Brine Pumps
Aircraft Carrier Brine Pump Problems:
A major problem facing the US Navy is that of brine pump failure on the ships. Due to this continuous problem one of the biggest shipbuilders in the US, Northrop Grumman decided to conduct a test utilizing the Eddy Pump technology in replacement of the existing brine technology. Tests showed that the existing distilling unit brine pump on CVN 68 class ships had high failure rates due mainly to premature motor bearing failure. This was in turn attributed to pump cavitations and related vibration with excessive packing gland leadoff. Based on the current brine pump’s operation at very close to the minimum required net positive suction head (NPSH), which subjects the centrifugal pump to severe cavitations, the need for a solution was of utmost importance. There was initial concern that the Eddy Pump would have difficulty working in vacuum application due to low NPSH, but due to the Eddy Pump principle of operation, which does not depend on NPSH this wasn’t a factor. Initially Eddy Pump was scheduled for a 3-6 month evaluation on the USS John F. Kennedy (CV-67) utilizing a horizontally oriented pump system with an 8-inch intake and 6-inch discharge. Due to the ship’s scheduling commitments the pump remained on for over one year and accumulated over 3,000 hours of runtime without any problem or failure. As of date the Eddy Pumps have been on the USS Kearsarge for over 8 years with no problems. Final analysis done by Newport News showed an average life cycle savings of $3,000,000 per ship by utilizing the Eddy Pump technology versus the existing brine pumps.
