Freezer with positive pressure storage cabinet

Abstract

A freezer for the storage of blood plasma and other blood products is disclosed.

1 . An apparatus comprising,
 a freezer comprising an encloseable storage space and an aperture configured to permit fluid communication between the storage space and atmosphere, and   a positive pressure assembly configured to communicate ambient air through the aperture to induce a positive pressure in the storage space relative to atmosphere.   
   
   
       2 . The apparatus of  claim 1 , wherein the freezer further comprises a door movable between an open position and a closed position enclosing the storage space. 
   
   
       3 . The apparatus of  claim 1 , wherein the positive pressure assembly comprises a plenum and a positive pressure source coupled to the plenum. 
   
   
       4 . The apparatus of  claim 3 , wherein the plenum includes an outlet in fluid communication with the aperture. 
   
   
       5 . The apparatus of  claim 4 , wherein the positive pressure source comprises a device selected from the group of a fan, a blower, or a compressor. 
   
   
       6 . The apparatus of  claim 1 , further comprising a conduit having an outlet, the conduit in fluid communication with the positive pressure assembly and configured to be received in the aperture of the freezer such that the outlet directs the ambient air into the storage space. 
   
   
       7 . The apparatus of  claim 6 , wherein the freezer further comprises a chiller including refrigeration coils and the outlet of the conduit is positioned to direct flow over the refrigeration coils. 
   
   
       8 . The apparatus of  claim 7 , wherein the chiller includes a heating element configured to defrost the refrigeration coils. 
   
   
       9 . The apparatus of  claim 8 , wherein the conduit comprises a drain line of the freezer. 
   
   
       10 . The apparatus of  claim 9 , wherein the drain line includes a heating element. 
   
   
       11 . The apparatus of  claim 1 , wherein the positive pressure assembly develops a pressure within the storage space of about 0.25 inches of water above atmospheric pressure. 
   
   
       12 . The apparatus of  claim 1 , wherein the positive pressure assembly is secured to the freezer. 
   
   
       13 . A method of pressurizing a storage space of a refrigerator comprising:
 sealing the storage space within the freezer relative to ambient air,   establishing a fluid communication path from a positive pressure source external to the freezer to the storage space in the freezer,   positioning the positive pressure source to intake ambient air, and   operating the positive pressure source to direct the air into the storage space and thereby develop a positive pressure within the storage space of the freezer relative to the ambient air.   
   
   
       14 . The method of  claim 13  further comprising the step of directing the flow of pressurized air over a refrigeration coil within the storage space of the freezer. 
   
   
       15 . The method of  claim 13  further comprising the step of operating the positive pressure source continuously. 
   
   
       16 . The method of  claim 15  further comprising the step of developing a static pressure within the storage space of the freezer. 
   
   
       17 . A freezer comprising,
 a cabinet having an external surface and defining an encloseable storage space therein and an aperture forming a fluid communication path between the storage space and the external surface,   a door coupled to the cabinet and moveable between an open position and a closed position, wherein the storage space is enclosed when the door is in the closed position,   a chiller comprising refrigeration coils and a fan, the chiller housed within the storage space, and   a positive pressure source coupled to an external surface of the cabinet, the positive pressure source having an inlet and an outlet,   wherein the positive pressure source receives ambient air in the inlet, pressurizes the air, and communicates the pressurized air through the aperture and into the storage space.   
   
   
       18 . The freezer of  claim 17 , further comprising a conduit configured to be received in the aperture, the conduit coupled to the outlet of the positive pressure source and communicating the flow of pressurized air into the storage space. 
   
   
       19 . The freezer of  claim 18 , wherein the conduit directs the flow of fluid over the refrigeration coils. 
   
   
       20 . The freezer of  claim 19 , wherein the conduit comprises a drain line of the freezer.