Modeling of solid–gas flow fields via a correlation study

Abstract

A correlation study for modeling of solid–gas flow fields is presented with an emphasis to the extents of single phase gas flow through stationary vertical packed beds of solid particles and dilute phase flow of suspended solid particles in horizontal channels. The experimental data in terms of local static pressure gradients dP/dx in flow direction are processed. The referred test cases are (i) horizontal air flow with fully suspended fine solid particles of the size range 75.5μm≤dp≤275μm for the magnitudes of superficial air velocity; U»minimum fluidization velocity; Umf, (ii ) air flow through a vertical fixed packed bed of solid particles with dp=6000μm for U«Umf. The visual observations at U=Umf through the vertical beds of solid particles with dp range; 150μm≤dp≤2750μm are also referred.A non-dimensional mode parameter P* is defined using well-known permeability parameter Pf, mixture density ρm and a time parameter t* as an original contribution. The proposed relationships of P* with air flow Froude Number, Fr and solid particle Froude number Frs determine the limits of the flow fields. The magnitude of P* is 1150 for stationary packed solid particles with Fr≤2. Meanwhile P*≤2 corresponds to the dilute phase flow of solid particles in air for Frs≤60. The proposed equations can also be used for the determination of solids velocity Us, U and Umf in the cited limits of Frs, Fr with an acceptable error margin of <±24%.