Oil management system for screw compressor utilized in refrigeration system

In a refrigeration system of the type having a screw compressor with an inlet for pressurizing and circulating refrigerant through the system and an evaporator having a shell enclosing a chamber for allowing phase change of the refrigerant, the improvement comprising:

• a suction line fluidly connecting the evaporator chamber to the inlet of the compressor, said suction line being sealed about an opening in the shell and having an open distal end projecting into the chamber below the seal;
• and
• said suction line and said screw compressor positioned with respect to said evaporator and a reservoir means positioned within the chamber and below said suction line, thereby defining means for collecting lubrication oil migrating down said suction line during low load operation of the compressor so that when the level of oil in said reservoir means reaches a predetermined level, the opening in the distal end of the line will be restricted thereby increasing the flow velocity proximate thereto causing reintroduction of the oil into the compressor.