Theoretical analysis of force, pressure and energy distributions of bulk oil palm kernels along the screwline of a mechanical screw press FL 200
¹Czech University of Life Sciences Prague, Department of Mechanical Engineering, Faculty of Mechanical Engineering, Kamycka 129, CZ165 00 Prague, Czech Republic
²Czech University of Life Sciences Prague, Department of Material Sciences and Manufacturing Technology, Kamycka 129, CZ165 21 Prague, Czech Republic
The present study is a follow-up of the previously published study on the mathematical description of loading curves and deformation energy of bulk oil palm kernels under compression loading, aimed at determining theoretically the amounts of force, pressure and energy along the screw lamella positions 𝑆𝐿𝑝 of the screw press FL 200 by applying the tangent curve mathematical model and the screwline geometry parameters (screw shaft diameter, screw inner and outer diameters, screw pitch diameter and the screw thickness). The fitting curve value 𝐹𝑣 of the tangent mathematical model was further examined at 𝐹𝑣 = 2 and 𝐹𝑣 = 3 by identifying the force, deformation, stress and compression coefficients at varying vessel diameters 𝐷𝑣 and initial pressing heights 𝐻𝑡 of the bulk oil palm kernels. Based on the results of the stepwise regression analysis, the amounts of the theoretical deformation energy 𝑇𝐷𝐸 in linear pressing as well as the theoretical force 𝐹𝑟, pressure 𝑃𝑟 and energy 𝑆𝐿𝐸 of the screw press FL 200 were statistically significant (P-value < 0.05) or (F-value > significance F) in relation to the predictors (𝐻𝑡, 𝐷𝑣, 𝐹𝑣 and 𝑆𝐿𝑝). The coefficient of determination (R2) values between 61 and 86 % were observed for the determined regression models indicating that the responses 𝑇𝐷𝐸, 𝐹𝑟, 𝑃𝑟 and 𝑆𝐿𝐸 can accurately be predicted by the corresponding predictors. The normal probability plots of the responses approximately showed a normal distribution.