Abstract:
Conveyor oven that uses three or more cooking zones to provide flexible baking solutions in a commercial kitchen environment. The flexibility of each zone is achieved by providing variable air velocities in the impingement jets in each zone. By increasing or decreasing the air velocity in the zone the operator can control the heat transfer rate to the food product in that zone without having to actually adjust the temperature of the oven. The airflow rate in the zones is controlled via the operator controller.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority of U.S. Provisional Application No. 61/433,506, filed Jan. 17, 2011, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure generally relates to an impingement conveyor oven and method that provides flexible baking solutions in a commercial kitchen environment. 
       BACKGROUND OF THE DISCLOSURE 
       [0003]    Conveyor ovens have historically been known for their consistency in baking large volumes of the same food over and over with little interaction from the operator. This is something that has historically made conveyor ovens a good option for pizza chains. However, for restaurants with larger menus that require flexible cooking options, the conveyor oven has not always been the best option. The need for flexibility may drive the user to implement a batch oven of sorts to allow for more rapid changes to the cook settings such as; time, temperature, microwave percentage (%), convection %, etc. 
         [0004]    Current commercial conveyor ovens use primarily impingement air to provide heat transfer to the food product. Traditionally, the air is delivered via a mechanical ductwork (commonly known as a finger) on the top and bottom of the food as it passes through the oven on a conveyor. These mechanical fingers have had a multitude of designs and configurations to achieve custom specific cooking solutions over the years. The shape and design of the air nozzles can be manipulated to vary the heat transfer rates in respective zones in the oven. However, once the fingers are developed and installed, their designs are static. There is no ability to change or adapt the oven to future menu items or changes to your menu items, other than to go through the iterative process of developing new mechanical air ducts. Each time a new cooking solution is desired extensive development work is required to design and validate the optimum finger configuration in the oven. This development time is common in the conveyor industry and this challenge has not been overcome in the designs that are currently on the market. Not only does this development time cost the company resource and prototype expenses, it also may lead to lost sales as customers are able to find other solutions to their needs in a more timely manner. 
         [0005]    The second major challenge within the conveyor oven market is its perception as a non-flexible piece of equipment that is not able to be quickly configured to cook food items that require varying temperature and/or time settings to achieve the optimum results. For example, if a customer wanted to cook a pizza followed by a piece of chicken breast, the temperature and time settings of the oven must be altered. Then it will take ten minutes or more for the oven to recalibrate to the appropriate temperature. 
         [0006]    There is a need to overcome the two challenges presented above. 
       SUMMARY OF THE DISCLOSURE 
       [0007]    The conveyor oven of the present disclosure overcomes the above noted challenges by dividing the conveyor oven into independent cooking zones. Flexibility of each zone is achieved by providing variable air velocities in the impingement jets in each zone. The division of the conveyor oven into zones with variable speed airflow allows the heat transfer rate to the food to be adjusted to the upper and lower limits without actually adjusting the temperature of the oven. By not having to change the oven temperature the change in heat transfer rate can be virtually instantaneous as the air velocity is increased or decreased via a change in fan speed. This has shown to greatly reduce the development period required to achieve new cooking solutions because many more tests can be run in a short period of time. There is no need to fabricate and test new finger panels as the same results can be achieved through varying the airflow rate through the existing fingers. It also allows for greater control over the cooking process by allowing the oven to provide different heat transfer rates to the food at various phases of the cooking process. This solution provides a level of innovation and flexibility that has not been present in the conveyor oven market to date. 
         [0008]    In one embodiment of a conveyor oven of the present disclosure, a cooking chamber comprises an entry and an exit. A conveyor extends through the cooking chamber between the entry and the exit. A first cooking zone and a second cooking zone are located adjacent one another and above the conveyor. A first independent air delivery system is located to provide a first airflow and a second independent air delivery system is located to provide a second airflow to the first and second cooking zones, respectively. A control system comprises a processor, a memory, and a program module disposed in the memory and a user interface. The processor executes instructions of the program module to form a cooking profile that comprises a set of heat transfer rates for the first airflow and the second airflow based on interaction with the user interface. 
