Seperator Problem

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alestevardiya
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Seperator Problem

Postby alestevardiya » Fri Jun 12, 2015 1:09 pm

Hello friends... We have Alfa LAVAL PA 650 separator to seperate Lub Oil... When I join the vessel They reported me not to work because of the leaking problem! I changed all seals with intermediate Service kit... Whenever I star up the seperator first leaking water continiously after 1 min coming oil very much! I checked water quantity OK... I checked gravity disc OK... I degrease back pressure... After degreasing back pressure I Realise that leaking water was sealing water! I add sealing water every minute for 1 second only and 9 min only water comes not oil leaking! Something broke down my inside pressure! So first it comes Sealing water and then oil! What do you thing about this problem would you please share your opinion???

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Big Pete
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Re: Seperator Problem

Postby Big Pete » Sat Jun 13, 2015 2:17 am

First thing with separators, have you checked that the bowl is turning at the correct RPM?

Possible causes are that the clutch/ drive belt is slipping or somebody has mistakenly ordered and fitted the wrong ratio of gears or pulleys, also it is possible that a motor of the wrong speed has been fitted at some time.
There are always 2 sets in the spare parts list, one for 50 Hz electrical supply and one for 60 Hz. The 60 Hz motor will run 20% faster than the 50 Hz motor, and to keep the Purifier bowl speed the same the Velocity Ratio for the drive from a 60Hz Motor will have to be 20% less.

If you are running on a 50 Hz supply and use parts from a 60Hz drive chain, the purifier will run too slowly to work, if you have a 60Hz supply and use a drive chain designed for 50Hz the bowl will over speed by 20% and will be liable to explode due to excessive centrifugal force.

Second question, did you use every single seal and "O" ring in the intermediate kit? The only one left over should be the one for operating as a Clarifier bowl, rather than as a purifier.

Third question, what temperature are you purifying the oil at? It should be 95 Celsius for a 4 stroke engine or 90 C for a slow speed 2 stroke. (98 C for HFO). The oil should be recirculated, through the heater, until it reaches this temperature, before admitting it to the purifier.
(Also, when shutting down the purifier the oil should be recirculated through the heater until it goes cold, to prevent the oil overheating and carbonising in the heater.)

Fourth question have you checked that all the water supply filters are clean and flow is unrestricted and that the operating water pressure is correct according to the makers manual, are any orifices fitted "Original Equipment Maker's parts" and the correct flow rate? Many modern separators have precisely controlled water pressure and precision flow control orifices to deliver a precise amount of water in a certain time, so that all the quantities of water delivered can be controlled by a computerised timing system.
Because the bowl sealing water tends to evaporate at the temperatures Lubricating Oil and HFO are purified at, there is usually a timer that will automatically add a small quantity of "top up" sealing water at short intervals, again see your maker's Manual for full details.

Fifth question have you thoroughly cleaned all the water spaces including the drilled passages through the bowl?

Sixth question have you checked the oil flow rate is that recommended by the Makers Manual? Too high a flow rate can cause loss of seal and also means that less dirt is removed from the oil, because the "Dwell Time" in the bowl is less.

If all the mechanical points above are correct, then start to compare the programming of the values in the operating system against the values in the makers Manual, in case some idiot has changed these.

Please let us know how you get on, and good luck.

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

alestevardiya
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Re: Seperator Problem

Postby alestevardiya » Sat Jun 13, 2015 5:50 am

Thanks for detailed Reply yes I changed Every sing Seal/o ring ... Yes I checked water one by one.... Yes I checked time etc all parameter... Speed is not seen at this type... I am thinking to change V belt and brakes....
And I thought to use clarifier but even I dont have clarifier disc and parameter couldnt change from pruf to clar.
Finally I Will look speed any more and Will see what happen???

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Big Pete
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Re: Seperator Problem

Postby Big Pete » Sun Jun 14, 2015 12:48 am

Good, it sounds as if you are making progress eliminating the possible causes.
When changing the belt drive remember to follow the makers instructions precisely. I am not familiar with this model but the belt driven Lavals I have sailed with used the following procedure to change the drive belt.
1) Remove electric motor, clean and lubricate base of the Motor and the surface it slides on while tensioning the belt, using Molybdenum Disulphide, extreme pressure lubricant.
2) Fit the belt.
3) Tension the belt using the special jacking bolt on top of the purifier body until the spring inside it is fully compressed and the drive pin no longer engages in the slot, and the bolt turns freely without increasing the tension. The spring tension is a constant, subtracting the sliding friction of the motor from that leaves an amount equal to the belt tension, ensuring consistent belt tension whenever the belts are changed. It is important that the sliding surfaces are properly cleaned and lubricated or the belt tension will be too low. If someone has painted over the jacking mechanism that should be cleaned and lubricated as well. After a few hours running the belt will have stretched slightly and the procedure should be repeated.
If the belt is over tightened, that will shorten the life of the belt and the bearings, if it is too loose, it will tend to slip and overheat.
For maximum life the belt has to be adjusted correctly, very simple once you have done it, but difficult to fully describe.

I am not trying to be patronising here, I joined one ship where the Engineers said they were so good that they didn't need to read the instruction books, but were complaining that the purifier drive belts only lasted a few days! I found they were putting them on with a crow bar to stretch them over the pulleys!!

