Apparatus and Method for Chilling or Freezing Objects Utilizing a Rotary Drum Having Prominences Formed on an Inner Surface Thereof

Abstract

In an apparatus and method for chilling or freezing objects, an interior surface of a rotating drum includes recesses formed between prominences extending inwardly from the interior surface. One or more liquid CO 2 nozzles inject solid CO 2 towards the interior surface. The injected snow replenishes a depth of solid CO 2 in empty or partially empty recesses and/or provides a fresh layer of solid CO 2 on top of the objects. Because the interior surface is made of polyethylene and the depth of solid CO 2 is replenished in empty or partially empty recesses, the product/drum sticking problem experienced by conventional apparatuses and methods is reduced or avoided. Optionally, the CO 2 snow is injected into empty or partially empty recesses by at least one first liquid CO 2 nozzle and is deposited on top of the objects by at least one second liquid CO 2 nozzle so that each opposing surface of the object is in direct contact with solid CO 2 .

What is claimed is: 
     
         1 . An apparatus for chilling or freezing objects, the apparatus comprising a rotatable drum defining an enclosure having an interior surface, an inlet at one end of the drum, an outlet at an opposing end of the drum, one or more liquid CO 2  nozzles disposed in an interior of the drum each one of which is adapted to inject a stream of solid CO 2  into the enclosure towards the interior surface, wherein:
 the interior surface of the drum is comprised of polyethylene having prominences molded into the polyethylene;   portions of the interior surface in between prominences form recesses relative to the prominences that are adapted and configured to retain a depth of solid CO 2 ; and   the prominences are not directional vanes.   
     
     
         2 . The apparatus of  claim 1 , wherein:
 said at least two liquid CO 2  nozzles comprise at least one first liquid CO 2  nozzle and at least one second liquid CO 2 ;   each of said at least one first liquid CO 2  nozzles being disposed in an interior of the drum and being adapted, configured, and oriented to provide a first stream of solid CO 2  towards a first angular position on the inner surface;   each of said at least one second liquid CO 2  nozzle being disposed in the drum interior and being adapted, configured, and oriented to provide a second stream of solid CO 2  towards a second angular position on the inner surface; and   the first angular position is between 70-110° and/or 250-290° with respect to vertical and the second angular position is between 160-200° with respect to vertical.   
     
     
         3 . The apparatus of  claim 1 , further comprising directional vanes on the interior surface. 
     
     
         4 . The apparatus of  claim 1 , wherein the prominences extend approximately 0.25 to 1 inches from the interior surface. 
     
     
         5 . The apparatus of  claim 4 , further comprising directional vanes on the interior surface. 
     
     
         6 . A method for chilling or freezing objects, comprising the steps of:
 providing the apparatus of  claim 1 ;   rotating the drum;   introducing the objects into the interior the drum; and   injecting a stream of solid CO 2  into the enclosure towards the interior surface from one or more liquid CO 2  nozzles, wherein the solid CO 2  is deposited in the recesses and/or on top of the objects; and   removing the objects from the outlet of the drum.   
     
     
         7 . The method of  claim 6 , wherein:
 said at least two liquid CO 2  nozzles comprise at least one first liquid CO 2  nozzle and at least one second liquid CO 2 ;   each of said at least one first liquid CO 2  nozzles being disposed in an interior of the drum and injects a first stream of solid CO 2  towards a first angular position on the inner surface;   each of said at least one second liquid CO 2  nozzle being disposed in the drum interior and injects a second stream of solid CO 2  towards a second angular position on the inner surface; and   the first angular position is between 70-110° and/or 250-290° with respect to vertical and the second angular position is between 160-200° with respect to vertical.   
     
     
         8 . The method of  claim 7 , wherein the first stream(s) deposits a fresh layer of solid CO 2  in the recesses and the second stream(s) deposits solid CO 2  on top of the objects tumbling at or adjacent to a bottom of the drum. 
     
     
         9 . The method of  claim 6 , wherein the objects are food products. 
     
     
         10 . The method of  claim 9 , wherein the food products are meat products.