oil foaming&capacity regulation

[MO3TAZ]

hi all,
\i got sabroe 163 amonia compressor ,seeing the sight glass of oil seperator i see foams on oil what might be the cause&how i cure it.
another problem is the capacity pointer it regulates madely upper and lower by it self
thanks in advance

[MO3TAZ]

???????????

[RANGER1]

MO3TAZ,
Maybe liquid ammonia entering suction line.
CAn you advise us on oil & discharge temperature.
Also what type of oil cooling water, thermosyphon or liquid injection.

Slide valve continually loading or unloading check it is high motor amps or high discharge pressure forcing it to unload.
If solenoid a not being energized either leaking loader solenoid or
unload piston damaged or scored unload cylinder.

[PaulZ]

Hi MO3TAZ
To add to Rangers questions regarding the foaming oil.
Is there only one compressor?
Is the foam there all the time?
regarding the loading / unloading problem.
How long has it been since the compressor was overhauled?
Regards
Paul

[MO3TAZ]

mo3taz,
maybe liquid ammonia entering suction line.
Can you advise us on oil & discharge temperature.
Also what type of oil cooling water, thermosyphon or liquid injection.

Slide valve continually loading or unloading check it is high motor amps or high discharge pressure forcing it to unload.
If solenoid a not being energized either leaking loader solenoid or
unload piston damaged or scored unload cylinder.

no liquid in suction line but head is cooled by liquid injection & oil is cooled by liquid amonia from receiver
discharge is normally 10-11 bar &oil temp from 54 to 68 degree
motor amper is normal
compressor loads and unloads normally by indicator is not stable

[MO3TAZ]

hi mo3taz
to add to rangers questions regarding the foaming oil.
Is there only one compressor?
Is the foam there all the time?
Regarding the loading / unloading problem.
How long has it been since the compressor was overhauled?
Regards
paul

we got 3 compressors working in parallel
oil foaming occurs all the time only on this compressor
it was overhaules 2 years ago

[RANGER1]

no liquid in suction line but head is cooled by liquid injection & oil is cooled by liquid amonia from receiver
discharge is normally 10-11 bar &oil temp from 54 to 68 degree
motor amper is normal
compressor loads and unloads normally by indicator is not stable

Can an you explain more on liquid injection, as you state you have thermosyphon oil cooling.

Sometimes if oil cooler is to small or not working to design, people add liquid injection, so wonder if this is the case?

Is oil & discharge temperature the same, can you also give us this temperature!

There are usually 2 solenoids to load & unload compressor.
There is also needle valves that control speed of loading/unloading. if you isolate them (taking note of how many turns open) then see if load position stay stable. If it does solenoids may be leaking, if it still moves by itself then unload cylinder may be scored or piston seal is damaged, or both.

[RANGER1]

MO3YAZ, Also 1 solenoid is normally open the other normally closed for capacity control.
Solenoid, I think on left when looking at end of machine, should be energized & the one on right de-energized for no loading/unloading to occur.
Normally open solenoid has groove on armature tube under solenoid coil, this has to be energized to close.
If coil is defective, it will unload all the time, just need to check to eliminate it.