Automatic Draining of Water from Diesel Fuel

The only thing that comes to mind is a float switch weighted to lie on the interface of the oil and water, heavier than the oil but lighter than the water. When the water reaches a preset level the pump runs for a preset time.

Agree but the difficulty will be finding a float that will distinguish between diesel fuel and water.

It is a matter of density. A hollow ball with enough weights attached to make it lighter than water and heavier than oil. You might have to separate a section of the separator to quieten the turbulence.

Think of the Galilean Thermometer. The difference is that you have a well-defined interface between the water and the oil.

It may be uneconomical to attempt fuel treatment during bulk transfer; instead consider centrifuging/filtering the fuel between your storage tanks and the usage point.

Are you sure there are no alternative suppliers?

No, we are locked into a long term supply contract. we pay by the tonne but receive up to 600 litres of water from each barge load. All suppliers here have the same water issues. We just do not want to pay top dollar for water instead of diesel fuel. I agree a settling tank will help but this does not stop the fact we are being charged for water instead of fuel. We want to separate it out before the flowmeters so we can claim back to the supplier the discrepancy.

It is remarkable that a quality clause and an agreed method of assessment was not placed in the long-term supply contract clauses!

Is there no scope to reject the consignment because of low quality?

There is a quality clause but it means nothing here. They just stop supply until we pay and our mining operation grinds to a halt. There is only one government supplier of fuel in Indonesia. We are in a very remote location so rejecting one barge load of fuel would be disastrous for us.

I just need an efficient way of getting the water out of the fuel using some type of automatic drain rather than having to rely on human intervention to manually drain it out.

Irrespective of the technicalities, it sounds as though this problem needs to be progressed at Directorate level as well, using appropriate levels of threat and bluff: use the disastrous prospect as a negotiating tool to improve the supply quality. Good luck. _{<unsubscribes>}

Unless you have worked here you won't understand. Directors of companies here mean nothing to government monopoly departments.

We are not in a position to change this. We are however in a position to set up our system to minimise the damage. This is why I posted here looking for some engineering answers as opposed to political wishful thinking.

What about an inline filter with a micron size designed to stop water's surface tension and a bowl under it with an automatic float valve as described by others, dumping the reject into another container.

Install this assemble before the flowmeters and leave the container of reject on the barge ....

Alternately could you insist that you use your own pickup into their tank on the barge? - then you could design your pickup so that it floats and draws Diesel from 2-3 inches below the surface, through a filter, avoiding both floating debris (on the surface) and the water (at the bottom).

This may be a better solution, if you can do it, because then the remainder of the system remains standard and simple.

We have tried fine micron filters but then we suffer from a loss of flow when they block up. They block every 10 minutes. The other issue we have is the barge will charge us demurage costs if we take too long to off load the fuel. Our pumps are capable of 2,000 LPM but are reduced down to 600 LPM when the filters block. I agree the floating suction may be the way to go and use water finding paste to locate the water level so we know where to pump down to. But we still have the problem of the barge leaving it's original port with 400,000 litres on board (which they bill us for regardless of what we pump off) then we pump off 390,000 litres of fuel leaving behind 10,000 litres of water which we have already been charged for as fuel. It is common knowledge that the barge captains sell fuel on the way up the river and replace it with river water. One solution suggested was a settling tank but that still does not stop us having to pay for water instead of fuel. What we really need is a bank of very high capacity separators capable of handling 2,000 LPM which automatically drain the water out when they reach capacity. Finding the separators isn't the problem. Finding an automatic drain system is.

Perhaps a cyclonic separator may be possible because it works on the basis of different densities and does not have filters to clog.

To combat the dishonesty of the barge operators, the only solutions I can see are either,

1. to own your own barge, or
2. to send staff down to accompany the barge from the terminal to your site.

With regard to speed of discharge and clogged filters, perhaps a floating pickup to avoid the water, pumped unfiltered into a holding/settling tank, then pump it at a lower rate through suitable filters into your fuel tanks. Unfortunately this would require you to have double the fuel holding capacity that you need.

I assume they force you to pump it with their built-in pipes. If you could see the fuel level in the tank in some way, say a hatch, then you could watch the suction end of a hose you supply and drop into the tank and stop pumping when it reaches water. Or put a floating stop valve that will sink in fuel but float up on contact with water and close off the inlet.

