Some Q's about the centrifuge...

[area52]

Do you have a heater inline or how do you heat the oil? Or do you?

can you post some pictures of your setup?

 

[Stretch44875]

I already went the dieselcraft route. My dieselcraft centrifuge will be on ebay sometime in the next couple of months. Here's the thread on it, I am going to a motor driven centrifuge. Oil driven one works, but is a pain.

http://www.steelsoldiers.com/alternative-fuels/10416-stretchs-used-oil-centrifuge.html

 

[Avn-Tech]

Area52,

Currently I am not heating my oil. I did include a water heater element in my set up, so I would not have to redesign my set up to add one later.

What I may do to thin my oil, is mix 20% fuel in with it before I start filtering it.

I will post some photos next week, when I get a chance to go back out to my hanger.

Laterrrrr
Avn-Tech

 

[tennmogger]

This and the other thread have been exciting to read! I have a centrifuge, the type installed on big trucks to continuously filter the lubricant, but have not installed it yet.

I'm now thinking that setting up a fixed filter 'station' in the shop might be better. I could still filter the motor oil from the trucks, but could also filter such things as hydraulic fluid, waste oil for use in fuel mix, etc.

What would you experienced guys think about a 'batch' filter station that would use a sand blast tank, with air from the shop compressor, to filter a tank full of oil at a time? How much good would one pass through the centrifuge do?

This could be a very simple setup. No pump, no over pressure problems, no flow rate calibrations. Just fill the sandblaster tank (made to handle the pressure) with pre-filtered dirty stuff, put shop air on it at the recommended centrifuge pressure, and let it run until empty. Repeat if necessary.

The tank full could easily be warmed in the shop, or even have a small radiant heater aimed at it.

thanks for your thoughts...

Bob

 

[Yohan]

I disagree, I have been running WVO for years and it is MUCH cheaper than buying diesel. My setup took a few days to build but it works great and it takes me lees time (man hours) to run than it takes to cut my 1 1/2 acres of grass on a bi weekly basis. The bad is, it can be messy. the oil should be heated and run through the centrifuge, slow about 5-10 gal/hr. I get pretty clean oil and have already drained the settled water on the bottom so I just leave it running and do a 55 gal to a 55 gal transfer(gravity through the centrifuge) I do blend a little diesel but its anywhere from 5-20% depending on the temperature.

OK stampy, here is something a feller who has been making biodiesel for some time wrote me...

The centrifuge won't remove glycerin from WVO, that is a chemical process and cannot be removed by mechanical forces. The centrifuge is used to remove other impurities (food particles and water) from oil, but a chemical or high temperature cracking process is required to change it from vegetable oil into something else. Small percentages of used engine oil or vegetable oil which has been well filtered and or centrifuged can be blended with diesel or kerosene and used in any diesel without harm to the engine or fuel system. Higher ratios of used engine oils and vegetable oils can be used up to 100% if heated and injected into a HOT and well loaded diesel engine. For example a diesel generator can be warmed up running diesel, biodiesel, or fuel oil and once up to operating temperature and loaded 75% or higher can be switched to heated oils which decreases viscosity enough for the injection pump and injector. Here is a link to some good information on running with higher viscosity oils which have been heated to thin the viscosity.
http://www.goldenfuelsystems.com/

Due to the potential of carbon buildup and injector fouling with an under loaded diesel engine (idling vehicle or lightly driven diesel vehicle) I only plan to use this type of fuel system on a tightly temperature and load controlled stationary low speed engine generator system. (google "Listeroid 6/1")

I noticed in your post quoted above that you have been running WVO through your centrifuge. Are you removing the glycerin from the WVO or just cleaning it in the centrifuge? If you aren't taking out the glycerin, how long have you been running it through your engine? Do you also use WMO cut with diesel in your rig?

My initial question that got the above response was "can I run clean WMO (cut w/ diesel) in my 2004 Cummins powered Dodge without hurting the engine?"

Thanks for any info!

John

 

[m16ty]

Yohan, I think most people in this thread are talking about running WVO or WMO in multifuel engines. Multifuel engines can digest fuel that would kill most other diesels.

