Ultra Fine filtration and additive stripping

[GeorgeCLS]

A while back I withstood humongous fury from several board members for my relating additive (namely VI Improver) stripping with the use of a 1 micron beta 200 filter in a real world application. And that it appeared to be VI improver stripping which the oil formulator of the oil shared can be as large as 5 microns, thus the viscosity issue.
With shrieks of horror (from 427Z06 and others) indicating that my statements were a complete impossibility as many folks had been using 1 micron by-pass filteration for years with no problem. And I replied that the supposed 1 micron filters were really not 1 micron beta 200 filters, thus the non-issue on additive stripping..
The negativity was so intense that it was no longer worth the time and aggravation so I stopped participating in the group... That is the background for:
This quote is from Noria's monthy newsletter and it discusses some of the issues we were talking about regarding 5 micron and smaller oil filtration and as it relates to particle counts. Which, for one method of particle counting, is a form of ultra fine filtration.

"We are constantly debating the issue that one cannot accurately particle count new fluids because of additive interference. This is particularly true with 15W40 diesel engine oil. The VI improvers and others argue that the dispersants seem to be the main issues. Do you know of a process to eliminate this interference in order to accurately particle count this oil or multigrade new fluids?"
You are right, some additives can interfere with the particle count. Perhaps the biggest offender is the silicone defoamant, which is not dissolved in the fluid but rather suspended as microglobules in the 5 to 10-micron range."

I do not have the author's name but this question/answer appears in day's Noria's e-mail. Irrespective, it certainly lends credence to my original statements regarding for real ultra fine engine oil lubrication and the possibility of stripping additives...
George Morrison, STLE CLS

 

[Gary Allan]

I don't think anyone said that you were FOS, George. It was just that they weren't going to just blindly accept paradigm altering data off of the internet from one source in one instance. There is plenty of justification for the skepticism.


For example: You're insisting that Beta 200 is absolute. Ok, let's move this up a notch from the former Beta 75 ..which has been considered absolute in most instances that I can recall. Let us even go to the lower beta numbers ...20 for example.

Now let's just take a Beta2=20. In a full spectrum of particles from 1um through 100um ...95% of those 2um and larger will be eliminated in a multipass test. That leaves some variable amount of ALL particles ..larger and smaller.

That is, one would surely reason that if Beta 200 stripped VII ..that Beta 75 surely would too. You're talking 4.95% difference between Beta 20 and Beta 200.

Tell me you don't see something to question here

None of this impugns your work ...only the validity of the conclusions derived from one source with limited data points. Surely worth further investigation ...big time.


..but that being said ...thanks for the follow up.

 

[GeorgeCLS]

Impugn is one thing; to be called wacko is quite another... Sharing my real world experience with a caveat that we would note write a paper on my experience did not justify the level of acrimony expressed by my least favorite person. That said, please note the statement indicating issues with a SINGLE PASS with engine oil for particle counts.. That is not multi-pass.. Given the stated issues with single pass particle count and additive problems, I rest my case with regard to 5 micron and below multi pass with 1 micron beta 200 and 1000 filtration. Vs. porported 1 micron bypass filtration which was very likely 30 micron beta 200 filtration calling itself 1 micron filtration...
That was my original premise... That yes, there were no issues with engine oil filtration with these filters as they were not even approaching 5 micron level filtration, thus no issues with additive stripping......
George Morrison, STLE CLS

 

[Gary Allan]

Quote:

---

I rest my case with regard to 5 micron and below multi pass with 1 micron beta 200 and 1000 filtration. Vs. porported 1 micron bypass filtration which was very likely 30 micron beta 200 filtration calling itself 1 micron filtration...

---

In all candor, George, you're fully entitled to be satisfied with your conclusions. There are still questions that are unanswered that have validity in, at least apparently, discounting this still. I don't think that my challenge here is outrageous or unreasonable. You may not have my answers ..but I would hope that you, at least, acknowledge the validity of the question.

Take this Donaldson filter sitting before me.
P165354
Efficiency Beta 2 (Micron): 2
Efficiency Beta 20 (Micron): 3
Efficiency Beta 75 (Micron): 5
Application Note: SYNTEQ Media #2

Let's assume that they're liars and just move the beta numbers down a grade. We'll say that the beta 75 number is the beta 20 number and the beta 20 number is the beta 2 number. Is that enough to compensate for their "wishful thinking"?

That would mean that 95% of the 5um and larger particles are filtered with this media.

Surely one would reason that additives that fall in that range aren't going to magically exclusively fit into the 5% that makes it through.

It would also mean that 50% of the 3um and larger particles would be filtered. That would mean that at least half of the
Doesn't that sound reasonable or unreasonable depending on how you're looking at it?

I don't quite get your single pass/multipass reference there. If it's in service, it's either going to filter or it's not. The difference is only in where you choose to take your numbers from. That is, it only changes the apparent results in testing.

I was hoping that Schultz would be on line with his testing facilities to give us a definitive threshold for additive filtering. His access to membranes down to .25um would really put the matter to rest in a clinical manner.

 

[GeorgeCLS]

Regarding your comment "I don't quite get your single pass/multipass reference there. If it's in service, it's either going to filter or it's not. The difference is only in where you choose to take your numbers from. That is, it only changes the apparent results in testing."

