Coolant in oil, can it be separated?

[Deuce_and_a_Half_Dragon]

Will a centrifuge remove coolant from waste oil? Inlay have access to a rather limitless supply of WMO from my former employer. The issue is, I know what got dumped into those tanks, had a few batches I dumped in from drop offs that were loaded with water, which I know can be separated with the 'fugue, but also allot of coolant. Will there be any nasty surprises when i pull the product out of the filtered barrel?

Jame

 

[patracy]

Coolant poured into oil that is only sitting separates. But the problem with engines that have blown head gaskets and ran for a while whip the oil up into a "milkshake". You'll be hard pressed to separate that.

 

[Phansm72]

I work for the ford and dodge dealership , I have access to all their used motor oil but it has coolant mixed in with it too. I have the same question! I wonder if it seperates like water or if it will mix?

 

[Kohburn]

the easiest way to remove the water is to heat the drum of the mixture and let the coolant/water settle to the bottom then drain it off.

 

[Deuce_and_a_Half_Dragon]

the easiest way to remove the water is to heat the drum of the mixture and let the coolant/water settle to the bottom then drain it off.

Will a centrifuge just milkshake it then? I don't know if I'll have a heat source for my drums right off the bat, so heating may not be an option for a while

 

[Kohburn]

someone else will have to answer than one - my setup is just a heated tank with 3 stages of filtration including a racor water seperator.

 

[dmetalmiki]

KHOBURN help

could you detail your setup please? I have access to WMO also.. but have had too many suggestions as to how to filter it down to (what?) microns. so if you could explain the "kit" and method that would be greatly appreciated. My 9 trucks wait (hungrilly ) in advance of your knowledge!

 

[G-Force]

You can only break an emulsion in mineral oil with heat. To properly centrifuge the oil you'll have to get the oil up to about 90 to 95 degrees C in order to get any and all impurities and water out of the oil through a centrifuge. If you run oil cold through a centrifuge you will not get the separation of solids out of it. And yes, if you run oil with water cold through a centrifuge you will create an emulsion.

One way to do it without a centrifuge is to heat the drum and then let it stand as Kohburn stated and then decant the oil off the top. This will be the cleanest in the drum. The hard part is finding the interface between the oil and water.

 

[Phansm72]

I talked to the guy at the dealerships , and he said there is a ton of coolant in the oil in the big holding tank, what he suggested is me leaving a few 55 gallon drums there and all the techs will put the ATF in one and motor oil in the other. Sounds like a plan to me!!

 

[Yohan]

You can only break an emulsion in mineral oil with heat. To properly centrifuge the oil you'll have to get the oil up to about 90 to 95 degrees C in order to get any and all impurities and water out of the oil through a centrifuge.

I have a Q about this: Speaking of strictly waste motor oil that's contaminated with water and/or anti-freeze, if one heats the mixture up to say 100 degrees F, would the water and anti-freeze evaporate out od the top of the drum?

And let's say that you just get it up to the 100 deg. F temp. and don't necessarily wait for anything to evaporate; would you say that the centrifuge would then seperate the water and anti-freeze from the oil since it is now heated?

Thank you for any info on this!!!

John

 

[woodywood]

antifreeze is a oil base i have tried a batch to get it out heated of course!in order to get it hot enough to evaporate the antifreeze you would have to have it over 200 degrees which i wouldnt recommend heating it that hot cause you have a chance for a good fire!i normally heat my oil to around 160-180 degrees f.with good results with water in it!try to stay away from antifreeze!

 

[russ132]

I have had good luck seperating water with my seperation tank but have not tried antifreeze. I have access to alot of oil with possible antifreeze contamination but I just do not know the answer to this. Great thread.

 

[grayw0lf]

2 simple things you can do: Wait patiently & let gravity do its thing.

 

[G-Force]

I have a Q about this: Speaking of strictly waste motor oil that's contaminated with water and/or anti-freeze, if one heats the mixture up to say 100 degrees F, would the water and anti-freeze evaporate out od the top of the drum?

And let's say that you just get it up to the 100 deg. F temp. and don't necessarily wait for anything to evaporate; would you say that the centrifuge would then seperate the water and anti-freeze from the oil since it is now heated?

Thank you for any info on this!!!

