Algae In Fuel

[flyu2there]

Probably the simplest cure to is a frequent change in fuel filters until the junk disappears that, of course, coupled with frequent use and more fresh fuel should work. I know that many marinas have the equipment to polish fuel which is nothing more than running it through a series of very large filters each finer than the previous and returning the fuel to the tank, sans additives. The process is supposed to clean the tank as well because of the high pressure of the fuel pumped back in stirs up the fluid and the process is continued until no debris is found. Caution here, polishing can also be interpreted by some as adding a jar of some kind of "snake oil" which in the final analysis may or may not work I can attest to the filter polishing, while I have not used the process on my bus, I have used it on boats. It takes longer than one may think, I do believe it took several hours to clean 200 gallons of fuel from my sailboat. I think I last filled that tank in the early 90's and it is still full....but that's a sailboat.

I do believe the the ultra low sulfur fuels have a lower cetane rating which may explain that issue, that can be overcome with a cetane boost. Alkyl nitrates (principally 2-ethyl hexyl nitrate ) and di-tert-butyl peroxide are used as additives to raise the cetane number. Look for it on the label.

Finally, jet fuel. Kerosene comes a bit higher on the cracking tower and with the exception of anti icing inhibitors I have never added anything to it. I would guess that I am personally responsible for burning at least a couple hundred thousand tons of that stuff and never a problem....however no jet sits on the ground very long.

[flyu2there]

JIM,

John, there is an awful lot of information here causing overload for me! Did you wright the article? If so I have some questions, if you don't mind.

I did not write the article it is in my library under fuel

The article states what is going on and happening in the fuel system and to the storage tank and warns of the dangers of additives to the fuel for prevention of the situation, but it does not offer any suggestions for the cure or prevention of the situation once it has taken over ones vehicle for instance.

My best guess is that long term sitting is the root cause and that sitting may well be in a storage tank rather than in your fuel tank; fuel, like everything else, breaks down to a degree with age. I think it is safe to say that it is prudent to only by fuel from providers who serve up copious amounts of the stuff, Flying J, etc.

Preceding the article you mention fuel polishing, is that the only remedy you know of?

Yes, of course frequent use would probably be preferred. I suppose the fuel could be drained and refilled with fresh as another alternative.

What methods are used in the aircraft environment to prevent the situation?

It does not appear to be an issue with turbine powered aircraft, although all a/c fuel providers have strict filtering requirements prior to dispensing. A jet engine is not nearly as "fussy" as an internal combustion engine. A jet will run on peanut oil, coconut oil, paint thinner, rubbing alcohol, Vodka (probably 100 proof minimum), whatever as long as it is clean enough to pass thru the fuel control unit and the fuel nozzles. We have a Dodge Diesel P/U Truck at the airport, since we have had it it has run very well on Jet A although the exhaust aroma is perhaps peculiar....Jet A does work in diesel engines although there are probably some other issues that develop in time

Do jets require their fuel system be cleaned out thoroughly every so many hours?

Yes and No. Most turbines are on a progressive maintenance program components are changed at regular intervals regardless of their condition rather than "on condition"; I might add that there may well be many thousands of hours between component changes. I do believe water is a bigger issue with jet fuel as more often than not tanks are only partially filled and condensation can be a problem; the jet engine doesn't seem to mind water but the fuel indicating systems do. All jets are usually sumped every 24 flight hours (Part of an A Check) to remove excess water. As I recall, most turbine fuel systems are filtered down to around 10 microns however the filters will by pass if they become clogged, the engine will contine to operate normally but it may well trigger a component change. As mentioned earlier, Kerosene is a higher refined product than Diesel so it appears not to be as big an issue.

If this fuel contamination (algae) is such a wide spread problem do you have any idea why the fuel is not formulated to prevent algae and or keep it more under control?

I think as the article indicates, it is the normal aging process of diesel fuel. Gasoline when left for long periods will varnish up the fuel system although the no lead thing has reduced that plus there are additives that help, Sta-Bil and the like. Again, in diesel fuel, it is NOT algae in the fuel, can't happen. It is junk that forms as the fuel is affected by a whole laundry list of items (mold, bacteria, water, corrosion, heat and age)..as they mentioned in the article, kind of like milk turning into cottage cheese. It is probably sage advice to carry at all times some spare fuel filters but aside from that, other than being aware, there is probably not to much one can do save use the bus. I have no doubt that there is something akin to Botox that could be added to the fuel at manufacture however it is probably a cost thing and for the most part has prooven to really not to be a huge issue

[PrevostNewbie]

I have a Powertech 17.5 KW, and a Racor 500FG S/S. Looks like the filter comes in 2, 10 and 30 micron. Which one do you recommend?

[Gil_J]

10 micron if it's your only filter, 2 is unnecessarily too fine, and 30 is used for primary filters.

[Fratto]

I would think that the Racor was the primary filter and there would be a spin on secondary fine filter.

[PrevostNewbie]

I do have a secondary spin on, i am using the Donaldson P550127 for the secondary, it says it is a 17 micron? Seems kinda high is that incorrect for a secondary? I replaced what was on there.

[Gil_J]

17 micron secondary on our generators is not surprising. These are old school very forgiving engines. It still would be good to check the engine manufacturers specification.

[Fratto]

I thought mine was 10 ... but honestly, I dont remember ha! That seems to happening more every day