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Dear friends
we have a screw SAB 163 HM compressor package. we have to replace it's oil cooler. It's an ammonia-oil shell and tube heat-exchanger TYPE OOSI-21142A . I was wondering if anyone here have any information on making a new one. or possibly providing some drawings and more details.
I've attached name plate for both package and oil cooler itself.
Attachment 15474
Attachment 15475
Attachment 15476
Why does it have to be replaced?
Don't have any information of how to make a new one, but if you are removing it, just cut it open and copy the design :)
unable to do the cutting. it is a 2 pass as far as I found out. any more information is highly appreciated.Quote:
Originally Posted by Tycho
l2embo, you didn't answer my question ;)Quote:
Originally Posted by l2embo
Why do you have to replace it?
This a Thermosiphon/thermosyphon oil cooler that has been paired with the compressor unit, that is why I am asking why it is being replaced.
-is it because the compressor unit has been moved, and now the oil cooler is too small for the new application?
-Is there an internal leak in the oil cooler?
-is the oil cooler not cooling the oil?
I don't work much on Sabroe plants, because Johnson Controls has a office/workshop just 3 km down the road :), and the service manager is a friend and former colleague, so I try to not infringe on their plants :)
Anyway, usually, the only problems I have had with the OOSI thermosyphon oil coolers is that oil has collected on the refrigerant side and is reducing the surface area of the tubes that the liquid ammonia can cover and cool down. Many people forget to drain oil from the drain valve that is under the oil cooler (6 on the attached pdf).
Usually oil shouldn't accumulate in the oil cooler, usually, if it is a recurring problem it is because the liquid line to the oil cooler is connected to the receiver in the wrong place. the liquid supply to the oil cooler should be connected as far away from where the liquid from the condenser enters the receiver.
The worst I have seen, was on a plant, where the liquid to the oil cooler was connected to the oil collecting sump on the HP receiver. looking at the receiver, left to right was:
1: liquid from condenser
2: oil sump, and liquid to oil cooler
3: liquid outlet to consumers.
I drained 243 liters of oil from that oil cooler.
Anyways, I talk to much! :)
Here is a link to the information I have about the OOSI thermosyphon oil coolers: https://drive.google.com/drive/folde...DF?usp=sharing
I will PM you the contact information of my friend in Johnson Controls and my Name, so you can name drop ;)
Hi, Tycho
agree with you ....
those oil coolers are quite good, but
as you describe within your post it is quite easy to have
oil cooling problems ... due to all what you describe ...
many times was necessary only to drain oil from ammonia side
and all problems with oil temperature disappear ....
And to be able to help to OP we need some answers ...
otherwise all is like "old wifes tales" ...
Best regards, Josip
The problem is leakage.Quote:
Originally Posted by Tycho
thanks for advices
12embo,
Normally you would just buy a new oil cooler, not make one.
In your country you might have to, I don't know.
But you can a least try to repair, it is possible, by cutting off end caps (first welded connection on each end) exposing tubes in 'tube sheet".
Tube sheet is plate that tubes pass through & welded or expanded in each end of oil cooler.
Pressure test to find leak/s.
If where tubes are welded or expanded into "tube sheet" they can be welded or re-expanded.
In some cases where tube is damaged internally ,tapered pins can be driven into leaking tube both ends of course.
In all cases retest for leaks at vessel design test pressure before welding on
end caps again.
Best to pressure test with oil cooler full of oil, then increase pressure with nitrogen.
If something breaks, it is safer way to do it (hydrostatic test).
http://www.wermac.org/equipment/heatexchanger_part3.html
Ranger,Quote:
Originally Posted by RANGER1
we can not buy from johnson conrtols due the recent problems.
we are on it to make a new one not repair the same one. please kindly provide me with any useful information on that such internal coil volume and available drawings.
Hi, l2embo
Quote:
Originally Posted by l2embo
To make a new one is not that simple without proper material,
machines and technology ... drawings and other things are factory secret
and not easy to obtain ... maybe someone on RE forums can help somehow..
Much better, I believe, to buy it from China supplier of Sabroe parts ...
must be quite simple and fast ...
I was working with China company in Shazand Petrochemical Plant
and they can provide almost everything.
Repair, as Ranger1 suggest, is not bad advice ... it is the cheapest solution
and I know you have good welding specialist there ...
if you prepare all in a good way you need max 2-3 days to do that ...
Best regards, Josip
12embo,Quote:
Originally Posted by l2embo
You cannot copy this oil cooler I believe.
Internally tubes have special extra fins or surface area to make oil cooler very efficient & compact.
A new oil cooler can be made, but will be possibly be bigger in length &/or diameter.
Oil coolers are made to order for specific oil flows & conditions & capacities.
I would definitely try to repair if in your situation.
Alternatively can you give exact information on
- refrigerant type
- suction & discharge design pressures
- compressor name plate
- speed of compressor.
In a lot of cases this information can be with documents supplied when compressor was new.
If capacity of oil cooler can be obtained, do you have access to heat exchanger company that can make it to a specification.
A plate heat exchanger could be another option if one can be imported.
Last, but not best option, convert to liquid injection cooling.
Hi
You can replace it with another oil cooler with other brands
Or you could find 2end hand
Thanks for the info!