John

Sorry Yohan, I just saw your post. Water will settle to the bottom of a tank as will antifreeze. Heating it to 100 F will not make it evaporate off because the oil is on top of the water so it cannot evaporate. It will help any water or antifreeze in suspension in the oil to separate and drop out. But higher temps will make it happen faster.
Standing water (water sitting at the bottom of a tank and not in suspension in the oil) isn't really a problem. That can be taken care of by draining it off.
Its the fine water droplets that are in suspension in the oil in the form of moisture. You get enough moisture you can see it as an emulsion. To get rid of the water droplets you have to heat the oil. When you heat the oil you will change the viscosity of the oil which will make the oil thinner and thus the water will have an easier time of separating out of the oil and dropping to the bottom of the tank.
The specific gravity of oil is between 0,8 and 0.9 at 60 degrees F. This is lighter than the specific gravity of water which is 1.0 at 60 degrees F. The specific gravity of ethylene glycol is 1.3 at 60 degrees F. When you heat the oil and change the viscosity it makes it easier for the fine water droplets that are being held in suspension in the oil to separate out from the oil. However, you don't want to go over the boiling point of water (212F).
The best way to get moisture out of oil is to heat the oil say to 150 F and spray it into a vessel that is under a vaccuum. The vacuum will lower the boiling point of the water causing the water to evaporate.
The other problem after you removed the moisture is the cool down. During this time the oil will have a tendency of picking up more moisture from the air that the oil is exposed to. You won't pick up much but you will pick up some.
Oh yeah..... the boiling point of ethylene glycol is around 250 degrees. You really don't want to boil off antifreeze.

 

[rattlecan6104]

A lesson I learned the hard way..

My deuce will run on a SMALL ammount of antifreeze mixed with oil, we are talking about 30 gallons WMO to one gallon antifreeze with really no noticeable power difference, just the exhaust smelled kinda funny.

My deuce will not run on a mixture of coolant and oil that is so strong that it looks nearly tan in color, until the engine finally dies, the truck will act like its filters are clogging, then you will have to pump the tank, change filters, and clean out the filter bowls... not much fun.

with this info presented to you all, keep in mind it is a situation that happened to me and that I AM IN NO WAY RECOMMENDING CUTTING YOUR FUEL WITH COOLANT. I just happened to get lucky with the little bit in the tank, not so much with a lot.

On the topic at hand...

What I have typically done is along the lines of what the others have said, let it sit, and pump the contents out of the bottom, after every few gallons take out a little bit for a test sample, put a lighter to it, then do the same to some WMO you know is good. when the reactions are about the same you should be good. Never hurts to cut with a little diesel if you are still a little concerned.

 

[Yohan]

Thank you G-force. After I posted, I realized how high I'd need to heat the oil to "boil off" antifreeze!

With my gravity feed set up for centrifuging WMO, I think I'll add a tap at the bottom of my drum and use it to decant any water and antifreeze I might run into. I have been getting some pretty clean WMO so far and will try to keep it that way. Thank you for the input!

John

 

[W.K.Lowe]

Ok im an aircondidioning tech. and we use a vaccume pump to get the moisture out of a cooling system especially after we opened the system up and changed something, any way if you could get a 55 gallons of UMO under a verry low vaccume(100 microns or less) wouldnt you be able to extract the watter out? Thats how we get the moisture out of the compressor oil and the refregerant.....just a thought.

 

[supermechanic]

WAY to much thinking on this subject.
1. Put suspect mix,(co-mingled oil/anti) in a drum with a drain at the bottom,let sit.
2.Open drain.
3. When anti stops flowing and oil shows, close drain.
4. What remains is oil.
5. Decant from top.
My shop has been using waste oil heaters for 30 years with this process, no problems.

 

[kastein]

You should likely also heat it after doing as supermechanic said. If you heat it to a fairly high temperature (say 220 degrees or so) and keep it that way, almost all the coolant will boil out. Heating it to a lower temperature and drawing a vacuum to lower the vapor pressure of the water will also help.

EDIT: I see this has been covered already and will not work. My apologies!

Also, is ethylene glycol soluble in oil? I can find info on propylene glycol but have not yet found solubility info on ethylene glycol. If it is soluble, this could be a tough one...

 

[shovelheadmike]

In the power industry, we use cengrifuges a lot to keep lube oil pure. They ALL have a very large heater up stream of the centrifuge for that reason, but also because they are much more efficient with heated oil.