Design and CFD Simulation of Knockout Drum

Abstract

Recently, the emission of black smoke over local area of Basra Oil Company from flaresystem represents a big problem facing the company and causing huge pollution in thesurrounding environment. The main reason of emission black smoke is carryover of droplets ofthe rest hydrocarbons such as condensate and droplets of crude oil by gases which are camefrom degassing stations facility in the north Rumelia field, southern Iraq. In this study, adesign methodology was developed for designing the knockout drum, and different designcriteria were used in sizing and selecting the drum based on the specification of the inlet fluidmixture. Three designs of knockout drums with respect to the gas conditions were performed.The horizontal knockout drum with a diameter of 2.5 m and length of 5.5 m was simulatedusing a Computational Fluid Dynamics (CFD) model (ANSYS FLUENT 15.0). The CFDmodel predicted very well the two-phase flow behavior and proved the need for a vortexbreaker at the liquid outlet. The CFD simulation revealed quantitatively that the designconfiguration of the knockout drum performed the separation of condensate droplets fromnatural gas with excellent efficiency.