Outlet moisture measurements can verify whether downstream carryover meets a requirement, but they cannot determine removal efficiency unless inlet liquid loading is also known. Sampling location, temperature, flow basis, condensation, and operating load must be controlled for meaningful comparison.

Mist eliminator pads can collapse or move because of high differential pressure, wet or fouled weight, liquid slugs, inadequate supports, missing hold-downs, corrosion, creep, or vibration. Failure analysis should examine the complete mechanical load path before replacement.

Mist eliminator performance can worsen after cleaning if mesh is deformed, segments are reassembled incorrectly, hold-down systems over-compress the pad, deposits remain internally, or cleaning residues alter wetting. Post-maintenance DP and carryover should be compared with the original clean baseline.

When direct mist eliminator liquid-loading data is unavailable, the duty can be screened from upstream droplet generation, separator spacing, drainage rate, operating history, spray conditions, and packed-bed behavior. Estimated and unknown inputs should remain clearly distinguished from measured data.

Boiling and evaporation generate entrained droplets through bubble bursting and vapor flow. Boil-up rate, liquid level, foaming, viscosity, surface tension, concentration, and disengagement space all influence the liquid load reaching the mist eliminator.