Compressor crank case venting arrangement for eliminating lube oil carryover

Claim 1

In a reciprocating gas compressor comprising: a compressor housing including a crank case for housing the compressor crank shaft and having at least one piston supported by said crank shaft and reciprocating within a fixed cylinder and defining with said cylinder a working chamber, a vertical housing end wall defining a crank case vent passage separate from and to the side of said crank case, an intake manifold overlying said compressor housing and being ported to said working chamber, a coalescent separator vertically mounted within said crank case vent passage and spaced from said end wall to separate said crank case vent passage into a first chamber underlying said intake manifold and a second chamber, a first vertical opening within said first chamber leading directly from said crank case vent passage first chamber into said intake manifold, and a second opening within said housing second chamber for normally introducing the gas to be compressed to said second chamber for passage through said coalescent separator to remove oil carried thereby, a first opening within the bottom of said end wall and carrying a check valve to permit oil flow from said First chamber into said crank case, and a second opening within said end wall above said check valve opening for permitting oil-air mist within said crank case to vent from said crank case into said crank case vent passage first chamber, the improvement comprising: means for blocking said first opening within said first chamber, means for directing the intake gas to said compressor directly to said intake manifold, bypassing said first and second chambers, and means for fluid coupling said second housing opening directly to said intake manifold, whereby; the oil-air mist within the crank case entering said first chamber from said crank case, passes through said coalescent separator to remove the oil therefrom to permit venting of the crank case gas resulting from blow-by to the intake manifold, and returns the removed oil back to the crank case through said check valve to eliminate compressor lube oil carryover.