Romaszewski Oil Bench Oxidation or ROBO test

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Saw Garak's post in Mola's latest quiz, and dug this up.

http://oil-additives.evonik.com/sites/dc...obo-reprint.pdf

Interesting bench test versus ageing oil in an operating engine...

Quote:
The test oil is combined with a small amount of iron ferrocene, a soluble iron catalyst, to aid oil thickening. This mixture is then placed in the reaction vessel and is heated to 170°C with vigorous stirring for 40 hours. During this time, a measured amount of nitrogen dioxide, simulating blowby gas and itself a powerful oxidant, is introduced over 12 hours to further catalyze the oxidation, or thickening, reaction. A subsurface feed of air is introduced to supply oxygen. Another extremely important parameter—application of a vacuum—mimics the volatilization of the Sequence IIIGA and lends to further thickening as light base oil ends are removed.
Iron ferrocene is added to the test oil to simulate the catalytic effect of iron found in used oils from wearing of engine parts. Iron has a catalytic (accelerating) effect on oxidation (oil thickening). So, iron ferrocene is added to ROBO test oil to simulate this. Why iron ferrocene? This form of iron is soluble in oil which is important so it can be available to participate in the oxidation (thickening reactions).


Reinforces my belief that varnish is produced in the windage zone of the crankshaft, with hot oil droplets exposed to reactive blowby gasses.

Questions that it raised in my mind

Does it support bypass filtration in keeping metal particles out of the bulk oil, reducing their catalytic action ?
40,000 miles is a big OCI, regardless of make-up.

Does it support the Mobil/Amsoil 12 months regardless of mileage stance ?
e.g.
low miles, probably means more warm-up operation, more blowby per mile, more sitting with these things in sump
versus high miles, where temps and time at temp are high.
 
Bypass filters catch the particles circulating in the oil and turns the filter into a catalytic bed. It doesn't separate the crud from the oil, the bypass filter just catches it and as we know lowers the particles in the bulk oil. Control of thickening will probably be additive or base oil corrected
 
What causes the varnish in your girls?
Well, obviously not from blow-by accelerated oxidizing.

Industrial turbine and hydraulic oils are replaced when
the insoluble particle count exceeds a predetermined limit.

Or the oil becomes un-serviceable for other reasons, varnish
as you mentioned before, being one.

Would by-pass filters extend the life of turbine oils in
steam generated power plants?

200 hours is about as long as I can push engine oil with an average
speed of 75 kph.
8,000 hours in an industrial application is not un-common.

I'm trying to lower my dependence on VIIs without spending extra
money on synthetics, but I can't have everything I would like
for $3.00 a liter.
Winter being the problem here.

Does the following sound reasonable?

Group 2,3 and 4 base oils cannot hold the varnish that originates
from VII permanently sheared.
I left out group one intentionally because you stated once that
when group one and two were mixed in a steam plant........
the group two could not hold the varnish created by the group
one turbine oil.
 
Pretty correct, the GrII and III (and IV) have lesser ability to hold (polar) varnish in suspension.

That being said, the GrI degradation rate is faster, but it can hold more varnish. GrII, in turbines tests well for a long time then can hit the wall quickly...seen it.

In a steam turbine, there are hot spots, potential arcing across bearings (we insulate some and earth others to stop that), static buildup in oil lines (oil behaves like a VanDerGraaf Generator) interaction with hydrogen, and of course mixed metals.

Monthly testing is oil properties, Particle Count and Wear metals. Quarterly oxidation life tests (RBOT)...had I stayed in turbines I would have been pushing regular RULER and membrane patch colorimetry...70,000 hours and things are starting to wear out on GrI, GrII hit the wall at around 40 before w worked out that they'd switched to GrII and not told us...they will blend GrI for us, just got to import it for the job.
 
Originally Posted By: HKPolice
Does anyone have a mirror of the PDF? doesn't seem to work anymore.
It worked for me. try this !!!
 
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