Apparatus for blast freezing palletized product

Abstract

Apparatus for blast freezing palletized products is disclosed in which tall racks have openings on at least one side that connect to a plenum chamber, against which stacked pallets can be placed one above another as well as beside one another adjacent the plenum openings, but with the rack providing only one pallet depth to optimize circulation of regular warehouse freezing air through the pallets at a rapid rate for rapid blast freezing. As another example, there are vertically adjustable panels in a tall rack to accommodate different height palletized products stacked one above another, in a way that allows for sealing between the plenum chamber and the palletized products on one side of the palletized product without either substantial blockage of air flow through the side of the palletized product and without allowing a substantial gap between the palletized product and the plenum that would allow a substantial bypass of flow through the palletized product. In particular, as to a particularly preferred embodiment of the invention, there is disclosed the fixing of the position of adjustable panels through the use of pins that could be inserted into any one of a series of vertically arranged holes to achieve any one of multiple discrete heights that are securely positioned, yet readily adjustable. The vertical adjustability of a member that has a rigid component that may or may not also contain a cushioned or flexible seal allows for much more durability, versatility and suitability for accommodating palletized products of various heights.

1 . A blast freezer for an array of pallet assemblies each including a plurality of products supported by a pallet, the blast freezer comprising:
 a source of freezing air,   an air flow chamber including an air flow handler and an array of side air openings for facilitating a flow of freezing air between the air flow chamber and said freezing air source; and   a pallet rack for positioning the array of pallet assemblies relative to the array of side air flow openings for channeling the flow of freezing air between the air flow chamber and the freezing air source through the array of pallet assemblies, wherein the pallet rack has a depth corresponding to the thickness of a single pallet assembly to facilitate freezing of the products supported by the pallet assemblies.   
     
     
         2 . The blast freezer of  claim 1 , wherein the pallet assemblies include air flow passages for facilitating the flow of freezing air through the pallet assemblies. 
     
     
         3 . The blast freezer of  claim 2 , wherein each air flow passage is defined by a spacer between at least two products. 
     
     
         4 . The blast freezer of  claim 1 , further comprising:
 an air flow barriers interactive with the pallet assemblies for inhibiting the flow of freezing air around a perimeter of each of the pallet assemblies into the air flow chamber as freezing air flows between the air flow chamber and said freezing air source through the pallet assemblies.   
     
     
         5 . The blast freezer of  claim 4 , wherein the air flow barrier is selected from a group consisting of at least one pallet seal encircling a perimeters of the air openings and at least one pallet flap adjacent the perimeters of the pallet assemblies. 
     
     
         6 . The blast freezer of clam  4 ,
 wherein the air flow barrier includes at least one pallet seal encircling the perimeters of each of the air openings; and   wherein the pallet rack is for positioning a side of each of the pallet assemblies against the at least one pallet seal.   
     
     
         7 . The blast freezer of  claim 6 , wherein each of the at least one pallet seals has an upper portion that is vertically adjustable to allow for different height pallet assemblies to be used yet still have sealing along the side of a pallet assembly near its top. 
     
     
         8 . The blast freezer of  claim 6 , wherein the pallet rack includes pallet guides for guiding the pallet assemblies against their corresponding pallet seals when placed in position. 
     
     
         9 . The blast air freezer of  claim 1 , wherein the air flow handler pulls freezing air through the pallet assemblies into the air flow chamber. 
     
     
         10 . The blast air freezer of  claim 1  wherein the blast freezer is positioned within a freezer storage warehouse and the source of freezing air used for blast freezing is the same as is used for storage, but with the blast freezer forcing higher air flow rates through the pallets being frozen compared to the flow rates supplied to the stored, already frozen pallets. 
     
     
         11 . The blast air freezer of  claim 10  in which the source of freezing air is between 10 degrees and −20 degrees Fahrenheit. 
     
     
         12 . The blast air freezer of  claim 11  in which the source of freezing air is at about −10 degrees Fahrenheit. 
     
     
         13 . The blast freezer of  claim 1  wherein the side openings in the plenum that are adjacent pallet assemblies have vertically adjustable panels at the top of the openings to accommodate different height palletized products. 
     
     
         14 . The blast freezer of  claim 13  in which said panels are rigid. 
     
     
         15 . The blast freezer of  claim 14  additionally comprising locating pins between the panels and racks to allow for ready adjustment of the vertical position of said vertically adjustable panels. 
     
     
         16 . The blast freezer of  claim 15  in which the rack has a series of vertically arranged holes for pin engagement at different heights to permit ready adjustment of panel height. 
     
     
         17 . The blast freezer of  claim 1  in which said rack is sized to allow for an array of at least three pallet assemblies high and at least six pallet assemblies wide, while maintaining a depth of only one pallet assembly. 
     
     
         18 . The blast freezer of  claim 17  in which said rack is sized to allow for an array of at least four pallet assemblies high and at least eight pallet assemblies wide, while maintaining a depth of only one pallet assembly. 
     
     
         19 . The blast freezer of  claim 18  in which said rack is sized to allow for an array of five pallet assemblies high and at least ten pallet assemblies wide, while maintaining a depth of only one pallet assembly. 
     
     
         20 . The blast freezer of  claim 1  in which said rack is sized to allow for an array of five pallet assemblies high and at least ten pallet assemblies wide, while maintaining a depth of only one pallet assembly. 
     
     
         21 . The blast freezer of  claim 1  in which the an air flow handler has the capacity to provide for an air flow rater of freezing air through the palletized products at greater than 50 feet per minute. 
     
     
         22 . The blast freezer of  claim 1  in which the an air flow handler has the capacity to provide for an air flow rater of freezing air through the palletized products at greater than 100 feet per minute. 
     
     
         23 . The blast freezer of  claim 1  in which for each position in said pallet rack for positioning a pallet assembly there is just one corresponding side air opening in said air flow chamber. 
     
     
         24 . The blast freezer of  claim 1  comprising an air flow barrier interactive with the pallet assemblies for inhibiting the flow of freezing air around a perimeter of each pallet assembly as freezing air flows between the air flow chamber and the freezing air source through the pallet assemblies. 
     
     
         25 . The blast freezer of  claim 24 , wherein the air flow barrier is selected from a group consisting of at least one pallet seal encircling a perimeter of the air opening and at least one pallet flap adjacent the perimeter of the pallet assembly.