WO2012099893A2

WO2012099893A2 - Impingement oven with a plurality of variable airflow cooking zones

Info

Publication number: WO2012099893A2
Application number: PCT/US2012/021580
Authority: WO
Inventors: Derek Allen WALZ; P. Andrew TYLER; Roberto Nevarez; Douglas S. Jones; Jan Claesson; Thomas Dailey
Original assignee: Lincoln Foodservice Products Llc
Priority date: 2011-01-17
Filing date: 2012-01-17
Publication date: 2012-07-26
Also published as: US20120180775A1; WO2012099893A3

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

IMPINGEMENT OVEN WITH A PLURALITY OF VARIABLE AIRFLOW

COOKING ZONES

FIELD OF THE DISCLOSURE

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

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. 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.

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.

There is a need to overcome the two challenges presented above.

SUMMARY OF THE DISCLOSURE

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. 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.

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. 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

In another embodiment of the cooking oven of the present disclosure, the processor executes the instructions to perform operations that comprise: enabling a user to enter the set of heat transfer rates via the user interface; and

operating the first and second independent air delivery systems according to the set of heat transfer rates to cook a food product.

In another embodiment of the cooking oven of the present disclosure, the operations further comprise:

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

operating the first and second independent air delivery systems according to the modified set of heat transfer rates to cook a food product.

storing the set of heat transfer rates in the memory.

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.

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: 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. In another embodiment of the method of the present disclosure, the processor executes the instructions to perform steps that comprise:

enabling a user to enter the set of heat transfer rates via the user interface; and

In another embodiment of the method of the present disclosure, the steps further comprise:

operating the first and second independent air delivery systems according to the modified set of heat transfer rates to cook a food product. In another embodiment of the method of the present disclosure, the steps further comprise: storing the set of heat transfer rates in the memory.

In another embodiment of the method of the present disclosure, the heat transfer rates are velocities of the first airflow and the second airflow.

In another embodiment of the method of the present disclosure, wherein the conveyor oven further comprises:

a third cooking zone located below the conveyor and beneath both of the first zone and the second zone; and

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.

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

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:

Fig. 1 is a front planar view of a multi-zone oven according to the present disclosure;

Fig. 2 is a schematic representation of a user interface of the multi- zone oven of Fig. 1 ;

Fig. 3 is a block diagram of a control system of the multi-zone oven of Fig. 1 ;

Fig. 4 is a block diagram of an independent air delivery system of the multi-zone oven of Fig. 1 ; and

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

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.

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.

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.

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. 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'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.

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.

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.

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.

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.

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. User interaction area 106 comprises a touch screen comprising a zone 1 box 108, a zone 2 box 1 10 and a zone 3 box 1 12. 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, 1 10 and 1 12. 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. 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.

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.

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. 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.

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.

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.

The conveyor oven of the present disclosure provides a flexibility that is achieved through the implementation of thee 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.

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. 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.

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.

Claims

WHAT IS CLAIMED IS:

1. A conveyor oven comprising:

a cooking chamber comprising an entry and an exit;

a conveyor extending through said cooking chamber between said entry and said exit;

a first cooking zone and a second cooking zone adjacent one another and above said conveyor;

a first independent air delivery system located to provide a first airflow and a second independent air delivery system to provide a second airflow to said first and second cooking zones, respectively; and

a control system comprising a processor, a memory, a program module disposed in said memory and a user interface, wherein said processor executes instructions of said program module to form a cooking profile that comprises a set of heat transfer rates for said first airflow and said second airflow based on interaction with said user interface.

2. The conveyor oven of claim 1 , further comprising:

a third cooking zone located below said conveyor and beneath both of said first zone and said second zone; and

a third independent air delivery system located to provide a third airflow to said third cooking zone, wherein said set of heat transfer rates further comprises a heat transfer rate for said third airflow.

3. The conveyor oven of claim 1 , wherein said cooking profile is selected from the group consisting of: new cooking profile and modified old cooking profile

4. The conveyor oven of claim 1 , wherein said processor executes said instructions to perform operations that comprise:

enabling a user to enter said set of heat transfer rates via said user interface; and

operating said first and second independent air delivery systems according to said set of heat transfer rates to cook a food product.

5. The conveyor oven of claim 4, wherein said operations further comprise:

enabling said user to enter a modified set of heat transfer rates that modify said set of heat rates to form a modified cooking profile; and

operating said first and second independent air delivery systems according to said modified set of heat transfer rates to cook a food product.

6. The conveyor oven of claim 4, wherein said operations further comprise:

storing said set of heat transfer rates in said memory.

7. The conveyor oven of claim 1 , wherein said heat transfer rates are velocities of said first airflow and said second airflow.

8. A method of operating a conveyor oven that comprises a conveyor extending through a cooking chamber, a first cooking zone and a second cooking zone adjacent one another and above said conveyor, a first independent air delivery system located to provide a first airflow and a second independent air delivery system to provide a second airflow to said first and second cooking zones, respectively, said method comprising:

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 said first airflow and said second airflow based on interaction with a user interface.

9. The method of claim 8, wherein said processor executes said instructions to perform steps that comprise:

10. The method of claim 9, wherein said steps further comprise:

1 1. The method of claim 9, wherein said steps further comprise:

storing said set of heat transfer rates in said memory.

12. The method of claim 8, wherein said heat transfer rates are velocities of said first airflow and said second airflow.

13. The method of claim 8, wherein said conveyor oven further comprises: a third cooking zone located below said conveyor and beneath both of said first zone and said second zone; and

14. The method of claim 8, wherein said cooking profile is selected from the group consisting of: new cooking profile and modified old cooking profile.