In the oil expeller, kernel is continuously fed to the expeller which grinds, crushes,
and presses out the oil as it passes through the machine. The oil flows through the
perforated casing and is collected underneath while the residue (oilcake) is pushed out
of the end of the unit (Fellows & Hampton, 2000). The extracted oil is classified as
crude PKO because it still contains some extraneous materials such as seed debris and
minor chemical constituents like gum, hence requiring clarification in a filter press or
by sedimentation.Settling and Clarification Tank
The crude PKO is pumped or flows by gravity to a sedimentation basin and is either
allowed to stand undisturbed for a few days and the upper layer is removed by the use
of clarifier (Fellows & Hampton, 2000). The settled foots is recycled to the press to
recover the entrained oil.