extractors is mild steel; Machining the worm screw lowers the failure rate of worm screw and Annealing and carburizing of the worm screw improves its toughness and hardens its surface against wear. Conclusion was made that the recurrent failure in worm screw of palm kernel oil extractors is reduced in the design concept of an improved worm screw based on the findings. The following recommendations were made that Machining method should be adopted in fabricating the worms screw; Heat treatment process should be used to improve the strength, toughness of the core, hardness of the surface and Manufacturers should use better alloys of Steel suitable for efficient oil extraction processes.