AEDC's oil cleaning program saves money, benefits environment

  • Published
  • By Philip Lorenz III
  • AEDC/PA
ARNOLD AIR FORCE BASE, Tenn. --  Energy efficiency and petroleum are currently hot topics in the news and no one has to look far to realize their importance, especially at a place like Arnold Engineering Development Center (AEDC).

Before initiating an oil cleaning program in 2005, AEDC's leadership and work force had already established and carried out best industry practices regarding the use of petroleum products, according to David Hurst, manager of ATA's reliability engineering branch.

"By keeping the oil in our hydraulic reservoirs clean, we improve the reliability and performance of the servo controllers used for control of the process air valves in AEDC's test facilities," he said. "With the improved performance of the control valves, we reduce lost test time, improve data quality and reduce the amount of time required to reach and acquire the test data. Because of the improved reliability, fewer servos need to be replaced, therefore, reducing maintenance costs. All of these factors reduce test costs and save energy for our test customers and for AEDC."

Hurst said being proactive has been one of the hallmarks of Arnold's approach to improving operational efficiencies and reducing costs.

"By testing the incoming oil as it arrives at AEDC, we potentially prevent the contamination of our hydraulic systems," he said. "For example, if we put one 55-gallon drum of dirty hydraulic oil into one of our larger systems, we could contaminate 5,000 gallons of oil which will have to be cleaned or disposed of.

"The cost of a drum of oil is about $500. If we had to replace the oil in the system, it would be about $50,000 for the material and labor to drain, clean and refill the system. The process to clean the oil in a large 5,000-gallon system would take five days during which we would not have access to the equipment that used this hydraulic system. The oil processing facility easily pays for itself each year in reducing lost test time and improving our performance and reliability."

Casey Schewe has been the system engineer for the Oil Processing Facility at AEDC for four years.

"We process both new and used oil for water and particulate contamination," he said.
"We have processed on average more than 4,000 gallons - greater than 75 drums - of used oil per year. Once the oil is cleaned, it is either stored for future use or returned to service in the facility which supplied it for processing."
Keeping up with inspecting and maintaining a clean supply of oil at AEDC keeps everyone involved with the process challenged and busy.

"The most destructive oil contaminant is water, and it also happens to be one of the toughest to remove," Schewe explained. "The oil processors we use at AEDC work by vacuum dehydration. The principle is the same as the reason water boils at a lower temperature in Denver than it does here in Tennessee - the lower air pressure.

"The oil processors reduce the air pressure around the oil so the water will come close to boiling at 140 degrees Fahrenheit. It would be like boiling water on top of Mount Everest. Since we don't get the oil really hot to remove the water, the chemistry of the oil doesn't break down and we can extend its useful life. While all of this is going on, we are also removing particles smaller than the diameter of a human hair. As a result the oil and the equipment will last longer and perform better."

In addition to the Oil Processing Facility, Schewe said there are several other oil processing operations currently in use near that site.

"A stationary unit is in use at VKF Plant, building 651, which is hard-lined into most of their major equipment," he said. "It is run by Otis Eady, an outside machinist, and has been in operation under his care for more than 15 years."

Mobile purification units are also used on site for situations where system-wide decontamination is necessary or removal and transport of the oil from the system is impractical.

"Danny Patterson's shop at the Engine Test Facility [ETF] plant operates several mobile purification units which have been in use for more than 20 years now," Schewe said. "The oil processing facility also utilizes a pair of mobile units for areas outside of ETF when necessary.

"I would estimate that these processes decontaminate more than 5,000 gallons a year, in addition to the amount of oil processed by our facility. If filtration and dehydration cannot return the oil to a serviceable condition, it is then sent on to our counterparts in the environmental branch. There it is combined with mixed oils collected from minor maintenance actions across the base for recycling within the DoD system."