All kinds of damage can occur in a precipitator. These units are subjected to acidic ash, heat and outright fire. The ash ruins clothing, boots, eye glasses, wrist watches and gets in one’s eyes, nose and ears. Flyash is a know carcinogen. Sometimes a plant will send its worst crew to fix whatever they find and the supervisor will not venture inside.
The diagram at the left depicts structural distortion. A fire sufficient to cause that kind of damage will destroy the collector plates and the weakened frame will not be the first thing to catch an inspector’s eye. A bit more subtle is slight distortion of components, such as the anvil support shown at the center diagram. Because of it, the collector plates will be misaligned and can bow. The drawing at the right shows a collector plate separating. Ignore it and the plate will continue to deteriorate. This, too can be repaired in a way that restores full function. Just about any damage in a precipitator can be repaired during a routine maintenance outage and with the proper design, electrode clearances will not be impaired. That’s also the time to fine-tune electrode alignment. Many seriously damaged precipitators have been restored to higher efficiency than when first installed.