CFD Simulation of Two Phase Separator “Slug Catcher” Type

Abstract

A two-phase mixture of gas and liquid enters a Gas treatment plant. This mixture is received by two Slug-Catchers, devices used to settle and separate liquid and gas phases. A Slug-Catcher is constituted by three large diameter tubes (also called “fingers”) that act as liquid accumulators, connected to each other by some inlet and outlet manifolds. During the pigging of the upstream ducts of the plant, slugs of liquid are produced and must be retained in the Slug-Catchers to avoid operational risks. The objective of this work was to evaluate through CFD the system's capacity to handle the liquid in a slug event. Additionally, to assess the capacity of the inlet manifold to symmetrically distribute the liquid in both slug-Catchers. The ANSYS suite was used to solve the problem, SpaceClaim to generate the geometry, Meshing to generate the mesh and Fluent R2020 for the simulation. The results are that no significant amount of liquid through the gas outlet in the Slug-Catchers, but rather a uniform and segregated filling, without flooding the system is observed. A uniform filling of the 3 finger was observed, distributing in the main fingers from the entrance and in the third finger through a communicating pipe. Therefore, it is concluded that the system can correctly handle the Slug.