Characterization of oil injected screw compressors and air/oil separators at realistic operating pressures

Abstract

An experimental setup to determine the particle size distribution (PSD) of a pressurized oil aerosol (p < 10 barÞ was validated. The combination of optical particle counter (OPC) and scanning mobility particle sizer (SMPS) measurements allowed for the evaluation of PSDs in the size range 40 nm < d p < 3 lm. The raw gas oil emissions of two oil injected screw compressors were determined and compared to a test aerosol generated by a Laskin Nozzle aerosol generator. While the screw compressors showed considerable differences in gravimetric oil load, the normalized PSDs of both compressors were found to be similar, exhibiting main mass fractions in the particle size range between 0.1 and 2 mm. The influence of operating conditions on the fractional separation efficiency of fibrous oil mist filters was also studied in this work using a conventional air/oil separator filter. An increase of either pressure, temperature, filter face velocity or oil loading rate led to a deterioration of separation efficiency emphasizing the need for filter testing under realistic operating conditions.

Impact of Built‐in Helical Fins on the Performance of Oil‐Gas Cyclone Separators

“…For sealing, lubrication, and cooling, the lubricating oil is injected into the compressor cylinder during operation [4,5]. Oil and gas separation must be performed at the compressor discharge to ensure gas purity, system efficiency, and compressor life [6]. Effective primary separation of oil and gas is of utmost importance.…”

Numerical Investigation of Oil Gas Separation with the Use of VOF CFD

“…Figure 1 illustrates a complex screw compressor with oil injection equipment, developed by the NRDI for Gas Turbines COMOTI. The use of such a system implies oil-air separation, which can be done using a separator vessel [5] that is provided with filters capable to retain the oil particle and separate them from the pressurized air [6]. A schematic presentation of a classic two-phase separator can be observed in Figure 2.…”