Food product freezing apparatus

Abstract

A continuous conveyor transports food products in, through and out of a rectangular freezing vault containing a blower and a refrigeration coil. The conveying strand is made up of a series of individual plates attached outwardly of the chain connecting the plates and is free to flex in only one direction. Within the vault the conveyor travels about two parallel elongated spiral networks, each including two vertical shafts supporting a stacked array of rotating sprockets. A crossover strand connects the two networks at the base of two adjacent shafts and a second crossover strand connects at the top of the opposite pair of shafts. The top crossover strand is brought outside the vault and there travels about a driving sprocket and an idler forming an outside loop enclosing a work table for performing operations on the products. The outside loop traces out an asymmetrical geometrical figure having two parallel sides, with the driver located at the acute angle formed therein. The driving sprocket can be sized independently of the other sprockets over which the conveying strand travels within the vault. The vault itself is divided into two chambers, one a vestibule through which the products travel as they enter or exit the vault, and serving to isolate the second chamber from the outside air. The second chamber contains the conveyor networks, the blower and refrigeration coil. The cooling is accomplished by circulating the air within the compartment in a direction transverse to the paths over which the conveyor travels. Deflection systems are employed to insure complete distribution and effective cooling of the products. The blowers and refrigeration coil are located above the conveyor networks along substantially the entire length of the conveyor networks.

Having described my invention, what I claim as new and desired to secure by Letters Patent is: 
     
       1. A food freezing apparatus comprising: a vault;   a continuous conveying means for transporting food products into, through and out of said vault, said conveying means traveling primarily in at least one network along .Iadd.vertical .Iaddend.substantially parallel planes within said vault;   a refrigeration coil;   means for circulating air in heat exchange with said coil and over said products in a direction substantially parallel to a plane perpendicular to the primary planes of travel of said conveying means within said vault; and a bulkhead within said vault forming a first and second chamber within said vault, said food products passing into and out of said vault through said first chamber, said second chamber containing said means for circulating air, said coil and said networks, wherein said bulkhead is positioned substantially perpendicular to the primary planes of travel of said conveying means and parallel to said air circulation direction.   
     
     
       2. Apparatus in accordance with claim 1 wherein said bulkhead is formed such that the temperature of said second chamber is substantially lower than the ambient temperature outside said vault. 
     
     
       3. Apparatus in accordance with claim 2 wherein said vault is formed with thermally insulating outside walls and said bulkhead is formed of a non-thermally insulating material. 
     
     
       4. A food freezing apparatus comprising: a vault;   a continuous conveying means for transporting food products into, through and out of said vault, said conveying means traveling primarily in at least one network along .Iadd.vertical .Iaddend.substantially parallel planes within said vault;   a refrigeration coil;   means for circulating air in heat exchange with said coil and over said products in a direction substantially parallel to a plane perpendicular to the primary planes of travel of said conveying means within said vault; and a bulkhead within said vault forming a first and second chamber within said vault, said food products passing into and out of said vault through said first chamber, said second chamber containing said means for circulating air, said coil and said networks, wherein said bulkhead is positioned substantially perpendicular to the primary planes of travel of said conveying means and parallel to said air circulation direction, and further comprising, access aisles within said second chamber, external of said conveying means within said second chamber and running substantially parallel to said conveying means; said means for circulating air and said coil extending substantially the length of said networks and located above said networks; said circulating means nearer one corner of said second chamber; and hinged turning vanes extending substantially the length of said networks located within the other three corners and extending into the aisles of said chamber.   
     
     
       5. The apparatus as described in claim 4 which further comprises deflecting plates for increasing the heat transfer from the base of said conveying means, said plates directing the flow of air in said second chamber against the base of said conveying means. 
     
     
       6. A food product freezing apparatus comprising: a generally rectangular freezing vault,   cooling means within said vault;   continuous conveying means including a series of product carrying plates for transporting said food products into, through and out of said vault, said conveying means following a circuitous path within said vault, said path including a first elongated spiral network and a second elongated spiral network, the long axis of said spirals being aligned along the length of said rectangle, each network comprising two stacked arrays of rotatable members, said arrays being placed parallel to each other and connected by conveying strands passing alternately from one to the other, said networks being connected at the bottom rotatable members of two adjacent arrays by a bottom cross over strand and at the top rotatable members of the opposite two arrays by a top cross over strand, one of said cross over strands passing out of and into said vault through one of the short sides of said vault and forming an outside loop passing around an external rotatable member and encompassing an enclosed area suitable for placing machinery associated with said freezing apparatus.   
     
     
       7. The apparatus as described in claim 6 wherein said loop passes around a rotatable driving member substantially larger in diameter than the other rotatable members within said vault. 
     
     
       8. The apparatus as described in claim 6 wherein said outside loop passes around two external rotatable members and forms an asymmetrical geometrical figure having two parallel sides. 
     
     
       9. The apparatus as described in claim 6 wherein the external rotatable member, located at the furthest point from said vault, drives said conveying means. 
     
     
       10. The apparatus as described in claim 9 wherein said loop is in contact with said external rotatable member along an arc encompassing more than a 90° angle. 
     
