Method and apparatus for freezing products using cryogen with work from expansion of cryogen used for further refrigeration

摘要

A cryogenic liquid selected from liquid nitrogen and liquid air (in tank 10) is compressed isenthalpically to a pressure of at least 10 bar gauge (pump 11). The cryogenic liquid is vaporized in evaporator 12 of freezer 15 and then passes through work expander 16. It is then discharged to further refrigerate product in the freezer.