Electronically, the resistance of fuel and water should be distinct and you could set up a sensor on the inlet of the suction hose and shut off your pumps when it detects water. I assume, again, that the water is not entrained in the fuel but is encountered near or at the end of the fuel transfer?

Or if this is a big enough problem, buy your own tank and have it barged back and forth or even your own barge. Both would require an ability to lock access to their piping and hatches.

Since its crap fuel that you can't use but have to pay for just keep leaving it behind for them to deal with anyway. If you have to pay for what ever they bring you regardless of whether you can use it or not there is little keeping them from just bringing you barges full of water with no fuel at all.

I would guess your contract states you pay for the fuel that the supplier loads not what the barge delivers. Keep track of whats delivered and tell them your contract is for the fuel delivered not a load of water delivered and the barge operator owes them the difference since they are selling it off before you receive it.

If you only take whats good and keep leaving the junk behind the percentage of junk fuel and water mix will eventually reach a high enough level their in their holding tanks it will have to be dealt with by them or those who supply the fuel.

They make the mess they can deal with it other wise if you where dumb enough to sign a contract that you have no negotiating power over I will happily sign one with you as well. I promise to sell you 1 million gallons of fuel pumped and loaded from my end at $2 a gallon every week but what gets to you and how it gets there at the end is your problem not mine. PM me if you want to sign the contract.

I understand that the water separators are having a problem with the large volume of water. Is there any way of using a separate pump, dropping a hose down to the bottom of the barge tanks, and pumping out the separated water until you hit fuel?

If you could do this, your water separators would need much less attention. If you pumped the water into a holding tank or had a meter on the outlet, you would also have an accurate measure of water contamination.

You are an expert on this due to your location.

GA

It occurred to me that you could pump a small percentage back over to them from the bottom of your tank, at the same time as you are filling your tank from theirs at a higher rate of flow.
You will pump a large portion of the settling water back over to them and have mostly fuel in your tank once your tank is full! So Big hose and pump in the top hole pumping into your tank, and a little hose and pump at the bottom pumping back over to them!
If they are going to ne ass*&^% then you need to be sneaky and clever!

Good thinking Deef, but most systems that receive the quantities of fuel described by the OP utilize tanks that are bottom fed to prevent hazardous conditions of falling fuel (which can build up static charges).

Recirculating the fuel will cause it to become entrained (mixed in the fuel).

Drew K

Bob,

I understood that the inflow to the tank was at the bottom to avoid static issues caused by falling fluid.

The pickup point is, I believe, normally placed a little above the bottom because in all fuel storage tanks there is a percentage of water which is periodically drained by reputable operators.......

Could your water separators be triggered by weight? This might take some doing but you could mount the separators on a pressure switch activated pump so that when the weight of the volume hit a certain level, it would trigger the pump....Additionally, if you could have an adjustable volume pump that could match the rate of accumulation of the water for a smoother operation....

Fuel your equipment from a day tank that the fuel is "spun" free for water/contaminates when filling from the big tank the fuel is delivered to, the water you buy is the cost of working there and if you find a way to remove the water before it's metered your suppliers will just add more water till they get the payment they expect.

If possible pump the barge down from the top of the tanks instead of drawing off the bottom. Leave the crappy fuel and water behind.

Install a accurate metering system so you can keep track of exactly how much fuel you pumped and from that you can easily extrapolate the weight of what you took and do not pay for what you didn't take.

No matter who they are crooked dealers do not like solid reliable paperwork trails that point at them. When there is enough people with enough paperwork bureaucrats take notice!

Put a 1000L volume onto your water separator (since you indicate up to 600L of water) and then at the end of pumping you only have that volume to treat.

You might also find a rotating screen filter or similar that self cleans during the pumping operations.

Or, if it is labour cost effective, have a person operating the drain on the water separator, monitoring for water content. (Turn this part into an attended operation and then get a continuous process.)

Alternatively, make the operation SOOOOOOOO tedious that the barge operators get onto your side and complain about the quality of fuel, since while they are tied up at the dock, they aren't getting paid for the next load.

Feel your pain. Same problem. Suspect that it is possible that the barge operators are stealing diesel and then replacing same volume with water. Filtration and separation is the only answer.

I''m trying to remember what we used on submarines before feeding the fuel through a Sharples centrifuge. I think it was a tank separated by a dam that allowed fuel to float over. A sightglass allowed the operator to keep an eye on the level of water in the inlet side of the tank and to drain it before it reached the level of the dam.