     
       11. Apparatus as described in claim 9 wherein said loop passes around a rotatable driving member substantially larger in diameter than the other rotatable members within said vault. 
     
     
       12. A food product freezing apparatus comprising: a generally rectangular freezing vault,   convective cooling means and access aisles within said vault;   continuous conveying means capable of flexing in only one direction for transporting said food products into, through and out of said vault, said conveying means traveling primarily along parallel planes within said vault while following a first elongated spiral network and a second elongated spiral network, the long axis of said spirals being aligned with the length of said rectangle, each network comprising two stacked arrays of rotatable members, said arrays being placed parallel to each other and connected by strands passing alternately from one to the other, said networks being connected at the bottom rotatable members of two adjacent arrays by a bottom crossover strand and at the top rotatable members of the opposite two arrays by a top cross over strand, one of said crossover strands passing out of and into said chamber through one of the short sides of said vault and forming an outside loop encompassing an enclosed area external of said vault suitable for placing machinery associated with said freezing apparatus; and   said cooling means positioned to direct the flow of air within said vault along paths substantially parallel to a plane perpendicular to the primary planes of travel of said conveying means within said vault.   
     
     
       13. The apparatus as described in claim 12 wherein said cooling means comprises an air circulation means and a refrigeration coil. 
     
     
       14. The apparatus as described in claim 13 wherein both said circulation means and said refrigeration coil extend substantially the length of said networks. 
     
     
       15. The apparatus as described in claim 14 which further comprises: a set of turning vanes located within an access aisle within said vault, for turning the air stream from said refrigeration coil to direct it across said conveying means.   
     
     
       16. The apparatus as described in claim 15 which further comprises: supporting structure for said conveying means;   deflecting means attached to said supporting structure and located below said conveying means for directing the airflow toward said conveying means.   
     
     
       17. The apparatus as described in claim 12 wherein: said outside loop passes around first and second external rotatable members; the first rotatable member, located at a point farther from said vault than the second external rotatable member, drives said conveying means; said first external rotatable member being substantially larger in diameter than the rotatable members in the arrays within said vault; and said loop is in contact with said rotatable driving member along an arc encompassing more than a ninety degree angle. 
     
     
       18. The apparatus as described in claim 17 wherein said cooling means comprises an air circulation means and a refrigeration coil. 
     
     
       19. The apparatus as described in claim 18 wherein both said circulation means and said refrigeration coil extend substantially the length of said networks. 
     
     
       20. The apparatus as described in claim 19 which further comprises: a set of turning vanes located within an access aisle within said vault for turning the air stream from said refrigeration coil to direct it across said conveying means.   
     
     
       21. The apparatus as described in claim 20 which further comprises: supporting structure for said conveying means;   deflecting means attached to said supporting structure and located below said conveying means for directing the airflow toward said conveying means.   
     
     
       22. The improvement as described in claim 12 which further comprises: a bulkhead within said vault forming a first and second chamber within said vault;   said one connecting strand passing in both directions through said bulkhead and said first chamber by means of pass through windows located therein; and wherein said second chamber contains said cooling means.   
     
     
       23. The appartus as described in claim 22 wherein said cooling means comprises an air circulation means and a refrigeration coil. 
     
     
       24. The apparatus as described in claim 23 wherein both said circulation means and said refrigeration coil extend substantially the length of said networks. 
     
     
       25. The apparatus as described in claim 24 which further comprises: a set of turning vanes located within an access aisle within said second chamber for turning the air stream from said refrigeration coil to direct it across said conveying means.   
     
     
       26. The apparatus as described in claim 25 which further comprises: supporting structure for said conveying means;   deflecting means attached to said supporting structure and located below said conveying means for directing the airflow toward said conveying means.   
     
     
       27. The apparatus as described in claim 22 wherein: said outside loop passes around first and second external rotatable members; the first rotatable member, located at a point farther from said vault than the second external rotatable member, drives said conveying means; said first external rotatable member being substantially larger in diameter than the rotatable members in the arrays within said vault; and said loop is in contact with said rotatable driving member along an arc encompassing more than a ninety degree angle. 
     
     
       28. The apparatus as described in claim 27 wherein said cooling means comprises an air circulation means and a refrigeration coil placed downstream of said circulation means and upstream of said conveying means. 
     
     
       29. The apparatus as described in claim 28 wherein both said circultion means and said refrigeration coil extend substantially the length of said networks. 
     
     
       30. The apparatus as described in claim 29 which further comprises: a set of turning vanes located within an access aisle within said second chamber for turning the air stream from said refrigeration coil to direct it across said conveying means.   
     
     
       31. The apparatus as described in claim 30 wherein said circulating means are located in one corner of said second chamber and said turning vanes are located in and extend from the other three corners of said second chamber, each of said vanes extending substantially the length of said networks. 
     
     
       32. The apparatus as described in claim 31 wherein said conveying means is maintained in tension by tensioning means comprising a parallelogram linkage exerting a continuous force against the top sprocket in the network first receiving said top connecting strand and furthest from said driving means.