Elutriation of Fine Particles from a Vortexing Fluidized Bed
A systematic investigation of elutriation of particles is reported in the cold model of bubbling fluidized bed (BFB) and vortexing fluidized bed (VFB) of 0.19 m diameter and 4.0 m height. Glass beads were used as the fluidized material. The diameter of the coarse particles was 545 <I>μ</I>m, the diameter of the fine particles used for the elutriation test ranged from 49 to 194 <I>μ</I>m. The results indicate that the specific elutriation rate constant (<I>K</I><SUB>∞</SUB>*) is a function of the initial concentration of elutriated fine particles. The minimum value of <I>K</I><SUB>∞</SUB>* is obtained when the initial concentration of elutriated fine particles is reached 16 wt% in a BFB system. Based on the experimental data obtained from the BFB, a correlation is presented to estimate the <I>K</I><SUB>∞</SUB>*. The <I>K</I><SUB>∞</SUB>* is found to be a function of the particle terminal velocity, gas density, and modified Froude number (<I>Fr</I>*). For a wide particle size distribution (PSD) system, a new parameter, called particle size distribution factor, <I>γ</I>, is introduced to describe the specific elutriation rate constant of wide PSD elutriated fine particles. A method to estimate the specific elutriation rate constant of a multi-component system by using the specific elutriation rate constant of each component obtained from a binary particle mixture system is also presented in this study.
- Journal of chemical engineering of Japan
Journal of chemical engineering of Japan 31(6), pp.950-959, 1998-12-01
The Society of Chemical Engineers, Japan