Pulsed cryogen freezer

A freezer for using cryogen as a refrigerant, comprising:

• an inner vessel defining a storage chamber;
• an outer vessel surrounding the inner vessel and defining a vacuum-insulated space in between the outer vessel and the inner vessel;
• a temperature sensor configured to measure a temperature within the storage chamber;
• and
• a controller coupled to the temperature sensor and configured to:
• determine a difference between the temperature within the storage container and a set point temperature;
• pulse an amount of cryogen into the storage container to control the temperature within the storage container;
• and
• wherein the controller is configured to pulse the amount of medium into the storage container based on the difference.

A method of controlling temperature within a cryogenic freezer, comprising:

• measuring or detecting, by a processor and using a temperature sensor, a temperature within a storage chamber of the cryogenic freezer;
• determining, by the processor, whether the temperature is greater than or equal to a set-point temperature;
• and
• pulsing, by the processor and using an outlet and a cryogen source, an amount of cryogen into the storage chamber when the temperature exceeds the set-point temperature.

A method of controlling temperature within a cryogenic freezer having a vessel defining a storage chamber, a first sensor configured to measure a temperature within the storage chamber, and a controller coupled to the first sensor, the method comprising:

• determining, by the controller, a difference between the temperature within the storage container and a set point temperature;
• pulsing, by the controller and using an outlet and a cooling medium source, an amount of cooling medium into the storage container to control the temperature within the storage container;
• determining, by the processor, the pulsing of the amount of cooling medium into the storage container based on the difference,
• wherein the determining the pulsing comprises (1) opening by the controller a valve to introduce cooling medium into the storage container or (2) closing by the controller the valve to not introduce cooling medium into the storage container.