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bernard
30-08-2006, 09:49 PM
Hi

I fitted my guages onto the suction of the sub-cooler on a Moducell LT screw pack.The suction pressure was 60 psi,there was no E.P.R. fitted,the sub-cooler suction line went straight into the compressor.The compressor suction was 6 psi.I realise there must be something inside the screw,can someone please explain this thanks.

Regards Bernard:)

dakesojo
30-08-2006, 09:59 PM
the 6psig suction pressure is that from your gauges or the plant control gauges as they may need recalibrating , when i worked on compound screw pack always a problem

US Iceman
31-08-2006, 12:24 AM
Hi bernard,

Let me see if I have this right...

The suction line on the subcooler goes to a side port on the screw compressor. There is no EPR on the subcooler suction line.

The side port pressure will always be higher than the suction pressure when the compressor is fully loaded.

Think of it like this: When the rotors are turning they are compressing gas from suction pressure to discharge pressure.

The location of the side port is between these two pressures (suction & discharge), therefore it would follow the pressure in the side port would be somewhat higher than the compressor suciton and lower than discharge pressure.

Whatever this pressure is, would be your subcooler suction line pressure (not counting pressure losses in the suction line of course).

If the compressor suction pressure increases, the side port pressure also increases.

bernard
31-08-2006, 01:29 PM
Hi


Makes sense now iceman,thanks

Regards Bernard:) :) :)