Freeze tunnel and methods of use

Abstract

A freeze tunnel can have a conveyor configured to move food product from a first end to a second end. At least one first cooling unit and at least one first fan can be positioned on the first side of the conveyor, and at least one second cooling unit and at least one second fan can be positioned on the second side of the conveyor. The fans can cooperate to circulate air inside the freeze tunnel in two opposite rotational directions.

We claim: 
     
         1 . A freeze tunnel comprising:
 a first end and a second end;   a conveyor configured to move a plurality of individual pieces of food product from the first end to the second end, the conveyor having a first side and a second side;   at least one first cooling unit and at least one first fan positioned on the first side of the conveyor; and   at least one second cooling unit and at least one second fan positioned on the second side of the conveyor,   wherein the at least one first and the at least one second cooling units are not vertically aligned with the conveyor, and the at least one first and second fan cooperate to circulate air inside the freeze tunnel in two opposite rotational directions.   
     
     
         2 . The freeze tunnel of  claim 1 , wherein the two opposite rotational directions comprise a first air flow pattern that rotates counter-clockwise when viewed along a longitudinal direction of the freeze tunnel and a second air flow pattern that rotates clockwise when viewed along the longitudinal direction of the freeze tunnel, and
 wherein, in the vicinity of the conveyor, the first and second air flow patterns move in the same general direction.   
     
     
         3 . The freeze tunnel of  claim 1 , wherein the at least one first and second cooling units are positioned in the freeze tunnel at locations lower than the conveyor and the at least one first and second fans are positioned in the freeze tunnel at locations higher than the conveyor. 
     
     
         4 . The freeze tunnel of  claim 3 , wherein the at least one first fan is configured to pull air from an area above the conveyor and to blow the air downward towards the at least one first cooling unit, and the at least one second fan is configured to pull air from an area above the conveyor and to blow the air downward towards the at least one second cooling unit. 
     
     
         5 . The freeze tunnel of  claim 1 , wherein the at least one first cooling unit comprises a plurality of first cooling units that extend substantially along the length of the freeze tunnel, and the at least one second cooling unit comprises a plurality of second cooling units that extend substantially along the length of the freeze tunnel, the plurality of second cooling units being positioned generally opposite the plurality of first cooling units relative to the conveyor. 
     
     
         6 . The freeze tunnel of  claim 5 , comprising:
 a first cooling section having at least one of the plurality of first cooling units and at least one of the plurality of second cooling units;   a second cooling section having at least one of the plurality of first cooling units and at least one of the plurality of second cooling units;   a third cooling section having at least one of the plurality of first cooling units and at least one of the plurality of second cooling units; and   a first baffle member positioned between the first and second cooling sections and a second baffle member positioned between the second and third cooling sections.   
     
     
         7 . The freeze tunnel of  claim 6 , wherein the first cooling section comprises a pre-cooling section that has an inner air temperature of between about 40 and 50 degrees Fahrenheit at an exit end, and the second cooling section comprises an intermediate cooling section that is configured to cool an outside surface of the pieces of food product to a temperature below a solidification point of oil on the outside surface of the pieces of food product. 
     
     
         8 . The freeze tunnel of  claim 7 , wherein the conveyor comprises a first conveyor that transfers the food product through the first cooling section, a second conveyor that transfers the food product through the second cooling section, and a third conveyor that transfers the food product through the third cooling section, the freeze tunnel further comprising:
 a product exchange between the second and third conveyor causes the pieces of food product to be shaken up to reduce clumping that is caused by the solidification of oil on the surfaces of adjacent pieces of food product.   
     
     
         9 . The freeze tunnel of  claim 8 , wherein the second cooling section comprises a temperature adjustment member that can adjust the temperature of the second cooling section to a temperature at which the oil on the outside surface of pieces of the food product will solidify before the food product reaches the product exchange between the second and third conveyors, and
 wherein the adjustable temperature range of the second cooling section is between about 20 and 60 degrees Fahrenheit.   
     
     
         10 . The freeze tunnel of  claim 9 , wherein the temperature adjustment member comprises a device for changing the temperature of the second cooling section while the freeze tunnel is in operation. 
     
