Hygroscopic and deliquescent salts can absorb water from humid gas, turning dry deposits into sticky or liquid brine layers that increase pressure drop, reduce drainage, and trap additional solids. Seasonal humidity and temperature changes can therefore alter demister fouling behavior.

Oscillating mist eliminator DP often indicates dynamic liquid inventory, foaming, intermittent slugs, drainage cycling, or changing gas/liquid load rather than steady permanent fouling. Correlating DP with process signals can reveal the mechanism.

Dry DP testing can identify major geometry or fabrication problems but cannot verify wet liquid-handling capacity, flooding behavior, drainage, or re-entrainment. A clean wet operating baseline after commissioning is therefore essential.

Directional vane mist eliminators can underperform if installed backward because blade turns, hooks, and drainage pockets are designed for a specific gas-flow path. Flow arrows, module labels, installation drawings, and pre-startup inspection are essential.

Changing scrubber pH can alter salt solubility, precipitation, corrosion products, foaming, surface tension, and droplet behavior. These changes can increase demister fouling or carryover even when gas flow, liquid circulation, and separator geometry remain unchanged.