Reduction of Extrusion Wall Friction in a Screw Press by Electroosmosis, Part 2

Abstract

This article describes the use of electroosmosis to reduce wall friction in a screw press. The aim was to reduce the water content within the pressed material and thereby save drying energy or decrease the power consumption of the press while maintaining the same extrusion rate. To investigate and quantify the effect of electroosmosis, a piston press with core die and an adjustable electrode mechanism was constructed. Clays from various brick manufacturers were used as testing materials. For all clays a reduction in extrusion force was observed, with plastic roof tile clays showing slightly better results than less plastic shale clays. Anode corrosion and high construction effort for huge presses are problems for practical deployment of this process.