Physical and numerical characterisation of an agitated tubular reactor (ATR) for intensification of chemical processes

This study investigates the dynamics of a novel, oscillatory, intensified plug-flow reactor – an agitated tubular reactor (ATR) – designed for efficient flow processing of solid-liquid mixtures. The relative movement of the reactor and agitator bar, and associated effects on fluid mixing, were characterised physically with a suite of experimental instruments – utilising laser-based, video-based and acoustic techniques – and numerically via a Lattice Boltzmann method (LBM) computational fluid dynamic simulation. The reactor volume consisted of a cylindrical outer tube containing a free-moving, perforated agitator tube. The position, velocity and angular velocity of the inner agitator relative to the outer tube were measured experimentally and computationally under a range of realistic operating conditions, in terms of applied agitation frequency and displacement distance, along with their effect on the associated fluid velocity and turbulence levels. Additionally, simulations were used to validate a model for the reactor power input. The agreement between experimental and simulation data was very good in all cases, leading to clear recommendations for optimal operating conditions, while an experimentally derived regime map of the types and magnitudes of ATR motion is also presented.