Plate cooler

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MarineNewfie
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Plate cooler

Postby MarineNewfie » Thu Jul 30, 2015 5:18 pm

Just wondering if anyone has ever added extra plates to have greater cooling? Currently sailing the Great Lakes area and having cooling troubles. 2 aux generators and main engine are cooled by same common system causing some issues when running engine and generators at the same time. Before ordering some new plates I just wanted to know if anyone has had this issue or have done this and if it is worth a try. Coolers have been opened and cleaned.
Thanks

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Merlyn
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Re: Plate cooler

Postby Merlyn » Fri Jul 31, 2015 5:35 am

H2So4 pumped hydraulically thro' the system to get at those 90 degree elbow ends? Flow meter check?
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MarineNewfie
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Re: Plate cooler

Postby MarineNewfie » Fri Jul 31, 2015 7:19 am

Yeah. Flow is good. Pressures good. The ship was designed for deep sea and is now sailing inland waters. Wasn't sure if anyone has had the experience of adding plates and if this made a difference.

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Merlyn
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Re: Plate cooler

Postby Merlyn » Fri Jul 31, 2015 12:10 pm

Can't say as I have encountered this, if nothing has changed then surely there must be an inherent fault developed? Do the three engines rise in temps proportionally or is the main higher? Calculations ref increased surface areas and heat dissapation ought to be considered ref adding new plates methinks. We use a portable digital infrared Red Ray gun temp measuring tool for this type of situation, shine the two rays emitted onto the surface to be measured , move nearer or away to line up the two red dots shown and in the digital window is the temp of whatever you are shining it at. You can do it in C or F and store readings etc. good for either side of a Stat housing to see if he is fully open at the temp stamped on his body without taking the Stat housing off. An instant and accurate test. You can go all over the engine to measure heat exchangers in and out, ditto oil coolers, turbos, pto pumps, sea suctions / discharges , oil pipes etc etc, the list is endless. Good bit of kit costing around forty pounds over here. Also we use it a lot as some engine sensors display different resistance readings at different temps and to test them fully you need a cold start right thro' to max temp to be sure the particular sensor is operating correctly through the the total heat range and then compare all readings with manufacturers figures. You can also shine it on your workmates various body parts to ensure no localised overheating occurs ref overexcitment of whatever or if any imbalances are present, ie left v right?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

MarineNewfie
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Re: Plate cooler

Postby MarineNewfie » Fri Jul 31, 2015 5:15 pm

Thanks for the reply. Nothing has changed besides operating with seawater temps at 17-18 degrees Celsius to operating in fresh water with higher temps. Poor design for this area. Just was thinking with the addition of extra plates we would get more cooling.

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JollyJack
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Re: Plate cooler

Postby JollyJack » Fri Jul 31, 2015 6:14 pm

After a visit to the lakes. we always had problems with zebra mussels, choked the sea water side of the coolers. The only fix is scrape the little buggers off!
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Merlyn
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Re: Plate cooler

Postby Merlyn » Sat Aug 01, 2015 3:01 am

JJ, bet you loved eating all those mussels, they sell for mega bucks over here in the restaurants and you got them all FOC. Bet they tasted better FOC. Concerning the keel coolers looks like the old slide rule/ calculator needs digging out then. Dust off all those long forgotten books you thought you would never see again and back to PV/T = C equivilant for calculating surface areas and heat dissapation losses required for new plate set/s in certain sea temps. Sounds interesting stuff, a little different perhaps but don't forget to allow for a deep sea return re temp differences? Don't want any lube oil probs re running too cold maybe. Sounds expensive, slipping, design and supply and fit, downtime etc. Let us know how you got on, sounds interesting stuff. Someone will have to draw out here all right. Point of interest I remember things like steaming down the Bay of Biscay watching T's and P's down below when relatively close to land and seeing sudden coolant temp changes. They dropped because the outside sea temp reduced by a few degrees owing to mountains melting snows etc, down rivers and exhausting to sea via the estuary and into your path. Once past temp reverted to normal. Noticed this doesn't apply in the summer months presumably owing to no melting of the snow/ ice etc.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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JK
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Re: Plate cooler

Postby JK » Sat Aug 01, 2015 3:08 am

We installed strainers in our coolers. I should see if I can get a photo of the end plate to show the location. It was amazing the difference it made in cooler operation.
If you got 2 coolers, put 2 in operation to see if there is difference.
I'd get in touch with the plate supplier and get them to grind some numbers for you for the number of plates you will require and the new torquing requirements for the plate stack. They'd probably do it in breathless anticipation of an order.

