MHPS Wet FGD

Gypsum scaling in the absorber comes from slurry density running too high or oxidation air being insufficient. Reduce slurry density to the design band and verify oxidation air flow before attempting mechanical cleaning.

SO2 removal falling short of the permit target is usually a slurry pH problem from poor limestone quality or a blocked spray level. Check limestone reactivity and slurry pH first.

Rising differential pressure across the mist eliminator means gypsum scale is blocking the chevron blades. Verify that wash nozzles are firing on schedule and not plugged. Plan a high-pressure water wash during the next outage.