         [0009]    In another embodiment of the cooking oven of the present disclosure, a third cooking zone is located below the conveyor and beneath both of the first zone and the second zone. A third independent air delivery system is located to provide a third airflow to the third cooking zone. The set of heat transfer rates further comprises a heat transfer rate for the third airflow. 
         [0010]    In another embodiment of the cooking oven of the present disclosure, the cooking profile is selected from the group consisting of: new cooking profile and modified old cooking profile 
         [0011]    In another embodiment of the cooking oven of the present disclosure, the processor executes the instructions to perform operations that comprise: 
         [0012]    enabling a user to enter the set of heat transfer rates via the user interface; and 
         [0013]    operating the first and second independent air delivery systems according to the set of heat transfer rates to cook a food product. 
         [0014]    In another embodiment of the cooking oven of the present disclosure, the operations further comprise: 
         [0015]    enabling the user to enter a modified set of heat transfer rates that modify the set of heat rates to form a modified cooking profile; and 
         [0016]    operating the first and second independent air delivery systems according to the modified set of heat transfer rates to cook a food product. 
         [0017]    In another embodiment of the cooking oven of the present disclosure, the operations further comprise: 
         [0018]    storing the set of heat transfer rates in the memory. 
         [0019]    In another embodiment of the cooking oven of the present disclosure, the heat transfer rates are velocities of the first airflow and the second airflow. 
         [0020]    In one embodiment of a method of the present disclosure, the method operates a conveyor oven that comprises a conveyor extending through a cooking chamber. A first cooking zone and a second cooking zone are located adjacent one another and above the conveyor. A first independent air delivery system is located to provide a first airflow and a second independent air delivery is located to provide a second airflow to the first and second cooking zones, respectively. The method comprises: 
         [0021]    using a processor to execute instructions of a program to form a cooking profile for a food product that comprises a set of heat transfer rates for the first airflow and the second airflow based on interaction with a user interface. 
         [0022]    In another embodiment of the method of the present disclosure, the processor executes the instructions to perform steps that comprise: 
         [0023]    enabling a user to enter the set of heat transfer rates via the user interface; and 
         [0024]    operating the first and second independent air delivery systems according to the set of heat transfer rates to cook a food product. 
         [0025]    In another embodiment of the method of the present disclosure, the steps further comprise: 
         [0026]    enabling the user to enter a modified set of heat transfer rates that modify the set of heat rates to form a modified cooking profile; and 
         [0027]    operating the first and second independent air delivery systems according to the modified set of heat transfer rates to cook a food product. 
         [0028]    In another embodiment of the method of the present disclosure, the steps further comprise: storing the set of heat transfer rates in the memory. 
         [0029]    In another embodiment of the method of the present disclosure, the heat transfer rates are velocities of the first airflow and the second airflow. 
         [0030]    In another embodiment of the method of the present disclosure, wherein the conveyor oven further comprises: 
         [0031]    a third cooking zone located below the conveyor and beneath both of the first zone and the second zone; and 
         [0032]    a third independent air delivery system located to provide a third airflow to the third cooking zone, wherein the set of heat transfer rates further comprises a heat transfer rate for the third airflow. 
         [0033]    In another embodiment of the method of the present disclosure, the cooking profile is selected from the group consisting of: new cooking profile and modified old cooking profile 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    Other and further objects, advantages and features of the present disclosure will be understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference characters denote like elements of structure and: 
           [0035]      FIG. 1  is a front planar view of a multi-zone oven according to the present disclosure; 
           [0036]      FIG. 2  is a schematic representation of a user interface of the multi-zone oven of  FIG. 1 ; 
           [0037]      FIG. 3  is a block diagram of a control system of the multi-zone oven of  FIG. 1 ; 
           [0038]      FIG. 4  is a block diagram of an independent air delivery system of the multi-zone oven of  FIG. 1 ; and 
           [0039]      FIG. 5  is a flow diagram for a cooking zone of a program module of the control system of  FIG. 3 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0040]    Referring to  FIG. 1 , an impingement conveyor oven  20  of the present disclosure comprises a cooking chamber  22  that includes a right hand opening  23  and a left hand opening  25 . A conveyor  24  extends horizontally through cooking chamber  22  between right hand opening  23  and left hand opening  25 . For the purpose of the embodiment shown in  FIG. 1 , right hand opening  23  and left hand opening  25  are considered as exit and entry openings, respectively. In other embodiments left hand opening  25  may be the exit and right hand opening  23  may be the entry. 
