Hot gas defrost system

A method of defrosting a heat exchanger coil in a refrigeration system comprising the steps of:

• discharging a portion of the gaseous heat exchange fluid from a compressor outlet into the inlet of a heat exchanger coil having ice accumulated thereon;
• circulating the heat exchange fluid through the coil wherein at least a portion of said heat exchange fluid is condensed such that heat is extracted therefrom to melt the ice accumulated on the coil;
• passing the condensed heat exchange fluid from the heat exchanger coil outlet into an accumulator which serves as a reservoir for refrigerant during heat transfer operations and a heat interchanger during defrost operations;
• by-passing a portion of the gaseous heat exchange fluid discharged from the compressor outlet and introducing said portion in heat exchange relationship with the liquid heat exchange fluid in the accumulator from the step of passing to thereby vaporize at least a portion of the liquid contained therein;
• and
• conducting gaseous heat exchange fluid from the accumulator into the compressor inlet.