This study presented computational fluid dynamics (CFD) and experimental validation
of hydrodynamic behavior of helical rings random packing. Random packings have been
widely used in chemical industries in absorbers, strippers etc. Up till now, development
of novel random packing structure has essentially been empirical. Even with the
increased computing power, CFD simulations of random packings are hard to find in the
literature. The random nature of the packing structures, and the stacked geometry make
acceptable grid generation and convergence very difficult because the structure of random
packing is complicated when large amounts of it are stacked in a column. In this work,
a CFD model was first time developed to simulate countercurrent gas-liquid flow in
random packings formed by helical rings. Gravity simulation was used to generate
stacking structures. A simple feedback control scheme was applied to control the gas
inlet flow rate so that a particular pressure. Multiphase model was employed to compute
the gas and liquid interaction in which the surface tension and wall contact angle were
found as key factors. The predictions of the CFD model were validated with a lab-scale
packed-bed absorber. It was found that the helical structure did increase the interfacial
area, liquid hold-up when compared to Raschig rings, and such predictions can be
validated by our in-house experiment. The model also showed that helical rings will have
lower pressure drop and can sustain a larger liquid-gas ratios compared to Raschig rings
. In summary, our study found that CFD simulations can obtain reasonable predictions
of hydrodynamic behaviour of packings, and the inclusion of microstructures into a
packing element will improve its hydrodynamic properties. These results showed that
CFD can be used as a basis for rational packing design.