Centrifuging Waste Vegetable Oil

[Spencnaz]

I decided to start a new thread for this idea I had a while back.

In the thread 'shortening in WVO' several suggestions were put forth about centrifuging WVO to get the crumbs and assorted detrius out of the oil before processing into biodiesel.

Ok, guys. Fire away. Let's get a system worked out, the petroleum prices aren't going to get any lower. [img]/ubbthreads/images/graemlins/grin.gif[/img]

[Pu241]

ToddT,
Can you post any info you have on your waste water centrafuge you spoke of in the "shortening in WVO" thread here?

Spencnaz,
I once had the equations that govern the ability to separate different specific gravity/density materials via centrafuge. Let me see if I can find them [img]/ubbthreads/images/graemlins/shrug.gif[/img], and then we can see if a washing machine can be made to do what we want! [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

Thanks

Pu241

[RazzyB]

[ QUOTE ]
Ok, guys. Fire away. Let's get a system worked out, the petroleum prices aren't going to get any lower. [img]/ubbthreads/images/graemlins/grin.gif[/img]

[/ QUOTE ]

OK, firing:

I think that the energy required to get the oil spinning hard enough to pellet the contaminants, as well as the start-up cost of finding a workable 'fuge that would spin up at the required rpm's (I could work up the desired rpm's if anyone is interested), as well as the very low throughput (the largest floor model I've seen could take 6x900ml bottles, not very much oil) would make this a unideal situation...

I also work around microcentrifuges, tabletop, floor models, and ultracentrifuges daily...and I really doubt I'd want one in my garage...they scare me even when brand-new and with perfectly-balanced loads [img]/ubbthreads/images/graemlins/eek.gif[/img] Heck, even an unbalanced washing machine freaks me out [img]/ubbthreads/images/graemlins/tongue.gif[/img] [img]/ubbthreads/images/graemlins/blush.gif[/img] [img]/ubbthreads/images/graemlins/crazy.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

my $0.02...sorry to be a grinch!

take care

[350 long rod]

I have found that you can remove all the white nastys by filtering thru cotton or blue jeans.See pics here oil sample pics
I have made a basket to fit in a 55 gal drum out of welded wire fencing the 11/2 x 3 openings.then I picked up some tent dresses at good will the one I am using right now is a cotton poly blend.I cut the top off right under the arms and had my wife sew it closed.The basket is smaller by about 3in in dia and it is sitting on 2x4 on the bottom of the drum.I bent the top wires over the edge of the barrel then put in the cloth filter itis long enough so that the material is over the edge also then I put the band clamp back on to hold it all in place.I fill it up with the nasty white looking oil and let it drain thru.I have a whole in the bottom of the barrel and it is sitting on top of another 55gal barrel with 2x4 between them.when I get about a 1/2 of barrel I start the second filtering thru the blu jeans right now I just have a 5 gal bucket with a 1 in pipe out the bottom that the jeans are hose clamped to that is suspended over a 55 gal barrel.
Once a day I use a laddel to scrap off the fat from the sides of the first fillter .I am getting about 5 gal of sludge for every 20 gal of oil that is in the middle bottle.the worst part is scrapping of the sludge it can be messy.But it is worth it because the oil is so clean when you are done.After the levi filter then the oil goes in to a 80 gal hot water heater and is heated to 130 and cycled thru a ford car oil filter for a couple of hours.I then let it sit for 24 hrs drain off about a gallon and then presurize the tank and push out the oil thru a 5 micron wound filterelement the water filter type.then it is ran thru a 5 micron bag in to the trucks tank or jugs.The tube that I remove the oil from the heater from stops about 16 in from the bottom of the tank. hope you can follow all of that.
I am going to move my filtering from my shop to a empty part of our barn.I want to set up mutiple barrels that will filter in to a lage tank.

[safflowerpower]

Something that we have been doing in colville WA, is running the oil thru a cream seperator after we filter it at 50 mesh. We are taking out alot of white gunk and water out of our wvo. With you over in Western Washington you may be able to find a cream seperator from the dairys in your area. Also the oil filters on ships and larger boats, filter with centrifuging perhaps in the ship yards you could find one used. We are using a home dairy model, and we would like to increase our volume with larger centrifuges. We have to take out the baffels in the cone of the cream seperator to filter oil. It keeps alot of material of our filters.
Phil

[Spencnaz]

That is great news! I was thinking along those lines recently as you can use a centrifuge for honey.

I'll check here at the shipyards where I work in Ballard for a centrifugal oil filter.

[Pu241]

RazzyB,

Would have replied sooner but have been out of town and busy with the job!

Anyway, we don't need to "pelletize" the contaminates, we just need to precipiate them enough so we can pull off clean oil. Maybe take the "not so clean oil" left over, and collect enough to run it back through again to extract the maximum use from it!

[ QUOTE ]
I could work up the desired rpm's if anyone is interested

[/ QUOTE ]
I found the equations so I'm "playing" with them now, but your offer is accepted to cross check my own!

[ QUOTE ]
the largest floor model I've seen could take 6x900ml bottles, not very much oil

[/ QUOTE ]
No, these are laboratory models, I have worked with them too!
How about the sound it makes when one of the glass bottles collapses at speed!!!!!!!!!!!!! [img]/ubbthreads/images/graemlins/laugh.gif[/img]
There are monster industrial centrifuges, certainly beyond our means, that are used to "fuge" hundreds of gallons and hour continuously or smaller amounts in batches.
To the point, we can't hope to duplicate this capability, but as I see it we don't have to reach thousands of rpm's, we can if my interpretations of the equations are correct, get by with several hundred rpm's for a longer time!

