For fertilizer or phosphoric-acid scrubbers handling fluoride species and phosphate-containing solids, evaluate gas chemistry, particulate load, wet deposit behavior, packing openness, distributor blockage, solids removal, demister fouling, and complete material compatibility. A chemically resistant packing can still fail hydraulically if reaction or process solids accumulate throughout the liquid loop.

Plastic packing and fabricated polymer internals can be chemically suitable for a scrubber while becoming more vulnerable to impact during very cold shutdown, storage, installation, or startup. Minimum design temperature, resin grade, handling method, thermal transition, support restraint, and fracture evidence should be reviewed separately from normal corrosion resistance.

When a saline scrubber evaporates significant water, dissolved salts can concentrate until crystals appear on packing, distributor outlets, demisters, and tower walls. Level control alone does not control salt inventory. Blowdown, conductivity, evaporation, shutdown drying, packing openness, and separator washability should be managed together.

When hot moisture-rich gas is cooled in a packed scrubber, water vapor can condense inside the bed, increasing downward liquid flow while reducing gas volume. The design should evaluate the changing hydraulic profile, lower-bed liquid load, support drainage, dilution of scrubbing chemistry, sump balance, and demister duty rather than using only external circulation flow.

When an oxidizing H₂S scrubber forms elemental sulfur, the project must manage the resulting solids as deliberately as the original gas contaminant. Packing openness, distributor opening size, sump solids removal, oxidation control, demister washing, deposit analysis, cleaning method, and pressure-drop monitoring determine whether strong initial H₂S removal can be sustained long term.