As a final trap, a company called VelCon Filters used (haven't heard from them in 20 years) to make a diesel fuel water filter that would stop the fuel flow when its element had trapped the maximum amount of water. The material inside is a paper that swells when it is in contact with water until it looks like a gel.

VelCon used to make most of the fuel filters for aviation refueling systems. May still do.

Water in diesel fuel is a whole lot of fun.

A settling tank is a good idea. Just leave it sit for a day to a week then drain the bottom of the tank until there is fuel contaminating the water that is flowing out.

When you need to use the fuel draw from the top of the tank.

If the problem is salt water contamination there is an extra level of difficulty. This acts as abrasive in the transfer pumps and particularly the fuel injectors.

Heating the fuel and centrifuging it will remove most of the water and some of the salt. Re-centrifuging it and adding clean fresh water to the centrifuge will dissolve some more of the salt.

How much spare tank capacity do you have on site to use as a settling tank?

One of the few advantages to working in remote locations is that often the local labour is cheap enough to make menial task worth doing manually rather than an auto mated process. This puts money into the local community and that helps to engender some good will.

BAB.

You should be careful with heating fuel with entrained and free water will cause the entrained water (cloudy) fuel to appear bright and clear, it also can allow some to pass through the filtration system.

Drew K

Try putting two/three separator units mounted in parallel with a valve arrangement to allow you to switch between units. (make before break switching) As one unit needs draining, switch to the next while you de-water and clean/change filters on the first. The number of units will be determined by the de-watering time. This should allow continuous pumping and be more reliable than an automatic drain.

You are trying to find a technical solution to a legal problem. In my country a simple complaint to the consumer court will land the barge captain in jail and a hefty compensation for fraudulant supply.

Once the fuel and other crap is in your tank you can seperated it with a standpipe recieculation device that mines water or anything heavier than diesel fuel. It can be operated with a pump two conductivity sensors and and a valve. Make the stand pipe like a vertical tank that is higher by about 20ft than the storage tank. pump fuel from the bottom of the tank to a point equal or a little lower than the top of the storage tank into the very large standpipe. Pump and standpipe should have a standpipe velocity of 10 s/ft or lower (my goal is 15 seconds per foot for 15 feet). The part of the stand pipe lower than the tank top can be water storage but it is advisable to set alarms at half that capacity.

The return to the tank is gravity from the near top of the pipe. Make the pump larger than tour fuel usage rate and you can take the fuel from the near top of the standpipe. Water will gather in the bottom segment of the stand pipe and can be amnually of automatically controlled using conductivity as a switch for control or alarm.

If you first one isn't enough add another.

Cheers

These guys offer a separator that handles about 1850 lpm. You may want to parallel 2 for redundancy with a bypass for both to circumvent filtering in the event of unforseen issues.

http://www.diesel-fuels.com/diesel-fuel-tank/high-flow-filtration.php

Good luck!

polyethylene granule can stay on the water surface and sink in the fuel

film with many holes will by better or polyethylene mesh

Remove all filters and do the separation on your side.

What am I missing? If it is such a pain then set up a holding tank and take your time and do what suggestions above recommend from there. This is the only way to eliminate the problems with transferring the fuel.

I can imagine that a "contract" and such isn't worth the paper it's written on were you are. This usually happens when you deal with thieves, there is no comeback. If they would be supplied from a refinery you would have clean fuel.

This is as much as a fuel problem as it is a social problem, not to mention the environmental aspects of it all. Separate pollutants from both and smooth sailing from there. Not funny, I know

Or for a completely different approach, consider that you have a very thick oil film floating on water and use something like:

http://www.oilskim.com/contactform.asp?src=2257

when the tank is full with diesel, water will go to the bottom, on the bottom have a valve open and let the water out!!

leave tjhe filter fitted, get under the car, and open the drain plug on the filter, catch the fluid in a can, allow to drain until clean diesel runs out. tighten drain plug and the give the bulb a few squeezes until hard. If you think you are down on power, the best to change the filter completly, make sure you get a Honda genuine filter.

http://www.bulbeckenvirosolutions.com.au/oil-and-chemical-spill-response-equipment/oil-spill-recovery-skimmer-systems.html

You realise of course that you can be arrested for doing that in public.

Barge of fuel.

Getting under the barge to remove the drain plug does present some problems.

Hi saw you mail recently. We've recently developed an intelligent, filter element less automatic hydrocarbon/water draining system. If you drop me a mail on chow@icon.co.za I'll give you more info. Chris