Deaerator Case Studies
CHICAGO HEATER REPLACEMENT VENT
Problem: The deaerator had water out the vent.
CHLORIDE ATTACK TRAY ENCLOSURE
Problem: The tray enclosure was ineffective due to chloride attacks on the deaerator.
Problem: Corrosion pits were observed in the deaerator storage section.
Problem: A deaerator was thinning out due to erosion underneath the tray stack.
DOG LEG VENT PIPE FAILURE
Problem: Many manufacturers provide a dog leg type vent with a miter joint which typically fails due to inadequate welding where the vent pipe supports the valve plate.
FLOW ACCELERATED CORROSION (FAC)
Problem: Vessel had severely high corrosion due to FAC.
HEATER STEAM EROSION
Problem: Various locations of the deaerator and heating section can be eroded by steam due to inadequate downcomer sizing, inadequate baffling and inadequate water distribution.
HIGH OXYGEN LEVELS
Problem: The customer complained about poor dissolved oxygen readings.
Problem: The deaerator scrubber was inadequately sized and destructed due to high velocities.
SPRAY DEAERATOR CORROSION
Problem: The deaerator is open to oxygen degradation due to non containment of the oxygen in the vessel.
SPRAY DEAERATOR WATER BYPASS
Problem: Water is bypassed in this spray deaerator due to high flow rates and/or inadequate sizing of tray pans
STRESS CRACK IN VESSEL SHELL
Problem: Cracking in deaerators is most often attributed to corrosion fatigue, where a crack results from a cyclic stress in a corrosive environment.
TRAY BOX SUPPORT PITTING
Problem: Pitting was noticed on the supports of tray box.
TRAY ENCLOSURE SUPPORT WEAR
Problem: The tray enclosure supports were ruined due to relatively high steam velocities and water erosion.
Problem: Tray holdowns on older units rely on sheer force to the tray box to compress the trays and hold the trays down.
Problem: Tray upsets are common in the deaerator industry if proper tray hold-downs and baffling are not provided.
WATERBOX SPRAY PATTERNS
Problem: Spray valves were improperly located over the trays allowing for water carry over to the vent
WELD OVERLAY ON DEAERATOR
Problem: Excessive pitting and/or erosion due to high velocity of steam and the deaerator will not perform properly.