Dave, thanks for the www.lakos-laval.com website. I asked them to send me a catalog. Hope to see what that baby costs.

The spinner works on the idea that heavy stuff will be separated by the G force of being spun. Can't you just do the Dave UK thing and let it sit for a while and don't drain off the bottom. Or are we talking about large quantities and the need to process quickly.

Hey, I heared that in McDonalds they throw sand in the fryer and the junk in the fryer gets pulled down with the sand. Anyone here have experience with this?

Einstien founded his theory of relativity on his observation that acceleration and gravity are indistinguishable.

For my needs, I was originally hoping that a centrifugal type filter would superclean used vegetable oil, without the expense, and waste, of oil with low micron filters bag filters. It is my belief that fine filtering (1 micron absolute), as advised by some filtration specialists, is best. Still, I don't think this has been proven as a neccessity. However, with waste vegoil as a fuel seeming to be somewhat a new science, I figure that erring on the side of caution is prudent. If something goes wrong, (ie dirty injectors, heads etc.) I would like to know for sure what it is NOT due to, so I can figure out what is wrong easier.
Economics comes into play also. Fine filters cost about $5-$10 each. I think I would be using enough bag filters over 5 years to justify the cost for a $500 centrifugal filter (and the spinnerII has a reputation for lasting 20+years), especially considering the current hassle of traveling 1 hour to buy the bag filters from a one-man business with unreliable hours working out of his home(s). Counting in the wasted oil along with the bag filter, I figure that if a centrifuge can clean down to 1/10 th of a micron if desired, then a centrifuge would be better than bag filters for filtering AFTER the water wash/settling process.

I have to agree with Dave on this on (for once). Gravity for filtering reigns supreme for me. It is free and does not clog up, ever! This is how it is done, and I have had no filter clogging problems whatsoever since changing to this method:
1)Use a large vessel, preferably (stainless or aluminium) with to outlet taps at the bottom. One should be about 50mm higher than the other.
2)Have an electric heating coil on the bottom of the container or a gas flame underneath.
3)Fill up the first 40mm of the container with water.
4)Add 80% WVO, 15% Kero and 5% Mineral Turpentine
5)Turn on element (or flame) and let the water boil. The steam will rise through the oil and condense out again, at the same time heating up the oil as well. By doing so it removes all water soluble impurities from the oil. The thermal convection caused by two liquids of differnt specific gravity, churns everything up. No need to stirr.
6) After 10 minutes, turn off heat and let everything settle. The water and particles sink to the bottom and the Turps disolves the animal fat out of the oil. The Kero is there to increase the cetane number of the oil and to keep it thin enough for the pick up in your fuel tank. During summer, you might skip the kero or use less of it depending what oil you start off with.

After it is cooled down (12 hours later to let gravity do it's thing properly), you have three layers in your tank: Dirty water, animal fat, and clean oil. Drain off the oil from the upper tap, put into tank and drive off into sunset.
P.S. Mix up the animal fat with sawdust, and fill into empty milk cartons. Makes excellent fire bricks for the heater. The burn for up to 1,5 hours.

Uli

That's the best description and method I've seen on the web.
I like the idea with the turpentine.
I'll change my method accordingly.
By only heating and filtering, the now liquid fat passed the filters, too.

Thanks, Uli

Interesting, Uli. What kind of micron filter do you use, what size and type of filter (ie I use 1 micron absolute 7" by 32" bag filters). How much oil do you process before your filters need to be changed?
I prefer not to use any dino (kero) especially because of the localized pollution from my genset, but also because I prefer not to support the fossil fuel cartel. Do you think biodiesel could be substituted in your process instead of kero?

FYI: I use a gravity/water wash method with good results too but don't have noticable problems with any animal fats, so I don't see that I have a need for turps. I go about 300 gallons before I feel the need to change my filter.

Hi Trev

In answer to your questions, I do not use any filters at all. Only the method I have discribed. I would not call it just water washing either, but rather steam cleaning. The hot steam, undergoing a phase change to liquid within the oil, becomes highly reactive in doing so. That is why it disolves so much crap. The water which settles at the bottom at the end of the process, has the color of weak coffee. I am planing to PH test it soon, to find out how much acid it takes on.
Sure you can use biodiesel instead of kero to cut it. Anything that brings down the viscosity to accaptable levels. As for the fat, I know that the fat makes excellent fuel, but in winter(below 5 deg C) it tends to settle out at the bottom of the fuel tank. This clogs up the pick up tube in the tank. I have asked a chemist the other day what would be the best method of sepearting animal fat from veg oil and he said: Freeze it out. That is excactly what happens in your tank. You can easeily try this by putting a glass jar with oil/fat mixture into the fridge. A few hours later you will have a white and rather thick layer at the bottom of the jar and clear oil on top. We can learn a lot from chemists. it prevents us from reinventing the wheel,

Uli

Uli, steam cleaning makes sense to me. I can imagine how steam would get the crap out quite well. Cooling also is a good idea, as I read (on the web somewhere) that is how the fuel companies winterize their fuel: something like bringing the fuel down to it's cloud point and then filtering the wax/glycerine(?) particles out.
What concerns me is the final micron particle size in the oil: how can you be sure that there are not particles that are not going to dirty/clog/wear your injectors/pump/cylinders etc? From what I hear, the fuel companies filter their diesel down to 8 microns (here in Canada at least). Knowing that some high performance after market filters do down to 2 microns (say injector specialists), I wonder just how important for good combustion etc, is fine filtering?

