Abstract
•Wetted-wire columns are a promising alternative to packed and spray columns.•Densely-packed wetted-wire model indicates superior performance (low pressure drop)•The minimum pitch (center-to-center) between wetted-wires is on the order of 1–2 mm.•A bead passing phenomenon allows wires to be closer than expected.•Bead passing likely occurs because of air effects and not surface tension effects.
Arrays of vertical parallel wires (‘wetted wires’) are a promising alternative to industrial columns such as spray, tray, or packed columns. Yet, further research is required to optimize their performance and competitiveness against packed columns. This work investigates the maximum wire density using the minimum pitch (center-to-center wire distance). Results show that the pitch can be smaller than two millimeters, which is significantly less than the minimum pitches recommended in the literature. Results are discussed for liquid flow rates, wire diameters, and counter-current gas velocities. The minimum pitch is often less than the diameter of the drops due to a bead-passing phenomenon. An analytical model illustrates the pressure drop characteristics of wetted-wire columns compared to existing packings. This model shows that wetted-wire columns including those with small pitches have very low pressure drops. However, this model also shows that packing factors do not adequately describe wetted-wire columns. This implies that gas-side fluid dynamics of wetted-wire columns are fundamentally different from the gas-side fluid dynamics of packed columns.