Hanbell RC2-100AF, Manual

Page: 99 / 117

98
For system with flooded evaporator at HFC and R22 application, a separate oil rectifier from the evaporator or the
low-pressure receiver is required. Basically the oil/refrigerant mixture should be drawn off at several points in the
oil-rich phase of the liquid level. Using means of heat exchange to evaporate the refrigerant fraction (e.g. in a
counter flow with the warm refrigerant liquid) then feed back the oil via the suction gas line. Checking the oil level
in the external oil separator is required to ensure sufficient miscibility (oil/ refrigerant) under the corresponding
operating conditions in the evaporator or oil separator. When the oil circulation problem cannot be solved, a
secondary oil separator is required to minimize the oil carryover to the system.
b. Piping arrangement
In the case of single compressor, the suction line design before compressor should have a sufficiently large
volume and should not be angled towards the compressor. Please refer to figure below for details.
In the case of parallel compounding, the suction line runs below the level of compressor is recommended to
provide the maximum possible safety. In system where liquid slugging cannot be avoided (e.g. system with long
standstill under a pressure difference, hot gas defrost), the suction header shall able to take over the function of a
liquid separator. Please refer to figures below for design reference.
Suction line design before compressor (single compressor)
Suction line design before compressors (parallel compounding)