Milky diesel

[Lepke]

There are two kinds of diesel additives. One helps the filter system expel the water and the other will help the diesel absorb the water so it can be burned. And it could be too much additive.
It really sounds like a water problem. Could be water and air if your polishing pump is cavitating. All the Racors I have used have heaters built in. Besides a better burn, it helps separate the water in cold climates.

[sailmaryann]

Originally Posted by MartinR

Actually a water emulsion looks like Ouzo......

Biodiesel in the fuel or some kind of detergent contamination would help keep the water in emulsion.

Yes I understand that. I have now stopped polishing, and am starting to heat my 700 liters, 20 liters at a time in jerrycans...

What I still don't get however is why a stable water emulsion would clear up at 40 C, and remain clear. There have been no detergents in the tanks, and I doubt that there was a water leak via the filling bungs, as I have the same situation in both tanks, not conneceted and with different bungs (I have changed the o'rings some months ago, and have tested with kleenex that there is no water infiltration when it rains hard... ).

Yes I know, I'm puzzled too...

Will report on progress.

Thanks for the help!

[boden36]

I know this sounds very makeshift but have you thought of making a temporary fuel line and routing it around a warm component so that your diesel feed is heated above the critical temperature? If you do, use the suction side rather than the pressure side!
Once you have used up the tank, then go back to the standard feed.

Regards,
Richard.

[thinwater]

Originally Posted by sailmaryann

What I still don't get however is why a stable water emulsion would clear up at 40 C, and remain clear.

Actually, that is quite normal. I'll skip the chemistry, but it is an effect used by fuel recyclers everywhere.

[DeepFrz]

But does the fact that the fuel becomes clear mean that the fuel is safe to burn? It still has a very high water content.

[MartinR]

Actually, emulsions are available as fuel in some parts of the world, for environmental reasons, as the water reduces NO2 emissions, so they are fairly safe to burn. And deliver better energy also.

I haven´t seen the fuel, but if it looks bright and clear after heating I would use it. This type of engine is not very sensitive. And it is probably not so easy to get rid of the fuel ashore.

I can still not understand why the fuel emulsified in the first place.....

[DeepFrz]

Originally Posted by MartinR

Actually, emulsions are available as fuel in some parts of the world, for environmental reasons, as the water reduces NO2 emissions, so they are fairly safe to burn. And deliver better energy also.

I haven´t seen the fuel, but if it looks bright and clear after heating I would use it. This type of engine is not very sensitive. And it is probably not so easy to get rid of the fuel ashore.

Can you provide a link to scientific information on this?

[a64pilot]

Originally Posted by DeepFrz

Can you provide a link to scientific information on this?

Water injection has been used since well before WWII. Water in the combustion process is usually beneficial, not detrimental.
Biggest issue with an emulsion of water and fuel is if the water phase separates, then of course you have water to deal with, and water can be very destructive both long and short term.
Actually now that I think about it, the gas you buy with Ethanol in it has quite a bit of water in an emulsion with it
I have no idea about Scientific papers, I'm basically a mechanic.

However I don't think its water, it is something I think that is coming out of solution, possibly paraffin or something similar. If you have ever ran bio fuels in a Diesel engine this effect is quite common and you have to have a fuel heater before the fuel filter.
It is similar to cooking oil, the stuff turns solid at room temperature but is clear and thin with just a little heat.
This is usually not an issue until much colder of course

[MartinR]

Originally Posted by a64pilot

Water injection has been used since well before WWII. Water in the combustion process is usually beneficial, not detrimental.
Biggest issue with an emulsion of water and fuel is if the water phase separates, then of course you have water to deal with, and water can be very destructive both long and short term.
Actually now that I think about it, the gas you buy with Ethanol in it has quite a bit of water in an emulsion with it
I have no idea about Scientific papers, I'm basically a mechanic.

However I don't think its water, it is something I think that is coming out of solution, possibly paraffin or something similar. If you have ever ran bio fuels in a Diesel engine this effect is quite common and you have to have a fuel heater before the fuel filter.
It is similar to cooking oil, the stuff turns solid at room temperature but is clear and thin with just a little heat.
This is usually not an issue until much colder of course

And paraffin clogs the filters, but otherwise is not detrimental to the engine. But correct, at 30C it should not be an issue. The melting point of paraffin is around 37C, though. My problem with this is that the sample was tested negative for biodiesel, so where should the paraffin come from? VGO contamination, maybe.

Anyhow, and this is a personal opinion, I would use the fuel if it looks clear and bright after treatment. Both water emulsion, paraffin or FAME (biodiesel components) are very unlikely to damage the engine.

About scientific literature, google "emulsified diesel fuel". There is plenty info. At work we use water injection into the combustion air for our diesels for NOX reduction. And the ratio is 20% water to diesel! The reason emulsified fuel is rarely used, is that emulsions are hard to keep stable, especially with temperature change.

[DeepFrz]

Actually, water in diesel fuel can do a job on your injectors and your HP pump. What I don't know is how much water mixed with the diesel fuel it takes to destroy your injectors or your HP pump. A normal amount of 200 ppm vs. the measured amount of 4500 ppm is a huge difference. Or so it seems to me. I don't know if it is harmful or not. That is why I am asking these questions. So far no one has had a satisfactory answer and I haven't been able to find a satisfactory answer so far on the internet at large.

[MartinR]

Originally Posted by DeepFrz

Actually, water in diesel fuel can do a job on your injectors and your HP pump. What I don't know is how much water mixed with the diesel fuel it takes to destroy your injectors or your HP pump. A normal amount of 200 ppm vs. the measured amount of 4500 ppm is a huge difference. Or so it seems to me. I don't know if it is harmful or not. That is why I am asking these questions. So far no one has had a satisfactory answer and I haven't been able to find a satisfactory answer so far on the internet at large.

Actually 50PPM is normal amount, 200PPM is maximum allowed.

Water by itself kills the injection pump. Injection pumps need fuel for lubrication, water has zero lubricating properties. Diesel fuels today also contain lubricating additives. But emulsions are safe, as both the fuel and lubricants are present. Just for information, emulsified fuels normally contain about 13% (130000PPM) water. They work without problems. The problems come when the water separates in the tank, and enters the injection pump without fuel for lubrication. But the Racor filters should take care of that. Needs observation, though

Modern common rail diesels are much more at risk here, as pump engineering tolerances are much less, and they operate at higher pressure. This is also the reason why lubricators are added to modern diesel fuels.