Pulsed cryogen freezer

Abstract

A cryogenic freezer and a method of controlling temperature within the cryogenic freezer. The cryogenic freezer includes an inner vessel. The inner vessel defines a storage chamber. The cryogenic freezer includes an outer vessel surrounding the inner vessel. The outer vessel may define a vacuum-insulated space in between the outer vessel and the inner vessel. The cryogenic freezer includes a temperature sensor configured to measure a temperature within the storage chamber. The cryogenic freezer includes a controller coupled to the temperature sensor. The controller is configured to pulse an amount of cryogen into the storage container to control the temperature within the storage container.

What is claimed is: 
     
         1 . A freezer, comprising:
 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 and configured to:
 determine a difference between the temperature within the storage container and a set point temperature; 
 pulse an amount of medium into the storage container to control the temperature within the storage container; and 
 determine a timing or a frequency of the pulsing of the amount of medium into the storage container based on the difference, 
 wherein the controller is configured to pulse the amount of medium into the storage container based on the timing or the frequency. 
   
     
     
         2 . 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 is greater than or equal to the set-point temperature.   
     
     
         3 . The method of  claim 2 , comprising:
 measuring or detecting, by the processor and using a cryogen level sensor, the amount of cryogen in the storage chamber; and   pulsing, by the processor and using the outlet and the cryogen source, the amount of cryogen into the storage chamber based on the amount of cryogen in the storage chamber.   
     
     
         4 . The method of  claim 3 , wherein pulsing the amount of cryogen into the storage chamber includes:
 decreasing a frequency or a timing of the pulsing when a detected or measured amount of cryogen within the storage chamber is greater than or equal to a threshold amount or when the temperature is less than a threshold temperature; and   increasing the frequency or the timing of the pulsing when the detected or measured amount of cryogen within the storage chamber is less than the threshold amount or when the temperature is greater than the threshold temperature.   
     
     
         5 . The method of  claim 2 , comprising:
 determining a difference between the temperature within the storage chamber and the set-point temperature;   determining a timing or a frequency of the pulsing of the amount of cryogen into the storage chamber based on the difference; and   pulsing the amount of cryogen into the storage chamber based on the timing or the frequency.   
     
     
         6 . The method of  claim 2 , wherein the pulsing the amount of cryogen into the storage chamber comprises delivering or dispersing the cryogen into the storage chamber by an outlet that is positioned at a bottom of the storage chamber. 
     
     
         7 . The method of  claim 2 , wherein the pulsing the amount of cryogen into the storage chamber comprises:
 adjusting a position of an outlet valve to (i) open, (ii) partially open, or (iii) close the outlet; or   controlling the cryogen source to provide the cryogen through to the outlet valve.   
     
     
         8 . The method of  claim 7 , wherein the outlet is positioned at a bottom of the storage container. 
     
     
         9 . The method of  claim 6 , wherein the cryogen is pressurized for transfer to the outlet. 
     
     
         10 . The method of  claim 2 , further comprising:
 determining, by the processor, a timing or a frequency of the pulsing of the amount of the cryogen into the storage chamber,   wherein the pulsing is at the timing or the frequency.   
     
     
         11 . The method of  claim 10 , further comprising:
 determining a difference between the temperature and the set-point temperature; and   setting the timing or the frequency of the amount of the cryogen based on the difference.   
     
     
         12 . A method of controlling temperature within a cryogenic freezer, comprising:
 measuring or detecting, by a processor and using a cryogen level sensor, an amount of cryogen in a storage chamber of the cryogenic freezer; and   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 based on the amount of cryogen in the storage chamber;   decreasing a frequency or a timing of the pulsing when the detected or measured amount of cryogen within the storage chamber is greater than or equal to a threshold amount; and   increasing the frequency or the timing of the pulsing when the detected or measured amount of cryogen within the storage chamber is less than the threshold amount.   
     
     
         13 . The method of  claim 12 , wherein the pulsing the amount of cryogen into the storage chamber comprises delivering or dispersing the cryogen into the storage chamber by an outlet that is positioned at a bottom of the storage chamber. 
     
     
         14 . The method of  claim 12 , wherein the pulsing the amount of cryogen into the storage chamber comprises:
 adjusting a position of an outlet valve to (i) open, (ii) partially open, or (iii) close the outlet; or   controlling the cryogen source to provide the cryogen through to the outlet valve.   
     
     
         15 . The method of  claim 14 , wherein the outlet is positioned at a bottom of the storage container. 
     
     
         16 . The method of  claim 13 , wherein the cryogen is pressurized for transfer to the outlet. 
     
     
         17 . A computer-readable medium storing instructions that when executed by a processor of a temperature control apparatus of a cryogenic freezer, cause the processor to perform a method of controlling temperature within the cryogenic freezer, the method 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 is greater than or equal to the set-point temperature.   
     
     
         18 . The computer readable medium according to  claim 17 , wherein the method further comprises:
 measuring or detecting, by the processor and using a cryogen level sensor, the amount of cryogen in the storage chamber; and   pulsing, by the processor and using the outlet and the cryogen source, the amount of cryogen into the storage chamber based on the amount of cryogen in the storage chamber.   
     
     
         19 . The computer readable medium according to  claim 18 , wherein pulsing the amount of cryogen within the storage chamber includes:
 decreasing a frequency or a timing of the pulsing when the detected or measured amount of cryogen within the storage chamber is greater than or equal to a threshold amount or when the temperature is less than a threshold temperature; and   increasing the frequency or the timing of the pulsing when the detected or measured amount of cryogen within the storage chamber is less than the threshold amount or when the temperature is greater than the threshold temperature.   
     
     
         20 . The computer readable medium according to  claim 17 , wherein the method further comprises:
 determining a difference between the temperature within the storage chamber and the set-point temperature;   determining a timing or a frequency of the pulsing of the amount of cryogen into the storage chamber based on the difference; and   pulsing the amount of cryogen into the storage chamber based on the timing or the frequency.