In pore blockage ISO testing, it is essentially duplicating a "single pass". The lab is saying they are getting skewed results due to additive stripping in just a single pass through the pore blockage material. My comment is relative to filter ratings which are based on multi-pass averages. In a word, no, when one runs a liquid through a filter on a single pass, the filtration which occurs will not be close to what the multi-pass provides. Which is to say that with that much additive filtering occuring at 4, 6, and 10 microns in ISO particle count testing, then a multi-pass true filtration would significantly increase the amounts of ultra fine that were filtered.
There are actual conversions available to approximate the decrease in performance for a given multi-pass filter rating vs. single pass. All filters are rated for multi-pass. Some filters (very few) are rated a step higher for not only multi-pass but also varying pressure and flow rates.

George Morrison, STLE CLS

 

[Gary Allan]

Oh, I agree that a single pass test typically shows a lower capture ratio than the multipass test.

No two ways about it, in automotive filters there's lots of manipulation that can be done on the test conditions to give a desired result.

..but none of that should alter, one way or the other, the ability for a given filter to strip out additives. As I said, even a Beta2=5 should be (very quickly in service) stripping out additives. 50% in some number of passes ...and 50% of the remainder in subsequent passes up until the filter is saturated. It should even get somewhat better as it approaches saturation. We should be able to apply that to just about any filter even if it only has a Beta20=10. Some % of 1um-9um particles are going to be filtered to lessor beta numbers.

Again, I'm not disputing your, or your lab's, results. I'm just trying to rationally integrate it with some sensible correlation with stuff that we see every day.

 

[GeorgeCLS]

Gary, what we see every day is essentially 30 micron filtration.. It is as simple as that........Thus no additive stripping whatsoever... And not much in the way of filtration either...
George Morrison, STLE CLS

 

[Titan]

You guys are talking about one thing, allow me to throw another item into the mix...I don't know enough about your world to know if this has a fit. Red Blood Cells are somewhere around 7-8 microns across...but, they are elastic (at least the youngest ones are), and can change shape to squeeze through capillaries that are smaller. Could these molecules you are referring to be similarly "adaptive", and squeeze through the pores, so that a 5 micron molecule can actually traverse some 1 micron pores?

 

[oilyriser]

Adsorption could hold back a %age of an additive.

 

[GeorgeCLS]

Yes, there are many components in engine oil, such as soot, that are adaptive and very difficult to filter. My quote from the Noria publication was indicating that there really are components in engine oil that are as large as 5-6 microns and ARE filtered, even on a single pass through a pore blockage setup. (4, 6, 15, 25 microns) Which is to say that in a multi-pass filter setup of a 1 micron beta 200, a good amount of additive stripping will occur in short order.... Given that the pore blockage screens generally used are 10 microns, if additive clogging is an issue with a 10 micron screen, well, then, a 3 micron beta 200 filter would certainly do some stripping.....
However, this is all academic in that there ARE no 3 and 6 micron commercial oil filters available; thus no problem..
The Amsoil EaO is very effective to 10 microns then reduces efficiency dramatically; i.e. an excellent cutoff point and no issues/minimal issues with additive stripping..
George Morrison, STLE CLS

 

[Gary Allan]

Got me swinging on that one Titan

Basically I have to still say that my jury is still out on this matter. Although I can accept that something occurred, there's a lot in sensible implied extended effects that are not apparent in light of this revelation. Any filter (probably) filters to the single digit micron level to some very small percentage. This percentage would (rationally) increase the finer the filter was designed. The notion that filters rated @ 5um and 10um or even 20um are all actually 30um just defies the entire industry and effectively makes them all manipulators and liars.

I've been asking for the most modest of concessions on this issue and keep coming up empty

 

[GeorgeCLS]

Gary, I would not want to use such strong a term as "liars", but I must say that in my real world experiences I have replaced a 3 micron beta 200 filter from a brand X with a filter of the same rating (but rated using a varying flow & pressure beta ratio)from company Y and the follow on particle counts dropped two ISO codes. One ISO code cuts particles in half..
So, not lying, but in the 'real world' of filtration, there are many filters that are rated a 3 or 6 micron that do not achieve that level of filtration in that the filters were rated at constant flow, pressure (as per the ASTM test procedures), while in the 'real world' of hydraulics, engine oils, etc. fluids vary in pressure, flow rates, viscosities, all of which can cause a filter rating to be a wonderful laboratory rating but worthless in the real world...
So, the manufacturers are NOT mis-representing their products. They are stating the level of filterability in a laboratory test in lab conditions. It is just that we do not have laboratory conditions in most filter applications..

Which is why I was anxious to test the Amsoil EaO filter in a 'real world' environment to determine how it really performs with all the variables..
George Morrison, STLE CLS

 

[oilyriser]

Small pores could temporarily trap long molecules, too. It would be harder to filter snot than corn syrup, though they seem to have similar viscosity.

 

[harry j]

Quote:

---

Which is why I was anxious to test the Amsoil EaO filter in a 'real world' environment to determine how it really performs with all the variables..
George Morrison, STLE CLS

---

George,
How is the 10,000 mile Eao test going?

Harry