On site filter/purification of oil

[corey872]

Apologies of this is in the wrong forum, seems to fit here best, but feel free to move if I goofed.

Curious if anyone has input about the outfits who pull oil out of your engine, 'super filter / purify' it, then put it back.

Have the opportunity to save some cash in a HD Diesel fleet doing this. In a few trial runs, the UOAs of the pre and post 'purified' oil look good. Obviously, the micron sized stuff the spectrograph picks up goes through the process, and so does the oil additive package, apparently. Calcium, zinc, TBN, etc aren't really affected. However particulate count is substantially lower in all sizes after purification.

This 'seems' to have several advantages:

1. Cost, obviously - the purified oil is much cheaper than new.
2. Spectrograph history is maintained instead of 'wiped out' with the oil change.
3. Environmental - less new oil used
4. Time wise is about a wash as we're putting the same oil back to the specific unit. If we could always have one tank of 'clean' waiting, time might be faster, but spectro history would be affected.

My main thought, as long as a unit only has 'particulate' dirty oil, this might be a viable process, so long as visc, TBN and other additives are maintained at acceptable levels. Though with water or especially fuel contamination, it might be best to replace with new oil (as well as troubleshooting the original issues)

Though I welcome additional input/experiences from the guru's here.

 

[MolaKule]

For mone thing, the oil is simply filtered, not re-refined, etc.

Find out how they define "purified" or "purification."

Doe they refresh the additives that are needed for continued service? I doubt it.

I say let the used oil be taken to the waste tank and let the re-refining companies turn it back into GroupII oil.

Quote:
Spectrograph history is maintained instead of 'wiped out' with the oil change.


I am not sure what you mean by this. New oil analysis and trending is what is used to determine service history.

 

[corey872]

Thanks for the additional info. The purification mainly centers around removing particulate matter in the >1 micron size range. There is no additive refreshment at this time.

Perhaps 'wiped out' was a bad choice of words. Instead of the typical 'saw tooth' pattern where wear metals/contaminants build at a generally steady rate over time, then suddenly drop for the oil change, then begin to build again - this purification allows that process to continue, though it allows a longer time for the build-up.

The main issue with these engines - it is only feasible to change the oil at 6 or 12 month intervals. Removing the engine from service and shopping it outside those intervals just isn't feasible. So, while ideally the oil could be run until the spectro say it's 'dead', changing it at that exact moment isn't possible.

Prior spectroscopy has shown the oil can generally go 7-8 months before particulate contamination exceeds limits. Though it can usually go the full 12+ months and still have TBN and Viscosity at acceptable levels. This purification method is being considered as a way to cut the particulate load and allow the oil to be used much closer to the actual 'end of life' when TBN and VII are depleted, then it is changed for new oil at the 1 year interval.

In my estimation it would be somewhat similar to running an advanced filtration system...particulates are kept in check and the oil is changed when the additives are depleted. Though I was curious if other had any experience.

Thanks agaian for the input!

 

[bigjl]

They do this in Ghana, when I was over there in 2007 it was the new big thing. But then again you can make a nice living sending used engines there for resale as they don't seem to last aswell.

Wether this is due to the dusty conditions or rather sporadic maintenance I don't know but it certainly isn't going to have been helped by these oil cleaning type machines flogging on filtered oil with exhausted add packages.

My in laws managed to break a Daewoo Espero in 2 yrs, this was based on a very robust Opel/Vauxhall design that they rejigged and was as tough as old boots.

 

[Ken2]

You can only remove fuel contamination by dumping the oil. I'm not sure about antifreeze. Some filters can absorb and hold the water pending filter change. (I've had mixed results with coalescing filters designed to remove water, and never had good results in detergent oil.)

There are systems that slowly put some used oil from the system into the fuel and burn it while adding new oil to the running engine. This works.

A bypass filter that filters down to single digit micron range does a good job. The filter can be shut off and changed with the engine running for an essential stationary system, and changed easily on a truck. Centrifuges also add to oil life, but cleaning can be a bother. Oil analyses must be taken periodically and new oil added to bring up the additive content in the oil. The analyses are necessary to check for unfilterable contamination as well as checking the effectiveness of the filtration and the additive level.

If somebody is trying to sell you a package "purification" system to save oil, send him to your competitor.