Abstract: A portable apparatus for recovering refrigerant from a refrigeration system and delivering the refrigerant to a refrigerant storage tank. The recovery is automatically terminated when the liquid refrigerant occupies 80% of the volume of the recovery tank. The apparatus includes a liquid sensing thermistor that is in contact with the entering refrigerant to the recovery machine. When liquid is detected, it is routed directly to the recovery tank. Gaseous refrigerant and any non-condensable gases from the top of the recovery tank are directed to the suction of a compressor then to a condenser and to a purge vessel that functions as a receiver. When the entering refrigerant is in a gaseous phase, it is routed to the suction of the compressor. A second liquid sensing thermistor is in contact with the gaseous refrigerant from the top of the recovery tank and if liquid is detected the recovery process is terminated.

Abstract: A portable purging apparatus that automatically removes air and non-condensable gases from an operating refrigeration system wherein refrigerant gas condenses at a cooling coil disposed in the upper portion of a purge vessel, the condensate falling to the bottom of the vessel where a pickup tube conveys the condensate out of the vessel and to a thermal expansion valve that meters refrigerant into the cooling coil, the outlet of the coil connecting to the suction line of the operating refrigeration system. Non-condensable gases collect in the top of the purge vessel and displace condensable gas around the cooling coil causing less heat load at the coil and a lower suction line temperature whereby a thermostat actuates a purging solenoid valve to discharge non-condensable gases from the purge vessel through a flow restricting orfice to the atmosphere.