화학공학소재연구정보센터
Powder Technology, Vol.343, 342-349, 2019
Segregation of glass beads in three-sectional tapered fluidized beds with ternary system
The objective of this study was to determine the effect of initial mixing ratio of glass beads and superficial gas velocity on mixing and segregation in a ternary system gas-solids three-sectional tapered fluidized bed with a cone angle of 25. The bed material was a ternary solid mixture consisting of three particles [ilmenite (d(p) = 153 mu m, rho(s) = 3860 kg/m(3)), coke (d(p) = 582 mu m, rho(s) = 1762 kg/m(3)), and glass beads (d(p) = 150 mu m, rho(s) = 2500 kg/m(3))] with different particle sizes and densities. Ternary solid mixture with glass beads at five different initial mass fractions (15%, 35%, 55%, 75%, and 90%) and a mass ratio of ilmenite to coke of 0.7:0.3 was tested. The three-sectional tapered fluidized bed used in this study comprised the following three sections: a cylindrical type reaction zone (ID = 0.14 m, H = 028 m) at the top of the distributor, a tapered zone (cone angle = 25 degrees, H = 0.17 m) at the top of the reaction zone, and a cylindrical type expanded zone (ID = 0.30 m, H = 1.55 m) at the top of the tapered zone. The bed composition was determined after taking a sample in the axial direction from the sampling port on the side of the bed. Vertical segregation occurred at a given gas velocity based on results of axial bed composition analysis. A comparison of the bed of the bottom reaction zone with that of the top expanded zone showed that segregation occurred with a maximum difference of 25 wt%. The separation efficiency of glass beads was increased with increasing initial mass fraction of glass beads. (C) 2018 Elsevier B.V. All rights reserved.