Numerical Calculations of the Breakup of Highly Loaded Slurry Jets

Abstract

A complete numerical calculation procedure for predicting the effects of mass loading and particle diameter on laminar slurry jet breakup in a low velocity, coaxial gas stream has been developed. The method is based on the Volume of Fluid technique for the Navier-Stokes equations. The severe restrictions involved in earlier treatments have been relaxed. The influence of particle loading on liquid phase density and the influence of particle spacing on drag are included. The particular case considered is a slurry with a methanol liquid phase with aluminum oxide beads in order to compare with some related experimental results. The methanol liquid in the slurry is vaporized due to mass transfer in the gas stream. The variation of the instantaneous jet shape of the methanol slurry jet at low loadings is generally similar to that of an all-liquid methanol jet, but the final shapes at breakup are different. In the region of low mass loading (up to 20 percent), the effects of mass loading are to stabilize the interface and increase the breakup time of the slurry jet with increasing mass loading. Above that region of mass loading (more than 20 percent), the effects of mass loading are to destabilize the interface and decrease the breakup time of the slurry jet with increased mass loading. At the same mass loading condition, a slurry jet with large diameter particles has a more stabilizing effect than one with small diameter particles. Therefore, a slurry jet with higher mass loading and smaller diameter particles breaks up faster.