HYDRODYNAMIC CHARACTERISTICS OF LIQUID-SOLID FLUIDIZATION OF BINARY MIXTURES IN TAPERED BEDS

The problems associated with fluidization in cylindrical beds like entrainment of particles, limitation of operating velocity could be overcome by adopting tapered beds. There have been no systematic studies reported on fluidization behavior of binary mixtures wherein the effect of size ratio is considered on the hydrodynamic characteristics of liquid-solid fluidization in tapered beds. In the present work, an attempt has been made to study the fluidization behavior and hydrodynamic characteristics of liquid-solid fluidization of binary mixtures of size ratios ranging from 1.2 to 5.13 using sand of different sizes in tapered beds of apex angles 5 0 , 10 0 and 15 0 . Water has been used as the fluidizing medium. Three types of fluidization behavior have been observed which may be classified into (1) mono component behavior, (2) partially segregated behavior and (3) completely segregated behavior. The fluidization process is discussed in detail. Correlations have been presented for hydrodynamic characteristics.