Mist eliminators in annular or obstructed vessels must be sized from the true open cross section rather than full vessel diameter. Central pipes, supports, eccentricity, inner-edge bypass, drainage, segmentation, and thermal expansion all affect the final hydraulic performance.

High-altitude atmospheric scrubbers can have lower gas density and higher actual volumetric flow for the same mass or normalized gas rate. Mist eliminator face velocity, pressure drop, and capacity should therefore be calculated using actual site pressure and temperature.

Spray towers generate mist directly through nozzle atomization, while packed towers create entrainment through gas-liquid interaction, distributor behavior, and potentially flooding. These different mechanisms affect droplet size, liquid load, upset behavior, and mist eliminator selection.

Liquid carryover can wet activated carbon and molecular sieve beds, block pore access, carry salts or oils into the media, increase pressure drop, and shorten adsorption or drying cycles. Upstream bulk and fine mist separation should therefore be matched to the downstream media tolerance.

Quench towers create mist through spray atomization, rapid cooling, condensation, and turbulent gas-liquid interaction. Their mist eliminators must handle high liquid load, possible solids, temperature transients, uneven gas distribution, and strong drainage requirements.