In expression operation using filter-press of compression type, slurry material is filtered by pressure provided by a pump. When the chamber is filled with filter cake, the cake is expressed by the movement of the flexible diaphragm. Exact identification of the time that the chamber is filled with the cake is essential for effective operation of the press. The electrokinetic response provides us with some information on the status of the filter chamber. In this work, we have measured the time course of electric potential difference (EPD) between the retaining walls during the whole process of expression to elucidate the electrokinetic aspects of mechanical dewatering. The experimental apparatus used in this study consists essentially of a piston press with a cylinder and a piston of 6 cm or 10 cm in diameter. Filter media are placed at the cylinder bottom and the very end of the piston. EPD between the filter media was monitored during the experiment. The absolute value of EPD increases with the progress of the filtration period, followed by the decrease during the consolidation period. It was observed that...
Session: L2 - Particle, Slurry and Cake Characterization
Day: 22 October 2019
Time: 14:45 - 16:00 h