Bypass Filters removing Oxidation By-products and sludge precursors

[Gary Allan]

Now all we have to do is figure out how to make a useful product out of the residuals.

hmmm (thought cloud) ..want a new engine? Done dealer service throughout the warranty term?? Get INSTANT SLUDGE!! Just 1 quart of our used oil "extract" and your engine will be suitable for a rebuild/crate engine in no time. Satisfaction assured or your money back!

Thanks for the link.

 

[mjo]

I found a really cool article that explains in depth what oxidation,varnish, and sludge and their consequences are and also details the testing methods to find these. It makes for a worthwhile read:

Sludge, Varnish and Oxidation

Here are a few salient points I would like to recapitulate:

1. "When oil oxidizes numerous decomposition products are formed, including acids. Heat and the presence of metals such as iron or copper particles accelerate the process. So too, highly aerated oils are far more susceptible to oxidation. Primary oxidation products, known as aldehydes and ketones, develop (grow in size) through a series of steps (free-radical chain-reaction) to form polymers and other high molecular weight condensations. Eventually, the oil's viscosity begins to increase and the dense oxide suspensions can no longer be held in a stable oil-dissolved state. It is at this point when the oil is said to "throw sludge" leading to the formation of deposits and varnish."

2. "When passing a small amount of solvent-diluted oil through a one-micron membrane you will often see sludge and amber colored polymers present on the membrane surface"

3. "Additionally, some very dense depth-type filter media, often used as off-line filters, are said to have a strong affinity for carbon suspensions."

Toilet paper bypass filters are advertised to be depth-type filters and remove particles below 1 micron in size. From these excerpts, it would seem that any of the TP Bypass Filters can remove most of the decomposition by-products of oxidation and sludge precursors: acids, and polymers formed by oxidation of the oil. The article explained to me the reason why my used TP roll would excrete some very thick, black oil when squeezed.

 

[zanzabar]

http://www.machinerylubrication.com/Read/59/oil-analysis-varnish

Old link was broken.

So what is the consensus? Does bypass filtration remove sludge products? I'm using a Frantz bypass filter on a VW 1.8T going on the theory that it does.

 

[dnewton3]

Sure it will.

And so will a full flow filter. But not on the same size scale or in such percentages ...


I would also remind you that some amount of oxidation is a good thing, as it is the main contributor to the anit-wear tribochemical boundary layer. Established and discussed in great detail in Ford/SAE studies, not the least of which is 2007-01-4133.



What made you dig up a 7 year old thread with only two posts?

 

[zanzabar]

Originally Posted By: dnewton3


What made you dig up a 7 year old thread with only two posts?


It was the only one that came up on my search, and the link was not working any longer so I found a new one that did.

 

[Jim Allen]

It does. Especially particularly dense cellulose media, which I guess you could call a roll of TP. The synthetic filter may not as much because it isn't absorbent. The paper also absorbs a fair bit of H2O. I am using a Racor ABS bypass, which is an extension of the TP filter idea. It uses rolls of filter paper that is rolled to varying densities from top to bottom. Unlike the Frantz idea, they can calibrate the filter to deliver a specified performance, both on the efficiency side and the water holding. The ABS comes in 3, 5 and 10 um absolute densities. Thus far, nobody has been able to present me with any data on Frantz efficiency... which would likely be variable anyway according to the TP used.

 

[trees]

I'm new here, but as far as tp being used as a filtration material I would think that the thin, tightly wound, single ply stuff would be the best....

Think cellulose density...

And a roll of tp, like used in the Frantz, would be superior as far as depth loading went, I would think....

 

[Shannow]

The depth media use din industry for this purpose are specially made edgewise type that the oil passes from the outside to the inner.

Last year, I sponsored, through work, an undergraduate thesis that investigated color patch colorimetry on oxidising turbine oils, varnish theory, and removal.

Depth media, ion exchange, and electrostatics are part of the solution in industry...depth media is about all you can play with automotively.

 

[trees]

An interesting point to consider when evaluating a filter is filter flow type. Radial flow, or axial flow....

The Frantz type, or design, are axial flow. The oil is pushed along the filter media, and the particles are trapped within, or between, the layers. A roll of TP becomes pretty efficient as an axial flow filter.

I'm using NTZ filters, and they are radial flow. The oil is pushed through the paper media, not along it. The advantage is that the dirt cannot be pushed completely through the filter and out of it, which is possible with axial flow designs. You can run the NTZ until completely blocked, and it's efficiency increases as it becomes obstructed.

My last UOA had soot at .05 percent on an interval of 30k miles.