Demister and Mist Eliminator Housing Lining

The challenge

The housing around a mist eliminator carries wet, aggressive vapor that sits against the wall above the liquid line, and over time that vapor thinned and pitted the steel where it pooled. The support ledge that the demister pad rests on had also lost metal, so the ledge no longer held the pad flat. When the ledge drops out of plane the pad stops sitting true, vapor finds a path around it, and the housing keeps losing wall in the same spots. Left alone, the thinning wall puts the integrity of the housing at risk and the pad cannot do its job.

Our approach

We take the housing internals back to clean steel by grit-blasting so the rebuild and the lining have a sound surface to grab. We rebuild the pitted wall and the worn pad support ledge with composite, returning the lost metal, then we dress the ledge back flat so the pad seats true on it. After the rebuild is shaped, we line the housing internals with a barrier coat matched to the vapor chemistry, putting the rebuilt areas and the surrounding wall under one continuous film. That way the demister seats correctly and the wall is separated from the vapor that was eating it.

1. Assess and confirm chemistryWe inspect the housing internals to map the pitting on the wall and the metal loss on the pad support ledge, and confirm the vapor chemistry so the lining is keyed correctly.
2. Grit-blast prepWe grit-blast the housing internals to clean, profiled steel so both the composite and the barrier coat bond to bare metal.
3. Rebuild wall and ledgeWe rebuild the pitted wall and the worn pad support ledge with composite, returning the lost metal back to profile.
4. Dress the ledge flatWe dress the rebuilt ledge back flat and in plane so the demister pad seats true on it.
5. Line and return to serviceWe line the internals with a barrier coat matched to the vapor chemistry, putting the rebuilt areas and the wall under one film, then hand the housing back ready for the pad to be reset.