| 摘要 |
A freezer that uses liquid cryogen as a refrigerant includes an inner vessel defining a storage chamber and an outer jacket generally surrounding the inner vessel so that an insulation space is defined there between. A heat exchanger is positioned in a top portion of the storage chamber and has an inlet in communication with a supply of the liquid cryogen refrigerant so that the liquid cryogen refrigerant selectively flows through the heat exchanger to cool the storage chamber while being vaporized. A purge line is in communication with the outlet of the heat exchanger and includes a purge outlet positioned over the exterior of the heat exchanger. A purge valve is positioned within the purge line so that the vaporized liquid cryogen from the heat exchanger is selectively directed to the exterior of the heat exchanger to reduce ice formation on the heat exchanger.
|
