introduce air currents?

[gearhead]

Currently I am letting my oil settle for a week in a 55 gallon drum then I drain off the water at the bottom.Then I pump out 5 gallons of oil to be ran through a bowl style centrifuge twice.However, if the oil has a high concentration of water the oil has to stay in the centrifuge for much longer just to clean.The first pass through the centrifuge is full bore or how ever fast engine oil flows through a 3/8" hole under gravity.The second pass I throttle the oil to about 1-3 GPH depending on how wet the cake in the bowl is after the first pass. Lately however, I got some oil with a high water content and a month later I am still draining out emulsified oil with some free water.The net affect of that is the second centrifuge pass has to be slowed to about 1/2 GPH to get a good dry cake on the bowl which pretty much makes it take all day to make 5 gallons of fuel for my truck.So right now I am looking for ways to speed up the settling or water removal in the oil tank.One way I heard about is called headspace dehumidification.Dry air is forced into the tank and wet air is allowed to vent out.I am wondering if it would work better if that dry air was introduced at the bottom of the oil then allowed to vent out the top?right now I am just trying to get my batch time back down to about 1/2 a day because it sucks waking up at 7 to start the process only to pour the finished oil into the truck at 10 PM, in the dark...

 

[Shadetreemechanic]

heating the oil will help the water settle out faster. I run mine up to boiling point and let it cool before trying to filter it.

 

[Brad S.]

Do they (Headspace Dehumidification) have a "big" dehumidifier that gives them dry air?
Sounds like it should work, but getting that dry air during the summer could prove a little tricky??
PLUS that little thing of application of that kind of process?? A bubbler type device??
Thats still a good idea.

 

[gearhead]

getting that sorta of humidity in the summer shouldn't be a problem. Today's forecast 97*F 29% humility, tomorrow 93*f but thunderstorms...

 

[Blind Driver2]

I suggest finding a new source for your oil. I settle for a few days then 'fuge.

I've never had emulsified oil in my tank.

 

[Brad S.]

getting that sorta of humidity in the summer shouldn't be a problem. Today's forecast 97*F 29% humility, tomorrow 93*f but thunderstorms...

Ok, our humidity down this way is much higher than that. So you have the "dry heat" that should work, keep us posted.

 

[gearhead]

so far the bubbling looks promising.Set it up yesterday and there was a clear region of emulsified water on the airstone when I pulled it up after dipping it in the oil.After running a day the emulsified region is much less pronounced.Right now I just see a little bit of water droplets on the airstone rather than an emulsified region.I had to turn everything off today and seal the top of the barrel because it started raining.I built a little roof that sits on top of the drum that keeps water out,but with it raining the humidly would have been too high to do much of anything. Not bad for $20 experiment.

edit: it seems that bubbling didn't remove as much water as I thought.Turns it caused the water to drop out of solution,so when I opened the drain valve I got like a minute of straight water flowing out before a little bit of emulsified crap came out.Normally I open the drain valve and get a couple of seconds of water before emulsified crap comes out..

 

[Brad S.]

gearhead,
pics please. That sounds like something I could add to my dungeon lab,(garage)

 

[gearhead]

pics of what?my bubbler?My centrifuge,my black 55 gallon drum,my cat Tiny?


the bubbler is actually pretty simple its just an aquarium pump I got at walmart for $6, some airline, and a 10" blue airstone that gets dropped in the 55 gallon drum.