When droplet size is unknown, mist eliminator selection can begin from the droplet-generation mechanism, liquid loading, fouling condition, gas flow, downstream sensitivity, and existing operating history. Unknown data should remain identified as uncertainty rather than replaced by an arbitrary assumed micron value.

Mist eliminator active area can be smaller than the vessel cross-sectional area because of supports, frames, structural obstructions, fouling, and uneven gas distribution. Using nominal vessel area alone can underestimate the true gas velocity through the separator.

Mist eliminator commissioning should verify installation, orientation, edge sealing, drainage, differential pressure, operating load, and downstream carryover. Recording a clean baseline under known process conditions provides essential data for future diagnosis and maintenance.

Fouling creates a persistent physical restriction, while hydraulic flooding is caused by temporary liquid holdup and often improves when gas or liquid load is reduced. Trend behavior and shutdown inspection help distinguish the two.

Salt-bearing droplets can crystallize inside a mist eliminator as water evaporates and concentration increases. Fine mesh can plug rapidly, so drainage, geometry, wash strategy, pressure-drop trends, and salt solubility should be considered together.