Effect of design parameters on palm oil yield, volumetric flow rate and extraction efficiency of digester –screw press

Abstract

The study investigated the effect of design parameters (screw operational speed, screw flight and screw length) on palm oil yield, volumetric flow rate and extraction efficiency of digester-screw press. The results showed that increase in operational speed (from 10 to 20 rpm), screw flight (from 0.05 to 0.07 m) and screw length (from 3.5 to 4.5 worms) decreased palm oil yield (from 0.24 to 0.16), increased volumetric flow rate (from 4.3 x 10^-6 to 6.9 x 10^-6 m³s^-1) and decreased extraction efficiency (from 92 to 60%). Statistical analyses indicate that the separate effects of screw length, screw flight and operational speed are significant on palm oil yield, volumetric flow rate and extraction efficiency. All the interactive effects of these design parameters (except for screw length versus screw flight) on the performance parameters are not significant. The results of this study have implication in improving the machine’s efficiency as it will guide in the choice of appropriate combination of these parameters to achieve higher efficiency.