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Oil as a service

Swapping out waste for profit with SKF RecondOil

Updating outdated and often wasteful industrial practices will be vital in tackling today’s pressing environmental challenges. Inefficient use of valuable non-renewable resources simply won’t cut it anymore and the widespread use (and misuse) of industrial lubrication is a significant part of the problem.

Time to rethink lubrication

Almost 40 million tons of lubricant is used every year, of which 45 percent is smeared on industrial machinery. This amounts to around 19 million tons per year! Additionally, its carbon-heavy production and shipping processes show that its supply chain simply isn’t sustainable and its toxic, physiochemical nature makes it harmful to anything around it if disposed of in landfills or bodies of water – which is far too often the case. Rather than treating lubricant oil as a single-use consumable, it – similar to the remanufacturing of bearings and other components – should be able to be regenerated.

Over and over again. And it’s not only the environment that benefits. The use of clean oil can bring substantial performance improvements and longer machine life.

Industrial seals, especially those used in hydraulic systems, are most effective when pumping or being lubricated with “clean” oil. If the fluid becomes contaminated or incompatible with the chosen material, the follow failure modes can occur:

  • Change in seal material volume – “swelling” or “shrinking” and the impact on seal contact force and friction
  • Hardening and embrittlement of the seal material
  • Softening, loss of strength, or dissolving of the seal material
  • Crosslinking or degradation of polymer chains, which can cause the material to fatigue or lose resilience

Nanotechnology: the answer?

Fortunately, double separation technology (DST) is a method SKF can perform to restore used oil back to almost factory condition, having a positive impact on the environment as well as an operator’s budget and bottom line. The system uses nanotechnology to clean the oil for reuse and can reduce overall oil consumption by about 90 percent.

Here’s how DST works: After an operator’s machinery has been examined, high-performance fluid oil is introduced into it, along with a unique booster chemical which attracts nanoparticles (metal filings, dirt, etc.). Following this, they are separated from the oil and filtered out. This results in clean oil ready to be used again. The DST oil regeneration system can be implemented or retrofitted in almost all kinds of industrial equipment which require oil for lubrication.

Want to hear how SKF enjoys “endless opportunities” since installing one of the first DST systems in its deep groove ball bearing production machinery? Watch this video and find out.

Putting DST test

Testing oil cleanliness requires acknowledgement the ISO reporting standard ISO 4406:99. This standard categorizes microparticles into different levels based on their size: greater than 4 microns, greater than 6 microns and greater than 14 microns. Although it is DSTs specialty and most beneficial for prolonging oil service life, the eradication of particles smaller than 4 microns are not considered by ISO.

SKF’s European seal testing center in Judenburg, Austria, is where the performance of RecondOil is evaluated. This is performed on the same rigs used to test rod seals as part of a hydraulic system.

Heavy-duty tests are performed in two cycles: The first cycle is a moderate 10-day test which runs for 200 km at an oil temperature of 80°C (200 bar pressure). It is used to check the oil and the seal performance under common application conditions. The second test cycle, with an increased oil temperature of 110°C for 60 km (315 bar pressure) is used to evaluate the top limits of the hydraulic system. Data is collected via the test benches many sensors.

Oil needs to be changed regularly to make sure that tests fairly represent customers’ operations. If the same oil is left in the system, this will obviously have a negative impact on sealing material and render test results unusable. Yet, when it comes down to evaluate the effectiveness of DST, only half of the oil is removed. The other half is sent to SKF RecondOil’s DST center for regeneration. Upon its return, testing is performed alongside a benchmark of untreated oil.

DST: Does it work?

Results revealed that DST-regenerated oil had positive effects on seal performance, especially when it came to seal friction. The tests highlighted a clear correlation with reduction in friction by using DST-regenerated oil, which in turn will reduce machine wear, reduce potential for cross-contamination, and extend the life of the oil in service. The table below reveals both treated and untreated oils’ effect on friction.

The team that performed these tests recently put together a detailed report of all its procedures and findings. The whitepaper is available here, at the SKF RecondOil microsite!