Settling Behavior and CFD Simulation of a Gravity Separator

The design options of a gravity separator are still limited and rely on the study of settling behavior. A methodology will be presented where an experimentally given inlet droplet size distribution (DSD) is the basis for the calculation of the dispersion layer in a gravity separator. A pilot-scale continuous gravity separator is presented and CFD (computational fluid dynamic) results are validated. A transmitted light measurement technique for the determination of the DSD is presented up to a holdup of 15% dispersed phase. The resulting DSD was in the range of 20–2000 µm depending on flow rate and phase ratio. Furthermore, correlations of the real DSD with the settling behavior of the dispersion in a settling cell are discussed. The new approach to the description of gravity separators will be presented and the applied CFD methods showed good results with the system water/paraffin.