         [0041]    Three or more independent cooking zones  26 ,  28  and  30  are defined within cooking chamber  22 . By way of example, three independent cooking zones  26 ,  28  and  30  are shown in the embodiment of  FIG. 1 . Cooking zones  26  and  28  are located above conveyor  24  and adjacent one another or side by side along the horizontal length or travel direction of conveyor  24 . Independent cooking zone  30  is located below conveyor  24  and extends along the horizontal length of conveyor  24 . In other embodiments, there may be more than two independent cooking zones above conveyor  24 . In still other embodiments, there may be more than one cooking zone below conveyor  24 . 
         [0042]    One or more jet fingers are located in each cooking zone  26 ,  28  and  30 . In the embodiment of  FIG. 1 , two jet fingers  32  and  34  are located in cooking zone  26 . Two jet fingers  28  and  30  are located in cooking zone  28 . Four jet fingers  40 ,  42 ,  44  and  46  are located in cooking zone  30 . Jet fingers  32 ,  34 ,  36 ,  38 ,  40 ,  42 ,  44  and  46  each comprises a jet plate  50 , which has a plurality of jet apertures (not shown) that convert a circulating air flow to impingement columns or jets of airflow toward conveyor  24 . A user interface  82  is disposed on a suitable location of impingement conveyor oven  20 . 
         [0043]    Referring to  FIGS. 1 and 4 , each zone  26 ,  28  and  30  has its own independent air delivery system  60 . Since the air delivery systems  60  are similar for each cooking zone, air delivery system  60  will be described in detail only for cooking zone  26 . As shown in  FIG. 4 , air delivery system  60  comprises a ductwork  62  that is disposed to take in airflow from above conveyor  24  in cooking zone  26  and to return airflow to jet fingers  32  and  34 . A heating device (not shown) heats the airflow in ductwork  62 . A fan or blower  64  is disposed in ductwork  62  to provide a circulating airflow. A motor  66  is coupled to drive fan  64 . A signal conditioner  68  has an input from an AC source  70  and an output that supplies operating current to motor  66 . Motor  66  can be any suitable motor for driving fan  64  according to the system described in this disclosure. Preferably, motor  66  is a variable speed AC motor. 
         [0044]    Signal conditioner  68  varies the speed or rpm of motor  66 , which in turn varies the speed of fan  64  to provide rapid changes in velocity of the airflow in zone  26 . A change in airflow velocity results in a change in heat transfer rate to the food on conveyor  24 . As the motor speed changes very rapidly, the fan speed and airflow velocity is also changed rapidly. The operator can establish a preferred % of airflow for each of the zones via a control system  80  (shown in  FIG. 3 ). Control system  80  then sends a signal to signal conditioner  68 , which in turn appropriately increases or decreases the speed or rpm&#39;s of the motor  66  for that particular zone. Lower airflow limits are established based on the requirements of keeping clean combustion within the oven. The flexibility achieved through having a conveyor oven with three or more independent cooking zones allows for rapid configuration of the oven for new or modified old cooking profiles without changing the cooking temperature, thus expanding the use of conveyor oven  20  in the industry. 
         [0045]    Referring to  FIG. 3 , impingement oven  20  further comprises control system  80 . Control system  80  is coupled to a network  90 , e.g., a local network or a global network, e.g., the Internet. Control system  80  may be coupled via network  90  to other devices such as a storage medium  92 . 
