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Preliminary Design on Screw Press Model of Palm Oil Extraction Machine

The concept of the screw press is to compress the fruit bunch between the main screw and travelling cones to extract the palm oil. Visual inspection, model development and simulation of screw press by using Solidworks 2016 and calculation of design properties were performed to support the investigation. The project aims to analyse different design of screw press which improves in reducing maintenance cost and increasing lifespan. The currently existing of screw press can endure between 500 to 900 hours and requires frequent maintenance. Different configurations have been tried in determination of best design properties in screw press. The results specify that screw press with tapered inner shaft has more total lifespan (hours) compared existing screw press. The selection of the screw press with tapered inner shaft can reduce maintenance cost and increase lifespan of the screw press.

The palm farmers of Bangladesh are suffering for want of an extraction machine. Therefore, a research was undertaken to design and develop a manually operated palm oil extraction machine at the department of Farm Power and Machinery, Bangladesh Agricultural University. It is a press type machine. A screw leads a piston manually in a perforated cylinder to press the mesocarp (pulp of palm fruit) to extract oil. The volume of the cylinder of the machine was found 0.03 m3 and maximum 20 kg fruits can be accommodated at a time. The amount of crude palm oil press at full capacity of the machine was found 8 kg/hr., which is higher than any manually operated extracting machine available in the market. The crude oil extraction efficiency of the machine without palm kernel was also found satisfactory. Application force on screw can be increased by increasing the length of the handle and number of persons according to filling condition of the cylinder. The machine was developed with locally available materials for having low purchase price and smooth repair and maintenance. So that, it will be easily affordable to the palm farmers of Bangladesh. The developed machine will solve the burning need of palm farmers in Bangladesh.

One of important sources of biomass-based fuel is Jatropha curcas L. Great attention is paid to the biofuel produced from the oil refinery extracted from the Jatropha curcas L. seeds. A mechanised extraction is the most efficient and feasible method for oil extraction for small-scale farmers but there is a need to extract oil in more efficient manner which would increase the labour productivity, decrease production costs, and increase benefits of small-scale farmers. On the other hand innovators should be aware that further machines development is possible only when applying the systematic approach and design methodology in all stages of engineering design. Systematic approach in this case means that designers and development engineers rigorously apply scientific knowledge, integrate different constraints and user priorities, carefully plan product and activities, and systematically solve technical problems. This paper therefore deals with the complex approach to design specification determining that can bring new innovative concepts to design of mechanical machines for oil extraction. The presented case study as the main part of the paper is focused on new concept of screw of machine mechanically extracting oil from Jatropha curcas L. seeds.