DIRECT NUMERICAL SIMULATION STUDY ON THE FREE LIQUID AREA IN LIQUID-PARTICLE AGGLOMERATES.

Abstract

Multiphase flows often occur in intensified industrial processes and understanding these complex processes is instrumental in their design and optimisation. In gas-phase polymerisation reactors, the heat management is improved by injecting an inert liquid. However, the injected liquid also affects the collisional behaviour of the produced particles. The liquid can create agglomerates of particles due to cohesive forces, e.g. surface tension. The formation of these agglomerates can have a drastic effect on the efficiency of the process. To determine the lifetimes of the agglomerates, it is important to predict the evaporation rate of the liquid inside such an agglomerate. The evaporation rate of the liquid is dependent on the gas-liquid interface which can be studied using Direct Numerical Simulations (DNS), specifically a combination of a Volume of Fluid method and an Immersed Boundary method. The effect of contact angle and particle configuration on the interface area is studied in this work. This study showed that the random particle configuration has a large impact on the interface area. Due to its random nature, the six investigated configurations are not sufficient to provide a meaningful average area. To determine the interface area, more different random configurations need to be investigated in order to provide a conclusive answer.