Water contamination generally consists of two parts, free water and emulsified or suspended/disolved water. Emulsified water contamination is fairly common. A centrifuge works very well on free water, and badly or not at all on emulsified or disolved water.
If it takes one day for my free water to settle out at 1G, I can make it settle out in 1 hour at 24G. However, think about the practical implications of your home-brew machine. Do you know how fast you have to swing a five gallon bucket to produce 24G? Scary fast. If the oil weighs 5gal x 7lb = 35lb at 1G, then it will weigh 35lb x 24G = 840lb when the centrifuge is swinging that baby around. I typically make a 40 gallon batch every two weeks, so that'd be a honkin' impressive centrifuge or I'd be making lots of smaller batches.
Industrial centrifuges, both batch and continuous, exist and work really well. But they are expensive due to the forces involved. To get free water out, it's a lot easier just to let it stand for a week or two and drain the free water. You still have to deal with the emulsified stuff though.
Good luck and have fun!
troy[ Parent ]
allan[ Parent ]
Have you ever looked into Lube refiners that were used on old semi engines, might still be used, not sure.
I think they were some type of centrifuge, spun out the inpurities from the engine oil as you were driving. Might be various types and not that up on them myself. I recall one from a mid or late 70's Freightliner I think. It leaked and was removed, not needed becuase of the trucks low yearly milage and oil changed each year.
Anyway I think it spun at high speed, dirty oil in spins around a few times, clean oil out, sort of a constant feed. Something like this may work well for removing free water and crud fast. Maybe 2 small tanks, tubing to near the outer end to feed in oil, so dirty oil goes in the outer end, spining cleans the oil, as more dirty oil enters the outer end the cleaner oil is pushed to the center and out a second tube in the center to the clean oil tank. Then you would need a way to clean out the crud also when you stop the spin cycle.
You could control the speed of the spin to what you want. Kinda like spinning an open bucket on a rope and the water stays in upside down, but it is not fast. Slower spin should work well, just not as fast as a faster spin. How long the oil spins could be controlled by how fast it is feed into the tanks. No feed and all oil tries to stay in the spining tanks, slow oil feed will push the clean oil out slow. Fast feed pushes oil out fast. If you have pretty clean oil use a fast feed, if you have dirty stuff, use a slow feed.
Only thing I am not sure of is how to seal the center connections where spining tubes would connect to non-spinnning tubes. That's always a problem for me, figuring out seals. Like when I build a inboard engine boat and run a shaft out under water, how do I keep water from entering the boat at the shaft?? Perhaps timing chain cover crank seals like for Ford 302 or Chevy 350? Though there realy preventing free leaks, no presure pushing.
That's kinda my thoughts on a centrifuge but to begin with I will stick to heating I think when I begin. I have plans for a heating system that won't use any feul, just build it in as one more part of my charcoal maker, black smith and metal casting setup. If I get it all built the way I plan, there will not be any waste heat escaping from anything. Each part uses heat for it's own purpose, start with the process that makes the most waste heat and feed the exhaust heat to the next process then the next etc... untill it is almost cool air escaping at the end.. nothing to lose
Spelin and tpying are my strong points, not electronics.[ Parent ]
Anyway, crank seals should work fine for containing pressure in a rotating system as long it's not a stupid amount. Can't speak to longevity, though. I've seen turbocharged 2l mitsubishi and nissan engines with crank seal leaks after 200 miles and they're VERY well built engines by US standards. (Not criticising US engineering by the way, just that big V8s can work with sloppier tolerances simply by virtue of being BIG.)
I've got a couple of bits in the pipeline for my hotrod which will need similar seals, so will let you know how it works. Assuming the wife ever stops finding me household jobs. lol'....If I even knew that I know nothing, that'd be something. But I don't!'[ Parent ]
It's amazing how bad North USA roads are with salt! I was born in Ohio. Anyway I have a nice conversion van (from Ohio), some body rust, not bad. The oil pan had 2 holes rust into it. I plugged them with epoxy, hope they hold till I can pull the pan and replace it. My starter just gave out when I was working on it the other day (not drove for about 1 year). Pulled the starter today, Geuss what, the starter case itself has some serious rust pits, the little cover over the top is rusted out, pieces missing!
I get alot of cars that had oil pan rust (not normally this bad) but so far with normal cars I have not had any with pressurized crank cases, though I mostly do older Fords, Chevy, Dodge, etc..
Anyway back top the centrifuge, I geuss it should not actually have much pressure on the feed line, and the outlet line doesn not even need sealed, it could just be one smaller line inside another larger line for the clean oil to run down and to a storage tank. Just a straight line with an L on the end that is spinning with the tanks and a larger not moving line it dumps into. So just poke in down in there and forget it :). nothing to lose
I'm wondering whether there might be some chemical you could add to de-emulsify any water, then centrifuging would be much more useful. They do it when they're making liquid pigments, so I suppose it's possible. Have to look that up.'....If I even knew that I know nothing, that'd be something. But I don't!'[ Parent ]
