low temp screw compressors
low temp screw compressors
(OP)
What is the best way to check low temp screw compressors if you suspect they are becoming innefficient? I have a blast freezer with 2 x 90HP economised screw compressors on R507 that are no longer able to pull down the load. All other items such as Elec TX valves etc have been checked.





RE: low temp screw compressors
I'd check suction and discharge pressure and temperature on the screw skid. If those numbers are pretty close to design then the problem is probably in the blast freezers. If the suction/discharge pressure/temperature numbers have a problem then let us know the readings and the expected values and someone here can give you an indication of the problem or where to look to find the data needed for trouble shooting.
David
RE: low temp screw compressors
RE: low temp screw compressors
Screw compressors can tolerate some pretty substantial deviation from the ideal: But to get them highly efficient you want to operate them at 100% load with just enough oil injection to keep them cool and to preclude internal bypassing....Of course, if they are taking liquid refrigerant from time to time, their oil separation, interlobe sealing and so on will suffer a lot.
RE: low temp screw compressors
What type oil is being used and is it suitable for low temp applications?
Have you aded any oil to the compressors?
Ken
Ken
KE5DFR