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JK
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Re: Plate cooler

Postby JK » Sat Aug 01, 2015 3:11 am

The thermostatic valve would take care of too many plates installed.

The other thing we had to do was installed a grid plate under the cooler to stop the mussels and crap going into the bilge when the strainer was pulled. The mussels played havoc on the bilge strainers, never mind the stink of what lodged between floors.

Vegman
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Re: Plate cooler

Postby Vegman » Wed Aug 12, 2015 3:05 am

Yes have done it on Ulstein built PSV with similar cooling set up as you described , vessel had been operating North sea for many years.
It went to a contract in India before it came my way and apparently they had had some problems there because they ordered extra plates but never got around to installing them.
Vessel came to Queensland Australia where I worked on it- working shallow water on coal wharf construction- we always used to run with both plate coolers on but even then cooling was always marginal and for some reason got gradually got worse- LT temp would go up and first problem was that AC would go out on high pressure.
Finally bit the bullet and added about 20 % extra on each cooler- Must be very careful to get plates in correct order and alignment.
It definitely made a difference.-
But i suspect there may have been an underlying problem that we never discovered such as clogging of sea intake grids or sea chests.- vessel later redelivered to Europe.
Cooler was "sondex " brand , very similar to Alfa Laval.

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JK
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Re: Plate cooler

Postby JK » Wed Aug 12, 2015 7:39 am

I had one ship that on more then one occasion over the years ended up on the dock because SW lines were plugged solid with mussels. The lines had to be removed and reamed out.

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JollyJack
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Re: Plate cooler

Postby JollyJack » Wed Aug 12, 2015 11:02 am

I joined a ship in Newcastle, NSW. which had been laid up for some 6 months. The mussels were nearly a foot long and so thick in the thruster tunnel, the prop wouldn't turn! I had divers clean them out and survey the underwater hull. Funnily enough, coverage was mostly fine seaweed, athough there were quite a few big mussels and barnacles as big as tennis balls!
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spanner
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Re: Plate cooler

Postby spanner » Wed Aug 12, 2015 5:43 pm

I was involved in the addition of plates on an Alfa-Laval unit. The shell and tube oil cooler was condemned at refit, lead time for a replacement was too long and a plate cooler was on hand close by. It was configured for a 16 cylinder and we had a 20 cylinder. The powers that were said, lets try it and see how it goes. Sure enough the oil got too hot under full load. Some time later (years) 25% more plates were added. The manufacturer recommended the right number of plates and gave us the new dimension between the two end plates to compress the new stack to. It's been some time but I don't remember it being a big deal. So long as the frame the plates are in allow for the sliding plate to move out to accommodate more plates. There may be an issue if you have pipes attached to both end plates. This is the case with a Tranter plate exchanger I work with using s/w to cool two separate circuits; jacket water and the aftercoolers. From what I've seen 4 years is about max before a plate exchanger should be taken apart and cleaned, if a problem doesn't appear sooner. The seals on an oil cooler will be brittle. If it is using s/w for cooling, no matter how good the s/w strainers are some crap will get through to plug the cooler as the space between the plates is narrow. A pressure gauge on the s/w inlet to the cooler is helpful. Pressure test it afterwards, for the time and trouble it's cheap insurance. Also required by the class guys if it's due for inspection.

Atlantic
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Re: Plate cooler

Postby Atlantic » Thu Aug 13, 2015 8:01 am

I would contact the manufacture of the cooler, you can add to many plates and mess with the flow rates and actually lose cooling capacety.

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Big Pete
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Re: Plate cooler

Postby Big Pete » Mon Aug 17, 2015 2:46 am

As the previous poste suggests if you add too many plates you can increase the pressure drop across the cooler and reduce the flow in both the Sea Water and Fresh Water circuits and actually make the cooling worse.
However, I would suggest that you would have to add a large number of plates, or over tighten them (closing in the water channels between them) to do this.

Another thing to watch for is that heat exchangers are generally designed for about a 10 Degree Celsius temperature change across the cooler, for both the Fresh and Salt water.

Adding too many plates will raise the temperature of the sea Water leaving the cooler and possibly raise it to the point where scale deposits start to form on the plates and in the overboard discharge pipe, also hot sea Water becomes very corrosive.

BP
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