Liquid flow on a vertical wire in a countercurrent gas flow

The concept of the wire bundle packing is regarded as a potential alternative to common structured packings in the chemical industry, but until now it is still in prototype stadium and its capability has to be proven. The packing mainly consists of parallel vertical wires that are supplied with liquid separately from a special liquid distributor. To gain insight into the fluid dynamics of the gas/liquid flow, experiments with a single wire in a channel are conducted. Different methods are employed to measure local film thicknesses, liquid hold-up, liquid bead velocities, load limits and pressure drop. Due to the strongly curved surface of the wire, the film flow differs from the fluid dynamics of liquid films on plane surfaces. The film flow shows a distinctive pattern of liquid “beads” that run on a thin basis film. When the film is subject to a significant counter current gas flow the flow pattern changes, but the liquid hold-up and the interfacial area are hardly influenced. This behaviour can be observed up to the load limit where the beads disintegrate and flooding occurs. An estimation of the fluid dynamic performance of the wire packing from the single wire experimental data is made. The results indicate that the interfacial area of the fully wetted packing exceeds the dry packing area up to 60%. The estimated pressure drop is about one magnitude lower than that of a comparable corrugated sheet structured packing and the load limits are significantly higher.