Velocities in moving granular bed filters

This paper concerns the velocity fields of three symmetric louver-walled mo ving-bed systems. The louver angles were 10 degrees, 20 degrees and 50 degr ees in the three experimental tests. The particle-tracking method and image -processing technology were employed to measure the granule velocity fields in the louver sections. The horizontal and vertical velocity distributions extracted from the velocity fields at five levels of the louver section we re plotted and discussed. The velocity profiles of filter granules are infl uenced by the louver geometry. In the steeper louver-angle system, the velo city profile of filter granules is similar to plug flow. The stagnant zones exist along the louver walls in the filter system with shallow louver sect ions. (C) 2001 Elsevier Science S.A. All rights reserved.