Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/778560
The first test for TXP on the second unit occurred in December 2014, approximately eight months after the flush. The TXP levels came in at 2.2 percent. The next test for TXP took place in October 2015. The TXP levels were now 1.87 percent. The question was whether the levels were actually decreasing or were the results within the percentage of devia- tion for the test. After the second unit's flush and TXP testing, preparations were made for the first unit. Its TXP levels at 24 hours of circu- lation were 1.2 percent. At three months, the levels increased to 1.9 percent, and at six months, they rose to 2.11 percent. The tests correlated with a darkening of the fluid as well as an increase in the blotter test rings, the MPC color and the weight of the patches. Although the particle counts were within the specified range, only particles greater than 4 microns were measured. It was apparent that submicron particles were involved, which normal filtration would not remove. The next step in the process will require specialized testing to determine the particulate makeup. Knowing if the composi- tion includes oxidation byproducts, inorganics or carbon/soot from micro-dieseling will be critical in choosing the best method for removing it from the fluid. Depth media, electro- static filtration and a specialized blend of ion-exchange resins are some of the methods generally considered for varnish or submicron particle removal. Each claim to have advantages over the others for different types of particles. One problem with a 2,400-gallon reservoir is the turnover rate when utilizing side-stream or kidney-loop filtration. With most of these technologies, slower flow through the media or elements is required for them to work properly. A 10-gallon-per-minute system would only turn over the reser- voir volume of 2,400 gallons six times in a 24-hour period. Normally, with sideline or kidney-loop filtration, it is believed that seven times the reservoir volume turnover is equivalent to one-time full-flow filtration. To get ahead of the problem, it is suggested that a reservoir be turned over at least three times per day, which would require a large 30-gallon-per- minute system or several smaller systems running in parallel. In conclusion, the law of unintended consequences, which states that actions always have effects that are unanticipated or unintended, wins again. In performing an industry-ac- cepted practice of a high-velocity chemical cleaning and system flush, it was discovered that the system's age and buildup were a problem. Once the particle makeup is identi- fied, the source of the particles can hopefully be reduced or eliminated, and the process of cleaning the system can begin. Will this be a one-time cleanup or will the system require constant, specialized filtration to keep it in pristine condition? Only time will tell.