December 19, 2003

By: Dustin Cyril
Website: http://www.water-purification-filters.com

Hydraulics -- A fluid revolution

From tractors to tow motors to torpedo lifts, hydraulics keep the U.S. Navy on the move. They also keep Navy environmental officials on their toes, looking for new ways to reduce the consumption and disposal of hydraulic fluids, which pose a significant hazardous waste challenge.

In just the past two years, Navy pollution prevention (P2) initiatives, under the direction of the Navy Environmental Leadership Program (NELP), have made tremendous progress.

Maintenance of hydraulic fluid has always been fairly straightforward. Hydraulic systems are highly sensitive to fluid impurities, so the fluids must be checked frequently for signs of contamination. Metallic particles are the contaminant of primary concern, but water and chlorinated solvents can do damage as well. When contamination exceeds the applicable Navy standards, the fluid must be removed and disposed of. But what if the contamination could somehow be extracted from the fluid and the fluid’s life-cycle extended? The resulting reduction in fluid consumption and disposal could yield significant benefits both to the environment and to the Navy’s bottom line.

Such a notion seemed far-fetched just a few years ago, when the Navy first began looking into purification technologies. In 1995-96, NELP successfully prototyped two types of purifiers at its East and West Coast home bases, focusing on ground service equipment (GSE) used in AIMD activities. The purifiers use sophisticated filtering systems to remove contaminants without desiccants or high heat, which tend to alter the physical or chemical properties of the fluid. These small, portable, electrically powered devices can in many cases be connected directly to the GSE’s fluid reservoir, eliminating the need for purging and refilling the system.

In addition to the environmental benefits, the NELP demonstration showed considerable cost savings by reducing waste disposal volumes, new fluid purchases, and labor hours for fluid maintenance. Factoring in an initial procurement of $8,479, the prototype broke even in less than 2 years and promised a return on investment of $36,500 over 10 years.

As a complement to the fluid purifiers, technologies to improve contaminant measurement proceeded along another track. In the past, the only way to measure particulate contamination was with the "patch" test, in which a sample of used fluid is extracted, "cut" with the solvent PD-680, and examined for particle content. Not only did this test add a hazardous solvent to the waste stream, but it was time-consuming, inexact, and required a subjective interpretation.

Enter the electronic particle counter. These portable devices provide quick, precise measurements that allow for more objective decision-making. If the count exceeds the applicable standard, the fluid must be either be disposed of or reconditioned using the hydraulic fluid purifier.

A typical particle counter has three components: a digital counter with printer, an automatic bottle sampler, and a liquid sensor incorporating laser diode technology. As with the purifiers, particle counters were tested on GSE at both NAS North Island and NS Mayport. The tests found that each system performed satisfactorily and "may even be applicable to fluids other than hydraulic oils."

Like the purifiers, particle counters yield both environmental and cost savings. The cost analysis found that labor constitutes approximately 86 percent of the total cost of the most commonly performed "dry" patch test. One dry patch takes about an hour, but the particle counter was able to do the job in just 8.5 minutes. With an initial procurement of $7,500, and assuming 55 measurements per month, the demonstration broke even in just 14 months and returned a projected $57,000 on the investment over 10 years.

Although the final test report recommended only that particle counters be used as a supplement to the existing patch test method, subsequent process and equipment refinements have allowed the AIMDs to make a more complete transition. "The particle counter has been so effective that it is now used exclusively on support equipment at AIMD," according to Mayport P2 Director Bob Tierney.

Tierney adds that both fluid purifiers and particle counters are providing excellent service and that down the road, he sees their use being expanded into more and more areas across the base and Navy-wide. Already, he says, similar systems are already being prototyped on ships under the P2 Afloat initiative.

Author Notes:

Dustin Cyril contributes and publishes news editorial to http://www.water-purification-filters.com.  Get educated on the benefits of water purification systems and different water filters available.