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engrp
12-06-2012, 08:33 AM
good day, fellow members. can a restricted oil separator cause a high discharge in a compressor ? is there a procedure to clean the inside of the oil separator, short of opening it up ? can i use nitrogen to flush it ? the oil sep is mounted to a sabroe smc 112L nh3 compressor.
i am just soliciting your advise, if there is a possibility that there is any other external factor contributing to the high discharge, short of opening up the compressor. restricted condenser tubes are already out of the factors. thank you

Rob White
12-06-2012, 08:46 AM
good day, fellow members. can a restricted oil separator cause a high discharge in a compressor ? is there a procedure to clean the inside of the oil separator, short of opening it up ? can i use nitrogen to flush it ? the oil sep is mounted to a sabroe smc 112L nh3 compressor.
i am just soliciting your advise, if there is a possibility that there is any other external factor contributing to the high discharge, short of opening up the compressor. restricted condenser tubes are already out of the factors. thank you

High discharge could be caused by many, many differant things.
You need to cheack the obvious and the easy first.

Is the condenser blocked, choked or restricted?

Measure the temperature of the liquid coming out of the condenser and
compare it to the condensing temperature. It should be lower.
If the liquid line is not lower in temp than the condensing temp then
the liquid is not condensing and it is a condenser issue.

In answer to your question about oil seperators, yes they can restrict
and no they are hard to check without removing and stripping down.

If you are thinking of nitrogen flushing it why dont you fit schrader valves
in the discharge before and after the oil sep and before and after the condenser?
You will be able to see where any restriction is then.

Regards

Rob

.

D.D.KORANNE
12-06-2012, 10:28 AM
1) usually the oil separators are hermetically sealed hence cleaning is difficult. Although you can try out by reverse flow low pressure nitrogen that can clean only dust particles that may be sticking on the baffle plate in it.first remove it from system .

2) moreover it also depends upon the type of oil separator ;whether spiral type / baffle plate type while considering effectiveness of cleaning.

3) yes blocking of gas path in discharge line can raise the high side pressure . Measure dis pressure on compressor outlet & outlet of oil separator ............if restriction in oil separator , outlet pr of oil separator could be lower due to restriction ............and comp high side pressure could rise.

Sandro Baptista
12-06-2012, 12:12 PM
Also high superheat can contribute to the high discharge temperature.

What are the operating condition of the compressor? Please send us the pressure measurements at inlet/outlet compressor and also the suction and discharge temperature. Register that values at 33% and 100% compressor capacity.

About the oil separator cleaning there are specials products to dilute the debris on the mesh of the oil separators.

RANGER1
13-06-2012, 10:29 AM
Iwould first check where the resriction might be, if there is one.
Discharge stop on compressor & discharge non return valve after oil seperator would be next.

Do you have a reason to believe that oil seperator could be choked up?

Josip
13-06-2012, 02:27 PM
Hi, engrp :)



good day, fellow members. can a restricted oil separator cause a high discharge in a compressor ? is there a procedure to clean the inside of the oil separator, short of opening it up ? can i use nitrogen to flush it ? the oil sep is mounted to a sabroe smc 112L nh3 compressor.
i am just soliciting your advise, if there is a possibility that there is any other external factor contributing to the high discharge, short of opening up the compressor. restricted condenser tubes are already out of the factors. thank you

From Sabroe manual....

"Sabroe oil separator consist of stainless steel wire mesh which, as a rule, needs no cleaning, nor does it get worn. Consequently, the filters cannot be removed from the oil separator."


Maybe is there some problem with oil return back to crankshaft case and oil separator is clogged with oil, but you did not mention any problem with oil level within compressor crankcase.

Do you have oil return controlled via solenoid valve or float control valve ... check that line but first close discharge and suction valve on compressor and evacuate compressor to atmospheric pressure ...


To me all sounds like you have some air within your system ... try to purge your condenser/s and receiver/s. If you can to store all ammonia into evaporators and suction separator you can use a vacuum pump to evacuate condensers snd receiver...