 

[BlueToes]

50/50 wvo/diesel

hiya. im runnin 50/50 wvo/diesel in my cucv and it's been workin great! smells like chicken on the grill . I take jugs from my mountain in the yard that have liquids in them at freezeing temps, ( like now ) and run thru homemade fuge ( 8" - 10" X real fast). I need to add a filtering system to begin with, because its a bit syrupy below freezeing. twin glowplug/hot water fuel heater b4 injector is makeing big difference as well.

 

[stampy]

Ok I agree that you cant take out glycerine...I said remove the heavies...including heavy fats and I too have made a couple of batches of Biodiesel and have the equipment and chemicals to do it so I understand the process and the difference. I have been running WVO in my Mercedes 300sd for over 4 years with no mechanical problems. I do try to cut my wvo with 20 % diesel but I will admit sometimes I don't. The car runs great. Most of my drives are short 5-10 min with the occasional 1 hr drive weekly. I have probably put 35 K on the car since I have owned it(guess). I am just relaying my experience. If I lived in NY Yohan I probably wouldn't run near 100% WVO as It's colder in the winter there...but in NC it doesn't fall far below freezing .

 

[stumps]

What is the concern about glycerin? There is no glycerin in vegetable oil. The glycerin only comes about as part to the saponification process used to chemically convert vegetable oil into biodiesel... and then because of the density difference, the glycerin readily separates out.

So, why the worries about glycerin?

-Chuck

 

[Yohan]

Thanks all for the replies. My lack of knowledge has led to the glycerin question! Stumps, my impression was that glycerin is present in waste vegetable oil when it is heated to cook food. If the glycerin forms during the process of making biodiesel, then burning WVO after "centrifuging" it is a moot point, ie; there is no glycerin there to harm the engine in the first place.

For anyone interested, here is a great site on making biodisel. I need to read more about the process to understand everything that's going on.

As for multifuel Vs. diesel engines, isn't it the shape of the piston head and burn chamber that makes a diesel engine burn using compression rather than a spark. I wonder what makes the multifuel so different? Just thinking outloud. Thanks again for entertaining my Q's!

John

 

[stumps]

Vegetable oils are esters of glycerol. Esters are the result of reacting an organic acid, with an alcohol. In the case of vegetable oils, it is acids like steric, oleic, etc. reacted with alcohols like glycerol. Basically, you can't have a vegetable oil without glycerol. Biodiesel keeps the organic acids, and replaces the glycerol with methanol... it modifies the oil to make a fuel that is more similar in characteristic to petroleum diesel.

Multifuel is a compression ignition engine with some interesting modifications. First, it has an extremely high compression ratio, around 22 to 1. Second, it has a combustion chamber built into the top of the piston... this chamber looks like someone used a broom handle to make a deep divot into the top of a clay piston. It is substantial in size. And third, the injectors inject a stream of fuel directly into the bottom of the piston's combustion chamber, not an atomized stream, but a liquid stream... more like that from a squirt gun.

Because the piston's combustion chamber is large, the MF engine needs a very long stroke to provide the needed high compression ratio. Because the piston's combustion chamber is a big hole dug into the top of the piston, there is more structure in an MF piston than a conventional diesel piston, making it rather heavy.

When the piston reaches the top of the stroke, fuel is squirted into the bottom of the piston's combustion chamber (keeping it from the cylinder walls). There, it splashes, and is heated by the hot piston until it evaporates, and ignites from the high compression temperatures. Because the fuel stream is substantial, and not atomized, the combustion can be controlled, and is away from the injector nozzle, keeping the nozzle cleaner. The combustion in an MF engine is slow, and controlled... regardless of the liquid fuel. That makes the combustion easier on the engine, and allows better utilization of the fuel.

Just about any hydrocarbon will burn in an MF engine. The only exceptions are those that flash at such a low temperature that they can't even get out of the injectors before they ignite, and those that are so slow burning that they don't complete combustion until after the piston has reached the bottom of its stroke (high octane aviation gasolines), and those that are so thick that the pump and injector cannot handle the goo.

It is not a given that any fuel you can burn in an MF engine will give you optimum engine life.

-Chuck

 

[PsycoBob]

As an addendum to Chuck's post above, there is some speculation on lubrication for the IP with certain fuels.

I'm in the process of assembling a rather, uh, 'large' WMO centrifuge system with a dieselcraft-style unit. Awaiting a mount for my hydraulic pump. I'll brag about it after I get it working.

