Category Archives: Heat Exchangers

Fouling of Main Engine Lube Oil Cooler

Fouling of main engine lube oil cooler may result in high lube oil temperature and low lube oil pressure. Lube oil coolers can be plate type or shell and tube type. However the reasons for poor cooler performance are:

  • Fouling of oil side, or
  • Fouling of cooling water side

As far as plate type coolers are concerned, cleaning is much easier. Shell side of lube oil coolers are normally designed with baffles and fins for enhanced heat exchange. Chemical cleaning is carried out regularly for the shell side. This removes sludge adhered inside and increases heat transfer efficiency.

Reasons for Poor Cooler Performance

  • Fouling of either lube oil side or cooling water side or both
  • Insufficient circulation of cooling water
  • Malfunctioning or improper adjustment of temperature controller / three way valve
  • Air lock inside the cooler
  • Choked cooling water inlet filter (for plate type coolers)
  • Broken or misplaced baffle plates (for shell and tube coolers)

How to Rectify

  • Keep the vents for cooler open, ensure vent is not choked and both lube oil and cooling water sides are free from air lock
  • Carry out chemical cleaning of cooling water side
  • Back flush the cooler
  • Check the cooling water pressure and quantity flowing through the cooler
  • Check¬†adjustment of temperature controller / position of three way valve
  • Clean inlet filter for cooling water
  • Ensure baffle plates are in position
  • If necessary, take out tube nest out of the cooler for cleaning sludge (for shell and tube coolers)
  • Clean cooler plates manually (for plate type coolers)