
 Riser 
 Height (H), Kunii and Levenspiel [30] 
 
 Decay constant, Kunii and Levenspiel [31] 
 
 Choking voidage, Yang [32] 
 
 Solids circulation flux, Yang [32] 
 
 Terminal velocity of particles, Basu [2] 
 
 where and are given by, Basu [2] 
 
 
 
 
 
 Superficial gas velocity, Perales et al. [33] 
 
 Axial voidage fraction, Davidson [5] 
 
 Internal solids reflux, Davidson [5] 
 
 Solids inventory, Behainne and Martins [34] 
 
 
 Pressure drop, Behainne and Martins [34] 
 

 Cyclone 
 Swift geometrical configuration, Basu [2] 
 ; 
 
 Pressure drop, Muschelknautz and Greif [35] 
 
 Wall friction coefficient, Basu [2] 
 
 Tangential gas velocity, Muschelknautz and Greif [35] 
 
 Gas exit tube radius, Muschelknautz and Greif [35] 
 
 Parameters of cyclone design, Muschelknautz and Greif [35]

 
 
 Velocity at exit 
 

 Standpipe/solids recycle valve 
 Height above the aeration point, Knowlton [36] 
 
 Pressure drop in the vertical leg of the Lvalve, Knowlton [36] 
 
 Pressure drop in the Lvalve, Geldart and Jones [37] 
 
 Pressure drop in the riser above the solids return level, 
 Behainne and Martins [34] 
 
 Aeration mass flow rate, Geldart and Jones [37] 
 
 Solids inventory, Behainne and Martins [34] 
 