         [0046]    Control system  80  comprises user interface  82 , a processor  84 , and a memory  86 . Processor  84  and memory  86  may be implemented on a general-purpose microcomputer. Memory  86  stores data and instructions used by processor  84  to control the operation of impingement oven  20 . Memory  80  may be implemented in a random access memory (RAM), a hard drive, a read only memory (ROM), or a combination thereof. A program module  88  is stored in memory  86 . 
         [0047]    Program module  88  contains instructions that processor  84  executes to control the operation of impingement oven  20  and to implement entered cooking profiles and changes to existing cooking profiles entered by the user. The term “module” is used herein to denote a functional operation that may be embodied either as a stand-alone component or as an integrated configuration of a plurality of sub-ordinate components. Thus, program module  88  may be implemented as a single module or as a plurality of modules that operate in cooperation with one another. Moreover, although program module  88  is described herein as being installed in memory  86  and, therefore, being implemented in software, it could be implemented in any of hardware (e.g., electronic circuitry), firmware, software, or a combination thereof. 
         [0048]    User interface  82  in some embodiments includes an input device, such as a keyboard or speech recognition subsystem, for enabling a user to communicate information and command selections to processor  84 . User interface  82  also includes an output device such as a display or a printer. A cursor control such as a mouse, track-ball, or joy stick, allows the user to manipulate a cursor on the display for communicating additional information and command selections to processor  84 . 
         [0049]    It will be appreciated that user interface  82  can be of any design and structure that allows a user to input a cooking profile to processor  84 . By way of example, and completeness of description, user interface  82  is shown in  FIG. 2  as comprising a display  100  that includes a screen  104 . Screen  104  comprises a banner  100  and a user interaction area  106 . Banner  100  includes information pertinent to screen  100 . For example, banner  100  includes an identification of the screen type, i.e., Manual Mode. Manual Mode is highlighted (e.g., in bold face) to indicate that screen  100  is part of a user inactive session with processor  84  and program module  88 . 
         [0050]    User interaction area  106  comprises a touch screen comprising a zone  1  box  108 , a zone  2  box  110  and a zone  3  box  112 . Each box includes the message, 100% that indicates an airflow of 100% velocity. In Manual Mode, the user can use a finger with a tapping or sliding motion, for example, to enter a different % velocity in any one or more of boxes  108 ,  110  and  112 . For example, if a cook profile has 100% air velocity in all three zones, the user can reduce the % velocity in zone  2  to 50% air velocity. 
         [0051]    Processor  84  outputs to user interface  82  a result (new cooking profile or modified old cooking profile) of an execution of the methods described herein. Alternatively, processor  84  could direct the output to a remote device (not shown) via network  90 . 
         [0052]    Processor  84  executes the instructions of program module  88  to form a cooking profile that comprises a set of heat transfer rates for the first airflow for cooking zone  26 , second airflow for cooking zone  28  and third airflow for cooking zone  30  based on interaction with user interface  82 . In addition, the executed instructions perform the steps of:
       enabling a user to enter the set of heat transfer rates via user interface  82 ;   operating the first, second and third independent air delivery systems  60  according to the set of heat transfer rates to cook a food product; enabling the user to enter a modified set of heat transfer rates that modify the set of heat rates to form a modified cooking profile;   operating first, second and third independent air delivery systems  60  according to the modified set of heat transfer rates to cook a food product; and   storing set of heat rates in a memory.       
 
         [0057]    As the programmed operation is the same for cooking zones  26 ,  28 , and  30 , there is shown in  FIG. 5  a top level flow diagram for one of the cooking zones, for example cooking zone  26 . Program module  88  at box  120  provides instructions, which processor  84  executes to initiate operation of air delivery system  60  of cooking zone  26 . Program module at box  122  provides instructions that processor  84  executes to read from memory  86  the set of heat transfer rates for cooking zone  26 . For the embodiment of conveyor oven  20  illustrated herein, the heat transfer rates are expressed as a % velocity. Processor  84  executes the instructions of box  124  to convert the % velocity values to a signal that is supplied by connectors not shown to signal conditioner  68  of air delivery system  60  of cooking zone  26 . Processor  84  executes the instructions of box  126  to determine if fan  64  of air delivery system  60  of cooking zone  26  is set properly. If not, processor  84  provides an error message to user interface  82 . 
