[C4ENG]

I am experiencing an interesting bit of info on how most people feel a fuel separator will work. In my experience I have seen that the fuel separator will separate out mosture in the fuel and seperate out other sorts of foreign duprey such as algea and things of the such in the process. However in the process of seperating the moisture it just happens to collect some of the algea and duprey that causes you to have to clean out the bowl and yet still passes that duprey through the machine clogging your fuel filters. As far as I would be concerened the seperator is not designed really to clean out the duprey but only the moisture in the fuel. Most people feel it is designed to clean every thing (foreign duprey) out of the fuel. I would appreciate hearing other peoples experiences on this matter.

[CaptTom]

C4,
Let me throw my mechanical prowess at your question. A diesel fuel filter/separator unit not only separates the water from fuel, but does filter algae and foreign particles before they get into the fuel components (ie pumps, injectors). Water is separated and settles to the bottom of the fuel filter unit. The valve at the bottom of the filter is to let out that water. Since water is heavier it will settle at the bottom, in the bowl. The filter element's job is to stop foreign matter. Filters come in various sizes, usually measued in microns. The smaller the micron number, the finer the filter and thus the smaller the particles to get trapped. When you get algae or foreign duprey in the filter bowl, then it's time to change the element. Trapping matter is not just a by-product of separating water, it's one of the most crtical jobs of the filter. And if the filter gets clogged, your flow of clean fuel will stop and the engine stops. Fuel is not bypassed around the fuel filter like it is with an oil filter.
Now if you are talking about a fuel separator that does not contain an element (like the separators that spin the fuel so the water drops) then there should be a filter unit before to prevent the algae from getting to the separator.
I have seen filters that had no water but clogged by the dead algae (that's what you get when you use a biocide in the fuel, the algae dies and collects at the bottom of the tanks) and therefore shutdown the engines. One step to alleve this is to have the fuel "polished", or run through a series of filters to clean the fuel so you don't get significantly clogged filters. This is also good if you had to buy fuel from unknown sources, that may contain dirt or water. Some yachts have fuel polishing systems onboard, others call in a service from time to time and have the fuel polished at dock side.

[C4ENG]

Tom
Thanks so much for your input of knowledge there.
I believe I may have left out a very important bit of info in my origanal post. I was refering to a mechanical fuel separotor such as the all mighty Alfa Laval brand name separotor.

[CaptTom]

I thought you may have inteded that after I wrote most of the reply, but left the response there as it may help others. I haven't used the Alfa Laval separators, but now curious and will do some research (as well as keep an eye on this thread).

[K1W1]

Hi,

A mechanical centrifuge will not clean out 100% of a Microbiological Infestation.

The cladosporium resinae microbes can pass through the centrifugal process and get into the fuel filters where they continue to grow and multiply.

If you are finding that you have problems with this a first step remedy is to slug dose your remaining fuel stocks with a Fuel Biocide, There are several on the market I like Biobor because it come in handy sized cans and use a product called Amerstat 10 from Drew Ameriod when I cant get Biobor.

Once you have knocked the bugs off a lot more will separate out in the bowl and what's left will pass through your filters and burn in the combustion chamber.

You should also try to remove as much of the free water in the bottom of the tanks as possible as it is in the interface between fuel and water that these little things thrive.

I don't know what model of separator you are running but I have seen a plastic bowl liner( I can't remember if it was Alfa or Westfalia) that allows for a quick bowl clean by just yanking it out and chucking it away, you still have to clean the disc stack but it definitely saves time and mess.

You can further improve the condition of your fuel by throttling back the Separators throughput and batch purifying all the time. Unfortunately a lot of boats are not set up for this so you have to transfer fuel around with the Seperator to run it through it, a process that requires a lot more user input than a simple recirc to and from the same tank.

Don't forget once you have it under control to continue to use a Biocide as part of your housekeeping and fuel management program.

If your problem is really severe the only proper way to get it sorted is to have someone come along and take all your fuel off, centrifuge it, put it through a polishing filter and clean your tanks before returning it onboard. Don't forget to change all your fuel filters and blow out the lines if it is really bad.

[rzaccone]

In the interest of learning more about polishing. Do they charge by the gallon?
Does the same company typically clean the tanks as well?
Any other questions to ask these companies to make sure we're getting the right providers?

Seems having this done prior to a sale may be a good selling point.

Thanks

Ralph

[Castlerock]

How do these system compair to the Algae-X units we have on our boat?

[K1W1]

Hi,

In my experience Fuel Polishing costs are based on quantities, I just did a quick Google for polishing rigs and found a pretty interesting site here

http://www.gulfcoastfilters.com/fuel_polishing.htm

The one I have had the most personal experience with was a unit running an Alfa Laval MAB 103 Separator and a Filter full of plates packed with Fielders earth as a filter medium.

It used to clean the most badly contaminated fuel very well but needed a lot of cleaning itself whilst in operation.

The Algae x things have been around in one form or another for the best part of 20 yrs. Some say that the enhanced benefits are smoke and mirrors others swear by them.

I will say one thing for those type units though not neccessarily that brand. I was working in a workshop in 1992 and a Customer was complaining about problems with choked filters etc. He wanted to try one of the Magnetic Units the company sold but wasn't convincved it would work. He and the Boss worked out a deal whereby he would pay full price for it and if it didn't work the boss would give him back double his money plus remove it and put everything back the way it was.

That guy became the greatest living advert for that little workshop.

I was on a De Vries Boat that used these (http://www.fuelking.com/en/index.html )things on Mains and Gens I am not convinced that they actually did much.

[TSI AV]

Hi,

1. Have You asked abt fuel oil or diesel oil ?
a) if fuel oil (IFO)- then separating temperature should be at 90-95 degC.

b)in case of MGO / MDO separation temp. is appx 40 degC appx.
For some reasons - this fact is forgotten 9 of 10 times...

2. Don't forget: Separator can work in two modes: clarifier and purifier.
one eliminates only impurities, another - impurities and water. This can be done by replacing of gravity disc and top disc...
Please also note - separator capacity (throughput) has to be as low as possible (just enough + a bit more to pace up with engine), then it is most effective.

*Regarding Alfa Laval: They make an ALCAP system, or SU- types, both are very advanced.

3. The best solution - clarifier + purifier, what are switched in "series".

4. I agree with K1W1 - if You got small, irritating animals in fuel USE BIOCIDE !!! try out Drew, Unitor , Vecom. They all have a solution. My best experience - Drew Ameroid.

5. "Bio" problems are becoming worse, if fuel tank is stand-still (not shaken) and when fuel is "getting older".

6. Do not forget to drain settlings daily !!!

rgds,

Andrei