AFFF in the bilge

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zarin1480
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AFFF in the bilge

Postby zarin1480 » Wed Jul 15, 2015 3:20 am

So, we have this lovely bilge foaming installation to percent the spread of fire, which is great. The issue is that this foam is a nightmare in the ows. Anyone got any experience with AFFF and breaking down the foaming so we can continue processing bilge water?

I've read everything from baking soda and vinegar to fabric softener to break down soap, but this is a little different than just putting liquid dost soap in the dishwasher.

Any tips would be great, because we're going to be flooding the bilged again soon and will need to deal with the aftermath....

On a side note, the foam does a fantastic job of cleaning the tank top, bilge wells, bilge tanks, and pipe systems!

Cheers,
Robert

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JK
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Re: AFFF in the bilge

Postby JK » Wed Jul 15, 2015 5:56 am

Why would you be flooding the bilge? Doesn't that get rather expensive?


ETA, I"m slow today, you have AFFF in the bilge already and will be having a water influx. You know, I'd be getting onto the manufacturer PDQ about what to do about this issue, especially if it is messing with the OWS. They would have the best answers. It may involve chemicals and a pump truck and some money thrown at it to clear it up.

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Big Pete
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Re: AFFF in the bilge

Postby Big Pete » Wed Jul 15, 2015 9:50 am

All the modern cleaning Chemicals we use in the ER, Quick Break, Clean Break etc are specially formulated so that they form an emulsion with oil for long enough to remove the oil from the surface it is on but split up again in the Bilge Tank, so that the oil and water separate so that the oil free water can be put through the OWS.

AFF is basically a powerful detergent, but a stable one that will not split, as you say, it will clean the Bilges extremely well, but unless you can split the emulsion you will never be able to discharge it through the OWS.

Three options:

Firstly (easiest) pump the lot ashore to road tankers.


Secondly, put maximum steam heating on your Bilge tank and boil off all the water, through the Tank Vents, transfer the oil residue to your waste oil/ sludge tanks and pump ashore as normal. Only practical if you can literally Boil the water off. Record the steaming process in the oil Record Book, IMO recognised this as a legitimate way of disposing of Bilge Water some time ago.

Thirdly, split the emulsion. There are two ways to do this, heat the Bilge Tank as hot as possible, (at least 90 Celsius) and keep it at that temperature continuously for several days before attempting to lower the Tank through the OWS.
The other way is Chemically, using a Flocculent, which will cause the oil droplets in the emulsion to join together again. There is a product for this in the Unitor/Wilhelmsen catalogue, but it is designed to be injected by a metering pump into the Bilge treatment system for maximum efficiency.

I would try heating the Bilge water first, then if that doesn't work on its own, heat the Bilge water and add Flocculent.

If that doesn't work then you are looking at expensive changes to the Bilge treatment system. There was a thread on this site about various methods of Bilge disposal, prompted by an Icelandic system of Conveyor belts with oleophilic brushes attached, I would have a look at that.

Some of the centrifugal separator makers have systems for separating oil from Bilge water/ sludge, but these obviously have a high Capital cost and involve extensive modifications to install them.

I am not sure why you flooded the Bilges with AFF, did you have an ER fire? Or was this required by Class or Port State? Usually the makers have a way of "Simulating" the release of the foam in order to comply with any Testing requirements from the authorities.

Good Luck with this, and let us know how you get on with the problems.
It is always better to ask a stupid question than to do a stupid thing.

zarin1480
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Re: AFFF in the bilge

Postby zarin1480 » Thu Jul 16, 2015 12:05 am

Thanks for the quick replies all.

The initial flooding was a live test during the commissioning. As with many projects, this failed miserably, and we are going to need to do it again soon once they figure out why it was not mixing the right concentration.

We tested the flocculent, and were met with limited success. It did allow us to process some of the bilge water, but did nothing to help the foaming. My next thought was to give the detergent something to fight.... More oil. We've got a few bilge wells that have a higher oil content, and just like with dish soap in the sink, enough grease and the soap breaks down.... If that fails, then it looks like dumping the foaming bilge water into the sludge tank and offloading is going to be the way to go.

Oh the joys of new, untested equipment.

Thanks again!
Robert

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Big Pete
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Re: AFFF in the bilge

Postby Big Pete » Thu Jul 16, 2015 2:43 am

Maybe you need to consult with an Industrial Chemist to find the most cost effective way of neutralising the foam?

Good luck.
It is always better to ask a stupid question than to do a stupid thing.

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JK
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Re: AFFF in the bilge

Postby JK » Thu Jul 16, 2015 3:42 am

OK, if you are dealing with the OEM and THEY have the adjustment wrong which has caused the issue.
Whoever is managing this for the Company needs to get after them because THEY have caused the problem. It is not up to the ship engineers to sort out this mess, only consult.
So the OEM needs to figure out how they are going to address their bilge problem and the problem they have caused in the OWS. Personally I'd be concerned about having to diassemble to OWS to clean it out to work properly or having to pump through it to flush it back into the tank. This is going to cost some money no matter what, to address.
I hope your Tech guy is tapdancing on their heads.
This is my take as a former Tech Super.

zarin1480
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Re: AFFF in the bilge

Postby zarin1480 » Sat Jul 18, 2015 1:54 am

Just an update for everyone who's been helpful...

The office decided that offloading is the way to go. So, next Vancouver, we get to pump out somewhere in the neighbourhood of 60 cubes of contaminated bilge water and sludge.

On the bright side, we can write off cleaning of the entire bilge system for both engine rooms, boiler room, and purifier room!

I agree with the general consensus that the vendor should provide a way to deal with the foam, but it turns out that another ship had the same issue, and they just accepted pumping it ashore.... Sad way to run a ship...

Here's an image of our Serep OWS falling miserably at processing the water.

Image

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JK
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Re: AFFF in the bilge

Postby JK » Sat Jul 18, 2015 2:15 am

About 10k to get it ashore.


For entertainment
http://youtu.be/wYAOHYKBYas


I was looking for a clip I saw years ago of a test where the foam spilled outside the hangers and covered a row of parked vehicles with the windows open. It was pretty fun, foam was everywhere.

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JollyJack
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Re: AFFF in the bilge

Postby JollyJack » Sat Jul 18, 2015 7:43 pm

Lovely stuff, it's used to clean oiled wildlife, gets grease right out of the way, its Dawn dish detergent!
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zarin1480
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Re: AFFF in the bilge

Postby zarin1480 » Tue Jul 21, 2015 8:21 am

Yes, it's done a fantastic job in the bilge system. Pipes have not been this clean since new build...

We're managing to process some of the water to keep from overflowing bilges and tanks, but in the end, ashore it goes. The worst part to be honest is that none of the higher powers in the company seem at all bothered by this.... Personally I would be tearing a strip off the vendor for overlooking this... Especially when it comes to light that this is not the first ship, and they knew about this problem! Lol


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