Flow Regimes in Vertical Pneumatic Conveying

This paper presents a numerical study of the flow regimes in a vertical pipeline by a combined approach of discrete element model for solid phase and computational fluid dynamics model for gas phase. Two typical cases, i.e. the transports of glass beads when Solid Loading Ratio (SLR) = 0.5 similar to 3.4 and polyethylene pellets when SLR = 7.3-33.0 are considered. The results show that in both cases, the phase diagrams featured with the flow transition between the dense-phase flow and dilute-phase flow can be produced. In the transport of glass beads, only the dispersed flow regime is observed. However, both the slug flow regime and the dispersed flow regime are observed in the transport of polyethylene pellets. These results satisfactorily agree with the experiments.