Patent ID: 7722780

Claim:
A method of refrigerating a substance, comprising the steps of: compressing a refrigerant composition in a single stage system, to obtain a compressed composition, cooling the said compressed composition to obtain a cooled refrigerant; throttling the said cooled refrigerant, and passing the same, thereafter, through an evaporator for cooling the substance, characterized in that the said composition comprises: more than 25 molar percent but less than 30 molar percent of Nitrogen; at least some but less than 20 molar percent of Methane; more than 30 molar percent but less than 70 molar percent of a gas selected from Propane, Argon, Helium, Neon and combinations thereof wherein more than 30 molar percent of propane is always present and optionally up to 45 molar percent of Ethane, Ethylene and combinations thereof wherein if such Ethane/Ethylene combination is present, the molar percent of ethane is in the range of 5 to 40 percent.