Finding the limits of my centrifuge and the sweet spot

[Mt_Man]

You must be registered for see images attach

You must be registered for see images attach

Pass 6 2.61oz. Really sticky slimy stuff. Feed stock was some synthetic blend gasoline piston oil primarily. Only think I didn't try was a pass with heat. Would be interesting.

I have to call it quits on this batch and start a new one. More data points to come. Same feed stock source. I messed with the ball valve I have for flow adjustment. Got it down to ~2gph. So we will see what happens.

 

[ut99dot1]

Hi,

Fuel, even from the gas station is never 100% clean. There's always some toleratable limit of amount of junk in there (see my 2nd post if you want to skip the theory).

The centrifuge works like this; heavier (large) particles get thrown a little distance (because they are heavy) and get stuck in the middle, while lighter (small) ones are light enough thrown further. Hopefully your oil/fuel is the lightest, and it gets thrown to the outside;

You must be registered for see images attach

After you filtered out the heavier ones, the light ones remain. Many many batches later, the weight of these particles might even be equal to the fuel, so you won't filter out anything at all (even though there will still be particles in the oil).

For example, if you start out with 1000 oz of junk, and you centrifuge is 75% efficent (25% is left)

pass 0: 1000 oz
pass 1: 250 oz
pass 2: 65 oz
pass 3: 16 oz
pass 4: 4 oz
pass 1: 1 oz

etc etc, this will never be truely "0", also note the biggest removal you do in the early passes (750, 185, 49, 12, etc see how its decreasing per pass).


Long story short, practically, I would draw a line to where the filtered oil's quality is "good enough". And then run it through a 1micron filter for good measure.

 

[ut99dot1]

And then what's "good enough". I have done some calculations and it appears to be if you are down to 2.5 to 5oz of leftovers, per 250 gal tote, for NON commonrail engines.

Understanding Diesel Fuel Cleanliness Standards

A walk-through of ISO 4406 fluid cleanliness standards, SAE/ASTM testing, filter ratings, and more in relation to fuel quality.

axi-international.com

"high pressure pump" : 18/16/13, so about 3000 particles per ml. If particles are 14micron each; you can have about 10-100grams per 1000liters. Which is +- 3.5 oz per tote. So if you get down to removing 5oz per run, and then filter with 1 or 5 micron, I would say its good enough.

So 3-4 passes, then filter through 5 or 1 micron filter.
Probably 1 to 2 passes + filter will be enough as only a fraction of the junk from the fuge are the damaging particles, and most being heavier fractions of the oil (which would be diluted anyways)

 

[Mt_Man]

Very interesting info. I usually go till hardly anything comes out in the fuges and then pass through at 1micron sock filter as QC. Been told it's overkill but, I like my fuel clean. I am learning new d2, oils, and other are not all that clean. So that makes me feel a little better. Lol

 

[Mt_Man]

Great link from axi-international, good find. I like the science and r&d of trying to figure all this out. I guess I would be happy if I could get 95% of the sludge out on a regular basis. Just wanting trouble free miles for years to come. I need to get a 1micron absolute sock for my QC. But another day. I would like to develop a good QC to make sure my finished product is what I like it to be. Along the road I would like to get the fastest way to process a batch to save time and electricity. At least that is my goal, streamline my process.

 

[ut99dot1]

Yeah and also consistency between batches, for me its really hit or miss. Some stuff I can almost immediately pour in directly, and other has lots of sludge in it.
My brother works in a pharmacy lab and they have some fancy microscopes that can count the particles (& determine their size);

You must be registered for see images attach

Something like this, super fancy stuff. I think for us it's more an "art"; you now have good feeling on what your fuge does and what to expect, so next time there's very little gunk from the first batch you might have a very clean lot, and do less fuge passes. Similarly when doing the last QC 1micron filtering, and what's left over there.

Also, nothing scientific but just out of my own experience. I run a Bosch VE pump (IDI) and these things are a lot tougher than you would expect. I had once no way to dispose the heavy sludge (bottom of the barrel), so I kept storing it, and after a while I had nearly a fuel-tank amount of that crap. I thought what the hell and poured everything in after filtering (5micron, which took ages). The car ran like ****, no power, to the point that it would die going up even the slightest hill. Also it was filling the entire street in a blanket of smelly, half-burnt oil/chemical odor. It was eye-watering irritating XD. Got flipped out many times haha

I actually managed to drive the tank empty, so got rid of all the sludge. However after that the 'problems' didn't disappear when switching over to the normal WMO-mix. Only diesel seemed to work. Taking stuff apart the fuel filter (& little metal wirebasket 'prefilter' in the fueltank) got completely covered in sludge. After cleaning everything out it ran normal again. So as long as there's no metal shavings in there I think it won't damage stuff permanently.

 

[Mt_Man]

New batch:
First pass 40.02oz
second 7.59oz.

 

[patrolgq]

New batch:
First pass 40.02oz
second 7.59oz.

How many gallons did you put through to get that out?.
Very interesting.

 

[Mt_Man]

It was about 275ish. I will look better in a few days but not quite 300g this batch.

 

[Mt_Man]

3rd pass 3.46oz
Doing a heated run for the 4th pass. We will see if it changes anything.

 

[Mt_Man]

Heated between 50-120f 4th pass 4.77oz. Slightly higher then pass 3 at 3.46oz.

 

[bbjordan]

That makes sense. Heating the oil reduces its viscosity and allows the crud to come out of suspension more easily.

I heated WMO with an repurposed dryer heater element. It worked good, but it may have been too hot. I found I reached a stage where every pass after the first few always had about the same amount slimy crud. I suspect I was causing my own problem with the high heat of the element. My brother figured it may be polymerization of the oil. The same thing happens to oil on baking sheets.

 

[kbenz]

I run my oil hot. Like just before boiling point hot