SEGREGATION OF SOLID PARTICLES OF 2 SIZES IN BUBBLE-COLUMNS

Binary mixtures of solid particles were fluidized by a two-phase flow of gas and liquid. The changes in holdup of the two components with axial position in the column were determined. The experiments were conducted with three combinations of sieved glass beads (118 and 243 mu-m; 118 and 465-mu-m; and 243 and 465-mu-m diameter) in vertical columns of 7 cm diameter X 4.85 m height and 15 cm diameter X 2.7 m height under batch operation with respect to the solid phase. A sedimentation-dispersion model developed on the basis of the experiments gives a semi-empirical description of the axial distributions of segregation and solid holdup over the whole range of the column.