From my Desk, which is always a bad place to make suggestions from, I think it most likely that either the purifier is running too slowly, or that one of the seals is leaking, but you are the man on the spot and the only person who knows the full story of what is happening.
Good Luck,

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

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Merlyn
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Re: Seperator Problem

Postby Merlyn » Sun Jun 14, 2015 11:39 pm

I once sailed with a second whose party piece was to remove and refit these belts with a small flat crowbar whilst still running. Nifty and of course instantanously done. He used to show off doing it even if the belt didn't need changing. Last time I saw him he still had all his fingers on board.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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JollyJack
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Re: Seperator Problem

Postby JollyJack » Tue Jun 16, 2015 6:12 pm

Were they still attached to his hands?
Discourage incest, ban country "music".

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Merlyn
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Re: Seperator Problem

Postby Merlyn » Wed Jun 17, 2015 2:21 am

You need quick reactions and an firm grip on the small crowbar to do this and yes they were still attached when I saw him last. No good doing it the morning after the night before syndrome here. No shaky hands here, if the bar takes charge no one is safe even 40 foot away. Crazy like riding the shaft.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

alestevardiya
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Re: Seperator Problem

Postby alestevardiya » Thu Jun 18, 2015 11:48 pm

Hi all... I never do anything without reading instruction book ... Dont wory :)
I changed friction elements and v belt... Nothing change :(
First water coming after water fnished oil leaking very amount of!

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D Winsor
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Re: Seperator Problem

Postby D Winsor » Fri Jun 19, 2015 3:14 am

Problems like this can be very frustrating It looks like you are having difficulty maintaining a proper water seal in the bowel
Have you checked the following?
The water flow from the sealing water header tank to the purifier. It has been my experience that even a small disruption in the water supply can cause many problems especially if you have issues with blocked lines or a common header tank for multiple purifiers as a leak in another purifier in the system can cause major problems the other purifiers on the system.
The Teflon ring in the sliding bowel. It has been my experience that sometimes a ring that looks OK visually may leak, also a minor nick or burr in the top cover can also cause leakage problems at that Teflon seal.
Oil flow and temperature Regulators. It is possible that the oil is being supplied to the purifier is too hot or at too high a flow rate. Try manually controlling the flow to the purifier to see if the same thing happens.
The Taper at the top of the spindle shaft and in the bowel. It is possible the shaft taper may be worn or damaged and there is not sufficient contact between the bowel and the spindle to prevent the bowel from slipping at high speeds. It may also be possible that the lock washer and or nut may be damaged preventing the correct amount of torque to be applied to create a correct interference between the shaft and the bowel
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

alestevardiya
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Re: Seperator Problem

Postby alestevardiya » Sat Jun 20, 2015 12:51 am

Dear D Winsor as I said before first I checked Waters :) there is no header tank water comes from hydrophore I checked water quantity by second... Also I said before I changed Every single o-ring Teflon ring etc in the insp. Kit! If it is leaking from teflon it didnt cut whenever I add sealing water Every minute.... I checked flow and temperature as you can see Above message :D whatever I will request Service Engineer .... :(

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Big Pete
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Re: Seperator Problem

Postby Big Pete » Mon Jun 22, 2015 4:12 am

Well done for admitting defeat and calling in a service engineer. Too many people do what your predecessor did and just keep quiet and leave it for someone else to fix. Sorry that we weren't able to help you fix the problem. Please let us know what the service engineer finds.

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

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D Winsor
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Re: Seperator Problem

Postby D Winsor » Mon Jun 22, 2015 6:10 am

I forgot to mention in my previous post to ask if you changed the springs under the sliding bowel?
I remember a similar problem with a Heavy Fuel Oil Purifier and we changed the springs, fixing the problem, after nothing else seemed to work. It seems the sliding bowel depends on these springs to keep the bowel closed and become weakened over time allowing the sliding bowel to open when the bowel is pressurized with the feed oil.
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

Atlantic
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Re: Seperator Problem

Postby Atlantic » Tue Jun 23, 2015 4:39 am

Hi,

Did you have it apart again since you changed the O-rings? It's easy to damage the rectangular ring that's on the lower stainless bowl, the one under the discs, during assemble I did this myself last month. And it gave me a similar problem. How are the bearings check the maintence history if they have been changed, you can check them for play. Also some models have the water going in through the spindle it can clog up. Did you change the nozzles in the big bowl? Check that the Teflon plugs and ring are fitted right and not damaged.

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Merlyn
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Re: Seperator Problem

Postby Merlyn » Tue Jun 23, 2015 5:07 am

My old outfit had a saying for situations like these. If you can't fix it fix it so no other f---er can fix it. The obvious idea behind this was to ensure you always looked like the expert and were never caught out as we all know sometimes it the simple things like a nick in an O ring etc which someone else might go straight to and you would never live it down.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

alestevardiya
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Re: Seperator Problem

Postby alestevardiya » Thu Jun 25, 2015 2:15 pm

Hi again.... Atlantis I checked orifis which closing water comes! And also checked the bearings and changed the Teflon ring and plugs! After I changed all kit and also friction elements and degreasing Pt4 outlet pressure I changed grativy disc again with Smaller one! But again first coming sealing water and then oil! :( It is not closing problem... It is leaking problem from upside... Whenever I add Sealing water no any oil leak problem! Anyway I will let you inform when I know :)


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