 

[stumps]

As an addendum to Chuck's post above, there is some speculation on lubrication for the IP with certain fuels.

I'm in the process of assembling a rather, uh, 'large' WMO centrifuge system with a dieselcraft-style unit. Awaiting a mount for my hydraulic pump. I'll brag about it after I get it working.

Yes, that is correct. The IP gets its lubrication from the fuel. As I understand it, the MF injection pump is made of hard, polished, steel parts, which need minimal lubrication. Even gasoline is slippery.... many an old car has an electric fuel pump that is of the gear style, like an oil pump. They do just fine with gasoline as their only lubricant.... how the MF IP will fare with gasoline only is unknown to me. It certainly wouldn't hurt to add some motor oil to help it out.

If you check the manuals on the LD[T,S]465 engines, they say little about the desirability of the different primary fuels. Diesel is the first in their list, but gasoline is also in the list of preferred fuels. I have no idea what sort of life the military expected out of an MF engine, or its injection pump... I have seen some warnings from the era of the LD-427 engine that say to never use gasoline, except as a last resort...

My deuce's Continental MF engine's label says it is approved for all liquid petroleum fuels... a statement that is a little more inclusive than the label on the dash that lists the military fuels in the order of desirability.

-Chuck

 

[stampy]

I have always heard you need to add oil to gasoline as the flash point is too high and the lack of lubrication causes pump failure in a deuce so my . The above post by Stumps is the reason I only buy indirect injection diesels (as far as I know) they seem to be less prone to fuel issues......unfortunately they are also not as efficient. But I figure I waste about 1 hr per 55gal of fuel instead of about 3 (and the cost of methanol and lye) for biodiesel so when or if my Benz dies I will buy another for 1500$ (or less)and do it all over again. The biggest thing I will remind you of is WVO and Biodiesel WILL CLEAN OUT YOUR TANK AND ALL OF THE CRUD (on the tank walls) WILL END UP IN YOUR FILTER. So have extras...

 

[PsycoBob]

That cleaning action is good and bad... great for long-term, not so good for a sudden road trip. Most of the BioDiesel horrors I've heard of stem from snot clogging IP's or injectors. After it's fixed everything's cleaned out & nice and reliable.

I'm real curious as to how often I'll have to empty the rotor on my system. I'm using a Spinner II 76SE. Documentation is rather sparse on it's holding capacity, but it'll flow 2-2.5gpm. My tank is rated at 147Gallons, and I expect to baby-sit the little monster for the first cycle. As a minor note, with a few design changes, I could have a decent boiling-oil pressure washer.

 

[Yohan]

You guys are great! Thanks so much for the help. The more I learn, the more questions I have. Stumps, now you see how long it took me asking questions to get you to spill your guts!

Does anyone know if the NHC 250 in the 5 ton is a direct injection system?

 

[stumps]

Stumps, now you see how long it took me asking questions to get you to spill your guts!

Getting me to write stuff is easy, getting me to shut up is much more difficult.

If you want the nuts and bolts practical details of using alternate fuels, Stampy is your guy. I have been studying the use of alternate fuels for a long time, but Stampy has been out there actually doing it.

-Chuck

 

[stumps]

I have always heard you need to add oil to gasoline as the flash point is too high and the lack of lubrication causes pump failure in a deuce so my .

That high flash point is the entire reason for the MF engine's ultra high compression ratio. Gasoline just doesn't want to compression ignite... and when it does, its high octane makes it burn too slowly. It really hurts your efficiency if the fuel is still burning when the exhaust valves open and the piston has to start coming back up! All of that flaming fuel burning in your exhaust system contributes nothing to your forward motion.

I wish I had more access to actual studies on the MF engine and gasoline. I believe the MF is supposed to be able to run straight low octane gasoline without any problems... but I do not know this! There are spec sheets showing that the MF engine, with a properly functioning Fuel Density Compensator will give the same (approximately) HP running straight low octane gasoline as it will with heavy diesel. I'd like to think that is true.... but I don't know that it is, and I am not really interested in sacrificing my only deuce engine to the testing. I fix things that are broken, but I am not a big fan of breaking things that didn't need fixing.

I do know this, it won't hurt a thing to give your MF some oil or diesel to round things out and help lubricate the IP!

-Chuck