Abstract:
The ram press is a manual device used to extract oil from oilseeds such as sunflower, sesame, groundnut and rapeseed. Seed and machine factors affect the efficiency of oil extraction. The influence of sunflower seed moisture content and percent foreign materials, size of choke opening and length of rest period at end of the stroke on oil recovery with the ram press was determined. Values of factors giving highest extraction efficiencies were moisture content of 5.62% (71.67%), 0% foreign materials (267.5%), 4 seconds rest period (67.88%) and a choke opening of 1.28 cm (68.42%). Oil recovery at different levels of these factors was significantly different at the 95% level. There was no significant difference in oil recovery at moisture contents between 4.29 and 9.11%. The percent foreign materials in the seed should not exceed 5% if a significant reduction in oil recovery is to be avoided. Oil recovery at 4 and 6 second-rest periods was significantly higher than at the other rest periods. At a choke opening of 1.28 cm oil recovery was significantly higher than at other choke openings.
