Propane carryover into twin screw compressor
Propane carryover into twin screw compressor
(OP)
We are planning a revamp of a gas plant and when checking the refrigeration system velocities in compressor suction scrubber are exceeded, then liquid carryover may be expected.
What could be the consequences of excessive propane carryover to the compressor?
Thanks,
What could be the consequences of excessive propane carryover to the compressor?
Thanks,





RE: Propane carryover into twin screw compressor
Since the oil must be compatible with gaseous propane then the liquid propane (which is a terrible lubricant) will displace some of the screw oil and if this is a long-term thing then you risk some serious lubrication problems. A splash of liquid every so often is no big deal. There is a good chance that the oil is warm enough to flash the propane anyway, but that is not guaranteed.
How fast is the propane going through the scrubber anyway (and at what pressure)?
David
RE: Propane carryover into twin screw compressor
As you stated, it is an oil-flooded screw. Maximum expected velocity in the scrubber is 4.9 ft/s, that is a K factor of 0.45 at suction P&T (30 psia & -11°F).
The scrubber has a two layer demister, the first one has a density of 5 lb/ft3 while the upper demister has a density of 12 lb/ft3. K factors for these demisters area 0.385 and 0.324 according to ACS Mistxpert.
RE: Propane carryover into twin screw compressor
David
RE: Propane carryover into twin screw compressor
Thank you very much for your answers. I think I´ll follow your advice.
RE: Propane carryover into twin screw compressor
RE: Propane carryover into twin screw compressor