         [0058]    If fan  60  is set properly, processor  84  executes the instructions of box  130  to determine if control system  80  is in manual mode. If not, processor  64  executes the instructions for box  136  to operate air delivery system  60  for cooking zone  26  to provide a heated airflow having a velocity that corresponds to the set point value in the set point data retrieved from memory  86 . 
         [0059]    If processor  84  determines that control system  80  is in manual mode, processor  84  executes instructions of box  134  to determine if the set point data is changed. That is, processor  84  determines if there has been a change to the set of heat transfer rates at user interface  82 . If not, processor  64  executes the instructions for box  136  to operate air delivery system  60  for cooking zone  26  to provide a heated airflow having a velocity that corresponds to the set point value in the set point data retrieved from memory  86  for a time duration according to a currently running cooking profile. If yes, processor  84  executes the instructions of box  138  to obtain new set point data from user interface  82 . This newly obtained set point data is then used by processor  84  to again execute the instructions of box  124  to convert the % velocity values of the new set point data to a signal that is supplied by connectors not shown to the signal conditioner  68  for cooking zone  26 . Processor  84  then repeats the execution of instructions of boxes  130 ,  134 ,  136  and/or  138 . 
         [0060]    While program module  88  is indicated as already loaded into memory  86 , it may be configured on storage medium  92  for subsequent loading into memory  86 . Storage medium  92  can be any storage medium that stores program module  88  in tangible form. Examples of storage medium  92  include a floppy disk, a compact disk, a magnetic tape, a read only memory, an optical storage media, universal serial bus (USB) flash drive, a digital versatile disc, a zip drive or other storage device. Alternatively, storage medium  92  can be a random access memory, or other type of electronic storage, located on a remote storage system and coupled to control system  80  via network  90 . 
         [0061]    The conveyor oven of the present disclosure provides a flexibility that is achieved through the implementation of three or more cooking zones. Each cooking zone has the ability to independently control the airflow velocity in that zone. The airflow velocity directly correlates to h value (heat transfer coefficient) that is applied to the food. The preferred embodiment of a multi-zone conveyor oven would have two or more cooking zones on top of the conveyor and one or more cooking zones on the bottom. The reason for this distinction comes down to the ability of the food product to accept heat from the top and bottom surfaces of the food. Typical foods that are cooked on a conveyor oven are carried in some type of metallic carrier that reduces the need to have flexible heat transfer rates on the bottom of the food. However, the top surface of the food is able to accept heat at varying levels throughout the cooking process. As the food passes through the oven from right to left or left to right, in order to optimally cook the food, one must have the ability to vary the heat transfer rate to that top surface. At the beginning of the cooking process, the food may be able to accept a high level of heat, while at the end of the process, the food may not be able to accept this same level of heat without having adverse affects such as; over caramelizing, crisping, charring, or discoloring. 
         [0062]    Traditionally this is solved in a conveyor oven, by the use of mechanical fingers or air ducts. The shape and design of the air nozzles can be manipulated to vary the heat transfer rates in respective zones in the oven. However, once the fingers are developed and installed, their designs are static. There is no ability to change or adapt your oven to future menu items or changes to your menu items, other than to go through the iterative process of developing new mechanical air ducts. 
         [0063]    The conveyor oven of the present disclosure provides a step change in the conveyor cooking process because it allows the user to manipulate the heat transfer rate in multiple cooking zones via a user interface control. The time needed for new menu items to be developed is drastically reduced as culinary personnel have the ability to perform multiple iterations of testing in a matter of hours, instead of the cumbersome trial and error process that takes weeks and months today. It will also allow for multiple food product types to be cooked one right after the other in a conveyor application without a need to change the temperature or belt speed of the oven. Merely manipulating the airflow zones will provide adequate flexibility to cook a wide variety of food products. 
         [0064]    The present disclosure having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present disclosure as defined in the appended claims.