How to diagnose ammonia injection malfunction on a Babcock and Wilcox B&W SCR
Zero or erratic AIG flow almost always means a stuck control valve, plugged nozzle, or cold vaporizer. Verify vaporizer temperature, check valve positioner output, and inspect the injection grid nozzles.
~90 min7 steps
How to diagnose catalyst deactivation and declining NOx efficiency on a Babcock and Wilcox B&W SCR
Gradual NOx efficiency loss that requires increasing ammonia to compensate is a sign of catalyst deactivation. Pull a catalyst sample for activity testing and check for arsenic or alkali poisoning.
~120 min7 steps
How to clear catalyst plugging and high backpressure on a Babcock and Wilcox B&W SCR
Rising backpressure on an SCR catalyst bed is almost always ash or soot accumulation. Trigger soot-blowing, inspect inlet baffles, and schedule a catalyst wash if the differential pressure stays high.
~60 min7 steps