Performance evaluation of screw-press oil expeller using a continuous spiral and decreasing length of pitch of screw

Abstract

Mechanical designing of screw-press for obtaining optimum flow and pressure will be very costly affair. The flow velocity and pressure was predicted using an analytical solution of an isothermal Newtonian flow in finite screw channel. An innovative design of continuous spiral screw was developed for screw-press oil expeller. The flow velocities in the down channel range from 125 to 175 mm s^-1 through the length of screw from 150 to 500 mm for the screw drive of 48 rpm. The maximum pressure was built at the end of screw in the range of 9 - 10.57 x 10⁵ Pa. The theoretical pressure was close to the pressure measured during experiments for mustard and sunflower oilseed expelling. The lower screw speed resulted low heat generation and higher oil recovery.