Best regards, Josip :)

engrp
15-06-2012, 02:45 PM
thanks to all your suggestions . it seems a blocked oil sep is very remote, based from your comments. thanks again. will further check the system.

piewie
16-06-2012, 04:04 PM
Are you talking high discharge pressure or high discharge temperature? I would check on the obvious things first. Is the oil seperator full of oil? Have you checked the operation of the oil return system? Is the check valve operational? How are you measuring the pressure or the temperature? If I remember back the 112L is a long stroke compressor which was prone like the E series to running at high discharge temperatures. The details of the plant are a bit vague is it a single compressor plant? Is it a single stage setup or a booster plant compressor? With a few more bits of details I think we should be able to help you along the correct path.

piewie
16-06-2012, 04:06 PM
Hello Rob

I don't think it is a good idea to use schrader valves with an ammonia compressor. Brass and NH3 are not compatible.

RANGER1
16-06-2012, 10:21 PM
Hello Rob

I don't think it is a good idea to use schrader valves with an ammonia compressor. Brass and NH3 are not compatible.

It may help relieve the excess pressure though!

Josip
17-06-2012, 01:17 PM
It may help relieve the excess pressure though! :D



Best regards, Josip :)

Rob White
18-06-2012, 03:58 PM
Hello Rob

I don't think it is a good idea to use schrader valves with an ammonia compressor. Brass and NH3 are not compatible.


Good point.......... I missed that bit :eek:

Rob

.

Rob White
18-06-2012, 04:01 PM
Hello Rob

I don't think it is a good idea to use schrader valves with an ammonia compressor. Brass and NH3 are not compatible.

I'm glad you noticed my diliberate mistake........ :p

Regards

Rob

.

Josip
03-09-2012, 07:33 PM
Hi, engrp :)


good day, fellow members. can a restricted oil separator cause a high discharge in a compressor ? is there a procedure to clean the inside of the oil separator, short of opening it up ? can i use nitrogen to flush it ? the oil sep is mounted to a sabroe smc 112L nh3 compressor.
i am just soliciting your advise, if there is a possibility that there is any other external factor contributing to the high discharge, short of opening up the compressor. restricted condenser tubes are already out of the factors. thank you

It will be very nice, if you tell us what was wrong at the end of this case.;) Of course if you know.

We were right, wrong or somewhere in the middle of the road!?!

Thanks!

Best regards, Josip :)

engrp
03-09-2012, 10:07 PM
sorry josip, we have not dismantled the sabroe yet. we are currently overhauling the grasso rc 612, but will be opening up the sabroe a few weeks after the rc612 is on line. before i open up the sabroe, i will be doing some of the advise given in ths thread and will post it as we perform the tasks. as always, i am greatful to all of you for taking the time to give tips and comments , sorry if i have been remiss in updating you and fellow members of the results of your comments and advise.

Josip
03-09-2012, 10:23 PM
Hi, engrp :)


sorry josip, we have not dismantled the sabroe yet. we are currently overhauling the grasso rc 612, but will be opening up the sabroe a few weeks after the rc612 is on line. before i open up the sabroe, i will be doing some of the advise given in ths thread and will post it as we perform the tasks. as always, i am greatful to all of you for taking the time to give tips and comments , sorry if i have been remiss in updating you and fellow members of the results of your comments and advise.

no problem, take your time .... I was just curious ...;)

Best regards, Josip :)

RANGER1
04-09-2012, 11:13 AM
I have found the product "brake cleaner " extremely good for cleaning.
Its not cheap in a 20 litre drum, but it does the job.
You continually circulate it & it loostens up & breaks bown carbon etc.
"brake cleaner" believe it or not is usually used for cleaning the brakes on your car.
It will also evaporate, similar to the old R11.
Don't catch on fire using it though!

engrp
04-09-2012, 02:37 PM
yes, ranger1 , i have heard of this chemical. but is very expensive here. thanks for the suggestion.