An innovative wet scrubber system for micron and submicron particles removal from exhaust gas through a gas–liquid cross-flow array (GLCA) is proposed, which is formed by wastewater vertically falling down along a number of staggered wires. The smoothly flowing circular wastewater films on the outer surface of wires act as wet-wall columns to collect particles suspended in the exhaust gas flowing perpendicularly across it. An analytical model is developed to predict the particle removal performance of the GLCA, based on limiting trajectory analysis (LTA) of particle movement orientated by forces on a particle including diffusiophoresis (DP) and thermophoresis (TP). The LTA model, which combines particle motion equations and flowing gas velocity/temperature/humidity distributions in the boundary layer around a column, indicates that the particle grade removal efficiency (PGRE) for micron and submicron particles (0.1–10 µm) in the GLCA is dominated by different mechanisms according to particle size. DP has a more important effect causing the removal for the particle size range from 0.1–4 µm, while DP and inertia impaction dominate the removal process for the particle size range from 4–10 µm. The experiments on a lab-scale GLCA test rig equipped with Palas welas Digital 2000 were carried out with variable inlet gas temperatures and relative humidities, and a constant falling water temperature of 20°C. The PGRE measurements for the particles diameter size range between 0.1 and 10 µm compare satisfactorily with the model predictions.