The present invention relates to the freezing of food products, and in particular, to a freezer that combines the techniques of plate freezing and impingement freezing.
Impingement freezers are well known in the art. Impingement freezers quickly freeze products by impinging refrigerated air onto the product which may be carried through the freezer on a conveyor belt. The impinged air may be directed onto the product by nozzles or by plates with perforations or channels for directing the air onto the product from above or below the product or both.
Plate freezers are also well known in the art. Plate freezers are typically used to freeze flat products or products packaged into flat packages or containers.
In some applications, both impingement freezers and plate freezers are employed which requires the dedication of valuable factory floor space for each separate freezer. It would be desirable to provide for both types of freezing in the same device to minimize the use of factory floor space.
The limitations of the prior art are overcome by the present invention as described below.
The present invention is directed to a device combining the techniques of plate freezing and impingement freezing. The device comprises one or more cooling modules disposed sequentially to obtain the degree of cooling required for a given application.
Each module comprises an enclosed insulated box. A continuous conveyor for carrying a food product runs through the sequence of insulated boxes. Each insulated box includes a refrigerated plate disposed underneath and supporting the conveyor. The refrigerated plate comprises an enclosed box through which a refrigerant, such as ammonia, runs. Each enclosed box is made of a suitable heat transfer material and is provided with a refrigerant inlet port and a refrigerant suction port. The inlet port and the suction port are operatively to connected to refrigeration equipment for refrigerating the refrigerant as known in the art.
The food product is simultaneously cooled using the impingement freezing technique. A cooling coil carrying a refrigerant is disposed within each insulated box above the conveyor. Each cooling coil is provided with a refrigerant inlet port and a refrigerant suction port. The inlet port and the suction port are operatively to connected to refrigeration equipment for refrigerating the refrigerant as known in the art. One or more fans are disposed below the cooling coil. Air within the insulated box is circulated downwardly through the cooling coil by the fans so that the air is cooled by the refrigerant.
An array of diverters is disposed below the fans so that the cooled air is forced to speed up in passing through the diverters. The high speed cooled air is then directed onto the food product disposed on the top of the conveyor using the impingement freezing technique.
The contact freezer may also comprise a pre-chilling section including the conveyor and refrigerated plate without the impingement freezing elements described above. The pre-chilling section is disposed in front of the first of the plurality of cooling modules. The pre-chilling section is not disposed within an insulated box. The food product is placed on the pre-chilling section where the cooling process is initiated and the food product is pre-chilled by the refrigerated plates disposed below the conveyor. The pre-chilled food product is then introduced to the cooling modules for freezing using both the plate freezing technique in combination with the impingement freezing technique.
These and other features, objects and advantages of the present invention will become better understood from a consideration of the following detailed description, appended claims and accompanying drawings where:
With reference to
Each contact freezer 10 may also include a pre-chilling section 12 located prior to any of the plurality of cooling modules 11 and an exit section 13 located subsequent to the last of the plurality of chilling modules 11. A continuous conveyor 14 runs along the length of the pre-chilling section 12, the plurality of cooling modules 11 and the exit section 13. Food products are placed on the pre-chilling section 12, pass through the plurality of cooling modules 11 and removed from the exit section 14. The conveyor 14 may be constructed and operated as would be well known in the art. For example, the conveyor 14 may be disposed on and around a series of rollers and may be driven by an electric drive motor.
As shown in
The food product transported through the cooling modules 11 is simultaneously cooled using both the plate freezing technique as described above and the impingement freezing technique. A cooling coil 19 carrying a refrigerant is disposed within each cooling module 11 above the conveyor 14. Each cooling coil 19 is provided with a refrigerant inlet port 20 and a refrigerant suction port 21. The inlet port 20 and the suction port 21 are operatively connected to refrigeration equipment (not shown) for refrigerating the refrigerant as known in the art. One or more fans 22 are disposed below the cooling coil 19. Air within the cooling module 11 is circulated downwardly through the cooling coil 19 by the fans 22 so that the air is cooled by the refrigerant.
An array of diverters 23 is disposed below the fans 22. The diverters define a plurality of narrow channels for passage of the air so that the cooled air is forced to speed up in passing through the array of diverters 23. The high speed cooled air is then directed onto the food product disposed on the top of the conveyor 14 so that the food product is cooled using the impingement freezing technique.
As shown in
After pre-chilling on the pre-chill section 12, the pre-chilled food product is then introduced to the cooling modules 11 for freezing using both the plate freezing technique in combination with the impingement freezing technique as described above.
The present invention combines the techniques of plate freezing and impingement freezing. One or more cooling modules disposed sequentially obtain the degree of cooling required for a given application. A continuous conveyor carries a food product through the sequence of cooling modules having a refrigerated plate disposed underneath and supporting the conveyor. The food product is simultaneously cooled using the impingement freezing technique in which high speed cooled air is directed onto the food product.
The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/628,984 filed Nov. 10, 2011, which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2012/059201 | 10/8/2012 | WO | 00 | 5/8/2014 |
Number | Date | Country | |
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61628984 | Nov 2011 | US |