Cooling container using phase change material and method for operating

Abstract

A cooling container having a coolant chamber and a product chamber. Cooling gases from the coolant chamber circulate between the coolant chamber and the product chamber to retain the latter at a desired low temperature. In one embodiment the cooling gases flow through a radiator disposed in the product chamber. In another embodiment a heat exchanger is provided on a divider wall between the coolant chamber and the product chamber. When a temperature sensor detects that the temperature in the product chamber exceeds a temperature set point, a controller opens valves that allow cool gases in the coolant chamber to circulate through the radiator or across the heat exchanger to lower the temperature in the product chamber.

I claim: 
     
         1 . A cooling container using phase change materials, the cooling container comprising:
 a container body having insulated side and bottom walls, an insulated center divider, a top opening defined by the side walls, and one or more lids, the side and bottom walls defining an interior compartment, the one or more lids for fitting over the top opening to seal off the compartment, the center divider separating the interior compartment into a coolant chamber and a product chamber, the coolant chamber sized for holding a coolant, the product chamber sized for holding products,   the center divider including first and second apertures, the coolant and product chambers in communication with each other through said first and second apertures,   a controller,   a power source in communication with the controller, and   a sensor disposed in the product chamber, the sensor in communication with the controller,   a fan in communication with the controller and in operative communication with the first aperture,   wherein when the sensor detects a temperature in the product chamber above a selected threshold, the controller is configured to activate the fan so that cool gases from the coolant chamber flow through the first aperture into the product chamber and gases from the product chamber are flow the second aperture back into the coolant chamber, thereby maintaining the temperature in the product chamber below said threshold.   
     
     
         2 . The cooling container of  claim 1  further comprising:
 the coolant including phase change materials. 
 
     
     
         3 . The cooling container of  claim 1  further comprising:
 a length of sealed conduit disposed in the product chamber extending between the first and second apertures for retaining cooling gases. 
 
     
     
         4 . The cooling container of  claim 3  wherein:
 the length of sealed conduit comprises one or more coils. 
 
     
     
         5 . The cooling container of  claim 1  wherein:
 the divider includes a sealed air gap. 
 
     
     
         6 . The cooling container of  claim 1  further comprising:
 a valve in communication with the first aperture for restricting the flow of gases from the coolant chamber to the product chamber to one direction, 
 wherein the controller is configured to activate the valve when the sensor detects a temperature in the product chamber above a selected threshold. 
 
     
     
         7 . The cooling container of  claim 1  wherein:
 the one or more lids comprises two lids, each of the two lids closing one of the coolant and product chambers. 
 
     
     
         8 . A cooling container using phase change materials, the cooling container comprising:
 a container body having insulated side and bottom walls, an insulated center divider, a top opening defined by the side walls, and one or more lids, the side and bottom walls defining a chamber, the one or more lids for fitting over the top opening to seal off the chamber, the center divider separating the chamber into a coolant chamber and a product chamber, the coolant chamber sized for holding a coolant, the product chamber sized for holding products,   a controller,   a power source in communication with the controller,   a sensor in communication with the controller, the sensor disposed in the product chamber, and   the center divider including first and second partitions and first and second apertures, the first and second partitions spaced apart to define a circulation chamber, the coolant and circulation chambers in communication with each other through said first and second apertures, the first partition including a heat exchanger having a cold side and a hot side, the cold side extending into the circulation chamber and the hot side extending into the product chamber such that heat in the air in the product chamber is transferred from the hot side heat exchanger to the cold side heat exchanger into the circulation chamber,   a fan for driving air from the coolant chamber to the circulation chamber through the first aperture, the fan in communication with the controller,   wherein when the sensor detects a temperature in the product chamber above a selected threshold, the controller is configured to activate the fan so that cool air from the coolant chamber is driven into the circulation chamber through the first aperture, heat is extracted from the product chamber via the heat exchanger into the circulation chamber, and warmed air from the circulation chamber flows through the second aperture back into the coolant chamber, thereby maintaining the temperature in the product chamber below said threshold.   
     
     
         9 . The cooling container of  claim 8  further comprising:
 a valve in communication with the second aperture for preventing back flow of gases from the circulation chamber to the coolant chamber. 
 
     
     
         10 . The cooling container of  claim 8  further comprising:
 the second partition including a sealed air gap. 
 
     
     
         11 . A method for controlling the temperature in a cooling container, the container using phase change materials, the method comprising:
 detecting the temperature in a product chamber in a cooling container,   activating a fan in a cooling chamber in the cooling container to circulate cooling gases between the cooling chamber and the product chamber.