     
         11 . A method of freezing individual pieces of food product, the method comprising:
 advancing the food product into a freeze tunnel on a conveyor;   providing a first cooling unit on a first side of the conveyor and a second cooling unit on a second side of the conveyor;   circulating air through the first cooling unit and towards the conveyor in a first air flow pattern; and   circulating air through the second cooling unit and towards the conveyor in a second air flow pattern,   wherein the first and second air flow patterns are rotationally opposite from one another.   
     
     
         12 . The method of  claim 11 , wherein the first and second air flow patterns are in the same general direction as air from the first and second air flow patterns collectively passes through the conveyor. 
     
     
         13 . The method of  claim 11 , further comprising:
 providing a first fan on the first side of the conveyor and a second fan on the second side of the conveyor,   wherein the first and second fans circulate air in the freeze tunnel in the first and second air flow patterns, respectively, and air from both the first and second air flow patterns moves collectively upwards through the conveyor.   
     
     
         14 . The method of  claim 11 , further comprising:
 providing a plurality of the first cooling units on the first side of the conveyor and a plurality of second cooling units on the second side of the conveyor, the first and second cooling units extending substantially the length of the freeze tunnel;   advancing the food product through a first cooling section, the first cooling section having an internal temperature of between about 40 and 50 degrees Fahrenheit;   advancing the food product through a second cooling section, the second cooling section being maintained at a temperature that causes an outside surface of pieces of food product to freeze; and   advancing the food product through a third cooling section to substantially freeze the entirety of the pieces of food product.   
     
     
         15 . The method of  claim 14 , wherein the conveyor comprises at least a first, second, and third conveyor, the method further comprising:
 transferring the pieces of food product from the first conveyor to the second conveyor before the outside surfaces of the pieces of food product are frozen;   transferring the pieces of food product from the second conveyor to the third conveyor immediately after the outside surfaces of the pieces of food product are frozen in the second cooling section.   
     
     
         16 . The method of  claim 15 , further comprising:
 independently controlling depths of the food product on the first, second, and third conveyors.   
     
     
         17 . The method of  claim 15 , further comprising:
 adjusting the temperature of the second cooling section in real time to ensure that the outside surfaces of the pieces of food product solidify before the pieces of food product are transferred from the first conveyor to the second conveyor.   
     
     
         18 . A freeze tunnel having a first longitudinal half and a second longitudinal half extending the length of the freeze tunnel, the freeze tunnel comprising:
 a transport means for moving food product through the freeze tunnel, the transport means having a portion in the first longitudinal half and a portion in the second longitudinal half of the freeze tunnel;   a first cooling means for reducing the temperature in the freeze tunnel, the first cooling means being positioned in the first longitudinal half;   a second cooling means for reducing the temperature in the freeze tunnel, the second cooling means being positioned in the second longitudinal half;   a first air flow means for causing a first air flow pattern in the first longitudinal half; and   a second air flow means for causing a second air flow pattern in the second longitudinal half;   wherein the first and second air flow patterns are in rotationally opposite directions.   
     
     
         19 . The freeze tunnel of  claim 18 , wherein the first cooling means comprises a plurality of first cooling units that extend along a length of the freeze tunnel, and the second cooling means comprises a plurality of second cooling units that extend along the length of the freeze tunnel, and
 wherein the plurality of first cooling units are positioned opposite the plurality of second cooling units.   
     
     
         20 . The freeze tunnel of  claim 19 , wherein the first air flow pattern comprises a counter-clockwise rotation when viewed in a longitudinal direction from an entrance side of the freeze tunnel and the second air flow pattern comprises a clockwise rotation when viewed in the longitudinal direction from the entrance side of the freeze tunnel. 
     
     
         21 . The freeze tunnel of  claim 20 , wherein the freeze tunnel comprises a first cooling section, a second cooling section, and a third cooling section, and the first cooling section is separated from the second cooling section by a baffle and the second cooling section is separated from the third cooling section by a baffle, and
 wherein the second cooling section comprising a temperature adjustment means for adjusting the temperature of the second cooling section during operation of the freeze tunnel.