When TEG dehydration performance declines and the regenerator shows deposits or unstable operation, investigate salts, hydrocarbons, corrosion products, glycol degradation, filtration, reboiler conditions, and regenerator packing before changing the gas-contactor internals.

When amine-system performance declines because heat-stable salts accumulate, more regenerator packing or higher reboiler duty may not solve the problem. Analyze solvent composition, degradation, corrosion, fouling, reclaiming needs, and actual regenerator hydraulics separately before changing tower internals.

When an HCl pickling scrubber loses removal efficiency while pressure drop remains normal, inspect for oil-mist contamination and hydrophobic films. Oil can reduce aqueous wetting, spread through the recirculation loop, and lower effective packing area without causing severe blockage.

Marine exhaust scrubber design must consider soot, ash, oily particulate, seawater salts, evaporation, ship motion, wash-water solids, and allowable engine backpressure. Fine random packing can provide strong contact but may become an unintended soot-and-salt filter unless the solids duty is carefully controlled.

For seawater packed scrubbers, long-term reliability should include biofouling as well as alkalinity and chloride corrosion. Low-flow zones, stagnant operation, distributor branches, packing surface area, trapped solids, cleaning access, and water-treatment strategy can determine whether the tower maintains its original hydraulic capacity.