Has anyone got knowledge of the relationship between fine filtering and clean combustion and/or pollution?

One good way to ensure that the floaties settle out properly, is to give them time to do so. By putting the steam cleaned oil into a glass jar you can observe how long it takes to get completely clarified oil. It may take several days. My suggestion is to prepare a series of 20 liter oil cans (ther ones the stuff comes in when you buy it) and add outlet taps about 5 cm (2 inch) from the bottom. Stockpile your pre cleaned oil in these containers but leave them for at least a week before using the oil. By that time, everything, and I mean everything will have settled to the bottom. Everytime you use one up, you add another processed can to the beginning of the chain. Should work well.

Uli

Gravity works about "98%" for me. However, I am told that I can't see the microscopic particles that can still hurt my engine. Uli, Have you tested your filtered oil to check for microsized particles or do you assume your fuel filter takes care of them? If so, what micron size is your fuel filter and how many miles approx does it last before you need to change it?
I feel a little uncertain about letting a large amount of 5-20 micron size particles travel through my injectors etc, especially since I believe that engine mounted fuel filters are merely a safety device meant to get the large particles that accidentally contaminate the fuel - eg. rust from the tank etc- not to clean the fuel (ie the factory cleans the fuel to 8 microns and it seems to me that they would go only as low as they can get away with, but the fuel filter catches particles often only 20 microns in size). I am lead to believe by a filtration specialist with some involvement in vegoil as a fuel, that for example, used vegoil could be saturated with 20 micron sized carbon particles that would clog injectors, increase cylinder wear and pollution etc. Even though the oil looks clean, and passes through a stock fuel filter, that fuel may not be so great for the engine or the atmosphere?

http://www.ssengg.com/clofc.htm
http://www.tfhudgins.com/spinner/spinner2.html
http://www.separationequipment.com/marine_centrifugal.htm

[This message was edited by Karl on 16 August 2001 at 11:04 PM.]

How do these filters work and are there any good diagrams out there? I know that if I understood them better and could actuall see one then there is no doubt that I could make one cheaply.

Do washing machines have the ability to perform the task? They are cheaper and more plentiful.

Washer machines spin up to 800 rpm, but centrifuges like the one at spinnerii.com goes something like 6000 rpm. The faster it spins, the lighter (ie smaller) the particles that can be removed.

CalJoe, have you had time to try out that spinner? (no pressure!)

quote:

centrifuge

There is a company in Ontario that sells a centrifugal cartridge filter - in the car. It is called SPIN-CLEAN. Check it out here:

http://www.dieselproducts.com/spinclean/index.htm

quote:

As for the fat, I know that the fat makes excellent fuel, but in winter(below 5 deg C) it tends to settle out at the bottom of the fuel tank. This clogs up the pick up tube in the tank.

This is why I use a heated fuel pickup. There I live all wvo is solid for at least 4 months of the year so filtering fats out was not adn option. A heated fuel pickup allows me to use any oil..and hot filteing really makes the process MUCH simpler/easier/faster.

quote:

Has anyone got knowledge of the relationship between fine filtering and clean combustion and/or pollution?

No real effect on combustion. Filtering is nearly exclusivly to protect the close tolerance IP internals from wearing out prematurely. If your stock filter is 10 micron then adding a "high performance" 2 micron filter is only have one effect..you will have to change filters more often.

Whatever happened with the results of the Spinner II filters purchased by a couple of the forum members. It seems to me if the centrifugal filters work onboard the vehicle and filters to a tenth of a micron, then it would take the guesswork out of wondering whether wvo sources have more or less water in their oil. I understand that somesort of prefiltering is desirable, but wouldn't it save time of the weeks of settling as well as the cost of bag filters??

Here is a link to a paper by a physicist that says there washing machine spin cycle turns at 640 RPM (slow, most info pages say 800 to 1000 RPM) and creates 114.6 G'S.

Spin cycle "G" force calculations.

I would think this would make a dandy rotating filter by adding a filter bag inside the spin basket and pouring the oil into it (maybe remove the agitator), The oil should be forced through the inside layer of surface crud and then through the filter material then through the perferated spin basket and be collected in the outer tub. the normal washing machine pump should move the cleaned oil as well as it does water. At 114-to-1 a one hour spin would equil almost 5 days of settling.

I will try this eventualy, by letting this spin long enough almost all the oil should be forced out of the crud and the crud should be an almost dry cake of material, just shake out the fabric filter basket. This dry crud cake would be a big improvement over handeling the gooey crap I am now cleaning out of my 3-stocking strainer every 10 gallon or so of oil.

Filter cloth available "by-the-yard" from Mcmaster-carr (here, raw material, fabric), page 3251

---------------------------------
Polyester, Polypropylene & Nylon Fabric

Polyester Fabric
Fabric can be used for filtering water and various coolants (water soluble, synthetic, and light oil) in metal polishing, grinding, finishing, and honing operations. Use on filter systems driven by gravity, pressure, or vacuum action. Can also be used to filter air, petroleum, and beverages (not micron rated). Color is white.
Rayon/Polyester Blend (Snofil)— An economically priced material used in gravity coolant applications. Maximum temperature is 180° F.
100% Polyester (Reemay)— FDA compliant media with high wet and dry strength. Used in liquid and dry filtration applications. Maximum temperature is 300° F. When used for FDA applications the maximum temperature is 212°F.

Ivoryman, my Spinner II is mounted and ready to go. However, I keep adding bells and whisles to my setup and so I am perpetually "just one week away" from making 100 gallon batches. Nuculer