Wheat Purification of Straw Residues Using an Induction Type Electrostatic Separation

In this paper, the extraction of straw residues mixed with wheat grains using an electrostatic separator is studied. The used induction-based roll-type separator is mainly composed of an energized cylinder installed above a metallic grounded conveyor. The electric force created between induced charges on straw particles and the energized cylinder causes the attraction of straw residues. Therefore, applied high voltage and the distance between the cylinder and the conveyor are the main parameters that define the electric field intensity. The combined influence of the roll speed and voltage on the separation efficiency is evaluated using the experimental design methodology. The roll voltage and distance from the grounded conveyor are the factors for which the process is optimized. Experimental modeling results show an increase in separation efficiency when increasing applied voltage and decreasing distance. For optimal values, purity of over 98% is reached starting from an initial mixture of 71% purity.