Numerical simulation of flow patterns of disks in the symmetric moving granular filter bed

By extending the stack disk theory in the asymmetrical hopper by Chou et al.(1), the initial coordinates of the disks' center and the boundary of the filter are defined. By making use of the DEM model of Cundall & Strack(2), the now pattern histories of disks and the development of quasi-stagnant zones close to the louvered walls of the 2-D symmetrical moving granular filter bed were studied numerically. Three kinds of symmetrical moving granular filter bed ((i)>LA=30 degrees, RA=30 degrees; (ii) LA=40 degrees, RA=40 degrees; (iii) LA=50 degrees, RA=50 degrees) were used, respectively. LA is the angle between the left louver and vertical line, and RA is the angle between the right louver and vertical line. On the other hand, the flow pattern of disks in the 2-D Dorfan Impinge filter bed(3) (& 10) was studied numerically, too. The results of computer simulations of the louvered walls granular filter bed show that the angle of the louver affects the flow behavior of the disks, and are compared with those of Dorfan Impinge filter bed. The numerical results reported here and the experimental results by Kuo el al.(4) provide fundamental and important information for designing moving granular bed high-temperature flue gas cleanup filters.