Deaerator Troubleshooting – Kansas City Deaerator

Deaerator Troubleshooting

Symptom

High O²

Possible Causes

  • Air in-leakage
  • Insufficient stabilization period
  • Trays not installed properly and in place
  • Not steady state conditions
  • O2 inlet not in accordance with specified designed conditions
  • Spray valves not installed correctly
  • Water inlet temperature too low
  • Improper venting
  • Incorrect testing
  • Operation outside of design conditions

Comments or Possible Solutions

  • Loose fittings
  • Shut scavenger off
  • Remove chemical interferences
  • Verify design conditions

Symptom

Excessive Pressure Fluctuation

Possible Causes
  • Steam PRV improperly sized or calibrated
  • Improperly sized downcomer and equalizer
  • Inlet steam pressure too high or too low
  • Excessive inlet temperature variation
  • Heater flooding
Comments or Possible Solutions
  • Check size and calibration
  • Keep within design range
  • Check all valve and control settings
Symptom

Low Outlet Temperature

Possible Causes
  • Incorrect Thermometer reading
  • Insufficient steam flow
  • Incorrect steam/water ratio
  • Spray valves or internals malfunctioning
  • Heater flooding
  • Inlet flow piped incorrectly
Comments or Possible Solutions
  • Check calibration
  • Check steam supply
  • Check for restrictions
  • Check Pipe and valve sizing
  • Check heat and mass balances
  • Check spray valves, trays, etc.
  • Check all valve and control settings
  • Check all inlet flows and temperatures
Symptom

Water Hammer

Possible Causes
  • Inlet flows mixing just prior to Deaerator inlet
  • Improper pipe design
  • High inlet velocities
Comments or Possible Solutions
  • Mix flows farther upstream of Deaerator
  • Check and/or redesign
  • Keep within HEI
Symptom

High CO2

Possible Causes
  • High CO2 at inlet
  • High pH
  • Improper venting
Comments or Possible Solutions
  • Verify CO2 design condition
  • Lower pH
  • Review vent system
Symptom

Tray Upsets

Possible Causes
  • Tray hold down not secure
  • Turbine trip
  • Flashing
Comments or Possible Solutions
  • Install correctly
  • Gradual increase/decrease of controlled flows
Symptom

Unexpected Storage Tank Level Excursions

Possible Causes
  • Malfunctioning level control system
  • Malfunctioning overflow or improper boiler feed pump operation
  • Pressure fluctuations
Comments or Possible Solutions
  • Check setting and system operation
  • Check overflow level and boiler feed pump operation
  • See pressure fluctuations above
Symptom

Water Out of Vent

Possible Causes
  • Cracked vent welds
  • Improper vent piping
  • Water carryover
Comments or Possible Solutions
  • Repair or redesign
  • Should be as short and as vertical as possible
  • Reset vent flow
Symptom

Iron Oxide in Deaerator

Possible Causes
  • Condensate or system corrosion
  • Frequent shutdowns
  • High O2
Comments or Possible Solutions
  • Keep positive pressure on Deaerator
  • See High O2 section above