What I would appreciate, if at all possible, is if you can centrafuge some sample oil (regular WVO from wherever you get your WVO)this would tell us, with some basis in fact, what the density of the suspended particles are, as well as, give us some idea of the required centripadel force needed to effect the separtion.
From this we can calculate what time it would take in a washing machine on spin. Provided we can find or measure the spin rate of a specific washing machine and a good approximation of the density of clean oil.

Otherwise some approximations can be made using the fact that some separtion occures just by letting the WVO sit for 3-4 weeks. This can be interpreted as being centifuged at 1g for (4*7*24*60*60) 2,419,200 seconds! Might just follow this approximation and see what it tells us!

Sorry for being long winded but I think this might still have merit.

Pu241

[T_Bone]

For a cheap centrifuge I would look at a used washing machine. It wouldn't be hard to convert it do want you want.




[img]/ubbthreads/images/graemlins/smokin.gif[/img]

[freds]

[ QUOTE ]
For a cheap centrifuge I would look at a used washing machine. It wouldn't be hard to convert it do want you want.




[img]/ubbthreads/images/graemlins/smokin.gif[/img]

[/ QUOTE ]

I did some looking at this a while back and the high end Centrifuges for pipeline processing are disk centrifuges. So I was thinking a large disk brake and a router motor.

[Pu241]

T_Bone,
[ QUOTE ]
For a cheap centrifuge I would look at a used washing machine. It wouldn't be hard to convert it do want you want.


[/ QUOTE ]

Wish I had said that!
Your very intuitive!

Pu241

[Pu241]

freds,
[ QUOTE ]
I did some looking at this a while back and the high end Centrifuges for pipeline processing are disk centrifuges.

[/ QUOTE ]

Not sure I understand how a disk centrifuge works!
Do you have links or an explaination?


[ QUOTE ]
So I was thinking a large disk brake and a router motor.

[/ QUOTE ]

Not certain a router could spin a large rotor up and if it did I'd be concerned if the rotor could hold together at 10, 15 or 20K rpm.
That said, maybe we can figure another way around using a brake rotor!
I think the router idea is good though, as they are readily available and can produce high rpm's. But I bet the rpm's drop quite a lot when you have something other than a bit hanging on the shaft!
Still an idea work looking into!

Pu241

[Spencnaz]

I was thinking last night of using a tesla turbine. For those of you who dont know what it is, it's a turbine composed of parallel discs on a common shaft. When these discs rotate, the surface tension of the fluid flowing through the discs pulls the fluid along with the discs.

A small turbine of about 5" in diameter was used to create about 300hp using high pressure steam! The only issue is that they are very tolerance critical.

Perhaps by using a high viscosity fluid such as veggie oil and powering the drive shaft of the turbine, a centripedal force would be induced into the fluid, slinging out the solids not captured by media filtration?

Just a thought, I've sketched up a view designs in the meantime on Solidworks.

[dbennett48]

Take a router bit and remove a carbide tooth on one side of the bit. Now turn it on and HANG ON. It will shake the daylights out of you. The speeds are too high (22,000 rpm) to risk personal injury.

Dave

[T_Bone]

Reading thru the responses, it appears that RPM seams to be the thought on how centrifuge works when in fact it's the different weight of fluids that causes them seperate and the RPM just acellerates the time that process takes.

A washing machine has several advantages. The foremost advantage is it can run out slightly of balance without distroying it's self. This could come in handy if one over fed the infeed pre-filter.

Just off the top of my head, I would think adding double fine mesh filter screens, one filter screen larger in diamater than the other, to the top of the spinning center post where the heated WVO would be first dumped into the inside spinning basket filters.

The water and oil being heavier would go thru the pre-filter first leaving behind the solids of the WVO in the first basket#1 screen.

The water and oil would then enter the second basket screen where the oil would continue thru the screen hitting the outer tub sidewalls thus dropping to the bottom then pumped out with the existing water pump to a holding tank for processing.

The water then would drop to the bottom of the second filter screen into a collector container where it's pumped out. This pump would have to be added but I think a cheap ($18) evaporator cooler pump could be used. This container and pump would be fixed in place to the top of the machine cabinet and would not spin thus no balance problems.

Until filter No.1 becomes full with solids this would be a continous orperation.


[img]/ubbthreads/images/graemlins/smokin.gif[/img]

[Sheboyganjohn]

Here you guys go for industrial centrfuge info

http://www.alfalaval.com/ecoreJava/W...p;languageID=1

We run two of them at work. The Alfa Laval we run can feed up to 12000 kg per hour with the process piping and pumps we use, the Westfalia we use can feed up to 9000 kg per hour with our products. I am sure they go much faster. They also use seperators in the brewing industry to seperate the various solids out of the beer. It is much to expensive to filter out solids at the volumes they run at.

As for how and if it would work with waste oil, I have no idea. I just know how to run them to seperate bacteria out of growth medium. [img]/ubbthreads/images/graemlins/eek.gif[/img] (food grade bacteria for the dairy industry)