Gas–liquid distribution in tubular reactors with solid foam packings

• Wire-mesh sensors are capable of visualizing liquid distribution in packings.
• Foam packings can develop liquid maldistribution along the flow path.
• A homogeneous initial liquid distribution across foam packings is essential.

The axial evolution of gas–liquid distribution patterns in co-current downward gas–liquid two-phase flow through solid foam packings of different pore density expressed by pores per inch was experimentally studied. The experimental results are based on time-averaged capacitance measurements of the liquid phase with embedded wire-mesh sensors, positioned at different axial heights of the solid foam packing. The measurements revealed the spatial distribution of the liquid phase saturation, which was applied to quantify the degree of liquid maldistribution. Both the spray nozzle and the multipoint distributor provide rather uniform initial liquid distributions across the foam packings with low maldistribution factors at superficial liquid velocities above 0.009 m/s. However, the uniform initial irrigation deteriorates along the foam packing length, in particular for foams with low pore density. The gas flow rate does not significantly influence the liquid distribution. Furthermore, the foam’s ability to radially spread the liquid phase in the cross-section downstream from a single drip point distributor was studied and found to be low, independent from the pore density.