2017 Volume 57 Issue 11 Pages 1902-1910
In this study, cold model experiments on particle blowing were carried out to clarify the effect of particle penetration depth on solid/liquid mass transfer rate. A comparison of penetration depth obtained by experiment and CFD calculation using commercially available software was also carried out. The penetration depth was measured by a visual observation whereas the solid/liquid mass transfer rate was obtained from the ion-exchanged reaction between Na+ on pearlite particles and H+ in HCl aqueous solution. Both of the penetration depth and solid/liquid mass transfer rate increased with the increase in particle feed rate and top blowing gas flow rate, and the decrease in lance height and particle diameter. The following non-dimensional equation of particle penetration depth was obtained by several non-dimensional numbers:
where, ReP: particle Reynolds number, Fr: Froude number, We: Weber number, ρl and ρp: liquid and particle densities (kg/m3), respectively. A good agreement was confirmed by the experiment. The particle penetration depth was also calculated by a combination of VOF and DEM model and it was in good agreement with the experiment. The solid/liquid mass transfer coefficient calculated by the CFD simulation and Froessling equation increased with the increase in top blowing gas flow rate, particle feed rate and penetration depth. The solid/liquid interfacial area was expressed by a function of penetration depth.