Patent ID: 7958738

Claim:
A direct expansion ammonia refrigeration system, comprising: a source of liquid ammonia refrigerant; a direct expansion ammonia evaporator; a compressor which is coupled in fluid flowing relation relative to the source of liquid ammonia refrigerant, and which provides the liquid ammonia refrigerant to the direct expansion ammonia evaporator; an accumulator vessel defining an internal cavity having a liquid region, and a vapor region, and wherein the vapor region is coupled in fluid receiving relation relative to the direct expansion ammonia evaporator, and in fluid delivering relation relative to the compressor, and wherein the liquid region contains aqueous liquid ammonia received from the evaporator; and a heat exchanger vessel coupled in fluid receiving relation relative to the liquid region of the accumulator vessel, and in fluid delivering relation relative to the vapor region of the accumulator vessel, and wherein the heat exchanger vessel includes a heating element which vaporizes the aqueous liquid ammonia so as to deliver substantially dry ammonia vapor to the vapor region of the accumulator vessel, and wherein the substantially dry ammonia vapor is subsequently delivered to the compressor.