By Douglas J. Smith, IEng
VERO BEACH MUNICIPAL Power Plant supplies electric power to the city of Vero Beach, Florida. Although the city currently has sufficient electric supplies, the rapid growth of the Mid Coastal Florida area requires additional capacity. Besides considering the construction of new capacity, the utility has looked at ways to optimize their existing generating equipment. In 1997 the utility contracted with ISOPur Fluid Technologies to determine the benefits of utilizing a lubricating oil purification system to:
- Increase the reliability and service life of steam turbines
- Reduce operating and maintenance costs
- Limit forced outages
To help achieve these goals, Vero Beach is utilizing the ISOPur I-600 Series oil purification system. The system is designed for power generation equipment with flow-rates ranging from 600 to 1,000 g/hr and tank sizes up to 5,000 gallons.
According to ISOPur Fluid Technologies, the system’s patented technology, Balanced Charge Purification (BCP), allows power plants to reach a level of oil purity that conventional mechanical filtration cannot achieve. Besides cleaning the oil the system prevents the buildup of sticky particles in bearings and valves. It also removes varnish and sludge that cause bearing failures.
ISOPur’s BCP process uses a balanced electrical charge to separate contaminants in oils and fuels. In operation the system extracts small particles of dirt and contamination from inside the machinery. These contaminants, which end up in the oil, are then removed. Conventional oil filters on the other hand create a net static charge on oil particles, which causes the formation of sludge and varnish. The BCP technology restores a balanced charge to the oil, which induces the particles to stick together to create larger filterable particles. It also blocks the attraction of particles to internal surfaces and the formation of varnish.
Management personnel from Vero Beach Municipal Power Plant initially learned of the technology while attending an independent power plant maintenance conference. At the conference, Vero Beach personnel learned how engineers at a major pharmaceutical manufacturing plant had significantly extended the life of steam turbines by using the ISOPur system to purify the oil. The plant engineers reported that fluid purification reduced unscheduled maintenance and forced outages at the facility.
Vero Beach steam turbine Unit 1 lubricating system. Photograph courtesy of ISOPur Fluid Technologies.
In the past at the pharmaceutical plant, as part of a five-year scheduled outage for steam turbine maintenance, the oil would be replaced and the sludge and varnish buildup in the tank, lines and bearings removed by scraping. The oil change and cleanup typically took 10 to 14 days to complete. Since installing the BCP technology the pharmaceutical plant’s maintenance personnel are convinced that they will be able to extend steam turbine outages from five years to eight years or even longer.
“We were very impressed with the system’s ability to successfully extend the life of the steam turbines at the pharmaceutical plant and as a result we decided to install an ISOPur system on our three GE steam turbines in 1997,” said Peter Lindberg, Plant Manager, Vero Beach Municipal Power Plant.
Since installing the BCP system the life of the plant’s steam turbine bearings and shafts has been extended and the oil reservoirs are cleaner. Additionally, it has reduced the need for oil changes and oil disposal costs.
“At Vero Beach, we have not had to change the oil in our turbines since 1997. The savings in the cost of the lubricants and the disposal costs have helped us stretch precious operations and maintenance dollars,” said Mike Siefert, Director of Engineering, Vero Beach Municipal Power Plant.
The plant is now able to remove the varnish and sludge buildup and flush the lubricating oil system in one day. This work is done prior to a scheduled outage. According to Siefert, this is equivalent to a 2,000 percent reduction in maintenance downtime.
With the new system Vero Beach has been able to sharply reduce scheduled and unscheduled equipment downtime, maintenance and operating costs. This in turn has extended the service life, reliability and availability of the steam turbines.