Purger for refrigeration system

A purging apparatus for purging non-condensable gas from a operating closed loop refrigeration system comprising a compressor, discharge line, condenser, condenser drain line, receiver, liquid line, metering device, evaporator and suction line to the compressor, said purging apparatus including means for transferring refrigerant gas and non-condensable gas from the top of said system receiver through a first electrically operatable valve to a vertical enclosed cylindrical vessel, said vessel having a cooling coil disposed in the upper portion of the vessel for the purpose of condensing said refrigerant gas, the condensate thereof falling to the bottom of said vessel, piping is provided with a second operatable valve and is disposed at the bottom of said vessel to convey said condensate out of the vessel and through said second electrically operatable valve to a metering device, said metering device connects to the inlet of said cooling coil providing evaporation and cooling in the coil whereby the outlet of the cooling coil connects with the system suction line, the non-condensable gas enters the purger vessel from the said system receiver and, being of lower density than the refrigerant gas, collects at the top of the vessel and displaces the refrigerant gas at the cooling coil thereby causing a loss of refrigerating load and subsequently less superheat and a lower temperature at the outlet of the cooling coil, a thermostat with a sensing bulb is provided at the cooling coil outlet, said thermostat comprises means to close a contact when the temperature falls to a predetermined setpoint thereby energizing a third electrically operatable valve connected by a line to the top of the purger vessel for discharging non-condensable gases through a flow restricting orfice to the atmosphere, said thermostat de-energizes said third electrically operatable valve at a predetermined rise of the temperature at the coil outlet when the quantity of non-condensable gas in the said purger is reduced;

• said refrigeration system condenser having an inlet header and an outlet header, said outlet header is provided with means for passing non-condensable gases trapped in an upper portion of said outlet header through a shut off valve and a small diameter tube, said tube extending from said upper portion of said outlet header to a location above said condenser drain line which connects and extends downward from the said outlet header, said tube extending downward into the condenser drain thereby defining means for bleeding said non-condensable gas into the flow of liquid and gaseous refrigerant into said receiver.