Abstract:
An oven has a first conveyor, a first burner that directs heat toward the first conveyor from above the first conveyor, and a second burner that directs heat toward the first conveyor from below the first conveyor. A method includes providing foodstuff on a conveyor, exposing the foodstuff to heat directed toward the foodstuff from above the conveyor, and exposing the foodstuff to heat directed toward the foodstuff from below the conveyor. Another oven has a first conveyor and first conveyor insulators that surround the first conveyor and define a first zone. Another method includes introducing foodstuff to a first conveyor belt within a first insulated zone, introducing heat into the first insulated zone, and retaining a portion of the heat within the first insulated zone. Another oven has an insulated cooking zone that closely envelopes a cooking path and an insulated oven zone that substantially envelopes the cooking zone.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/903,839, filed May 28, 2013, by Souhel Khanania entitled, “Oven”, which is a continuation of U.S. Pat. No. 8,448,568 issued on May 28, 2013 entitled, “Oven”, which is a continuation of U.S. Pat. No. 8,201,493 issued on Jun. 19, 2012, entitled, “Oven”, which claims priority to U.S. Provisional Patent Application No. 61/018,830 filed on Jan. 3, 2008, all of which are incorporated by reference herein as if reproduced in their entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO A MICROFICHE APPENDIX 
       [0003]    Not applicable. 
       BACKGROUND 
       [0004]    Large quantities of energy are used in the manufacture of modern food products. Systems and methods that can reduce the total energy consumption of manufacturing plants that create, package, and prepare the food would be beneficial. Therefore systems and methods that provide for the efficient manufacture of food products are desirable. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    In some embodiments, an oven is disclosed as comprising: a first conveyor disposed in a first zone at least partially vertically below a first insulator, at least partially vertically above a second insulator, and at least partially between a first side insulator and an opposing second side insulator; a second conveyor disposed at least partially vertically below the first conveyor and in a second zone at least partially vertically below a third insulator and at least partially vertically above a fourth insulator, wherein at least a portion of the second insulator is vertically above the third insulator, and wherein at least a portion of the third insulator is vertically above the fourth insulator; and an insulated duct that connects the first zone to the second zone and that is formed by disposing the first side insulator and the opposing second side insulator at least partially vertically between the first insulator and the third insulator; wherein the insulated duct provides a flowpath for heat to pass from the second zone to the first zone; and wherein the first conveyor moves foodstuff on the first conveyor from the first zone onto the second conveyor in the second zone. 
         [0006]    In other embodiments, a method of operating an oven is disclosed as comprising: providing a first conveyor in a first zone at least partially vertically below a first insulator, at least partially vertically above a second insulator, and at least partially between a first side insulator and an opposing second side insulator; providing a second conveyor at least partially vertically below the first conveyor and in a second zone at least partially vertically below a third insulator and at least partially vertically above a fourth insulator, wherein at least a portion of the second insulator is vertically above the third insulator, and wherein at least a portion of the third insulator is vertically above the fourth insulator; providing an insulated duct that connects the first zone to the second zone and that is formed by disposing the first side insulator and the opposing second side insulator at least partially vertically between the first insulator and the third insulator; passing heat through the insulated duct from the second zone to the first zone; and operating the first conveyor to move foodstuff on the first conveyor from the first zone onto the second conveyor in the second zone. 
         [0007]    The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments of the disclosure, and by referring to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. 
           [0009]      FIG. 1  is an oblique view of an oven according to the present disclosure; 
           [0010]      FIG. 2  is a front view of the oven of  FIG. 1 ; 
           [0011]      FIG. 3  is an enlarged oblique view of a portion of the upper right side of the oven of  FIG. 1 ; 
           [0012]      FIG. 4  is an enlarged oblique view of a portion of the lower left side of the oven of  FIG. 1 ; 
           [0013]      FIG. 5  is an oblique view of the belts and IR burners of the oven of  FIG. 1 ; 
           [0014]      FIG. 6  is an upper oblique view of the belts and cooking zone of the oven of  FIG. 1 ; 
           [0015]      FIG. 7  is a lower oblique view of the belts and cooking zone of the oven of  FIG. 1 ; 
           [0016]      FIG. 8  is an enlarged oblique view of the left side of the belts and cooking zone of the oven of  FIG. 1 ; 
           [0017]      FIG. 9  is an enlarged oblique view of the right side of the belts and cooking zone of the oven of  FIG. 1 ; 
           [0018]      FIG. 10  is a front oblique view of the frame and air delivery system of the oven of  FIG. 1 ; 
           [0019]      FIG. 11  is an oblique view of a mixer of the oven of  FIG. 1 ; 
           [0020]      FIG. 12  is an oblique view of an IR burner of the oven of  FIG. 1 ; 
           [0021]      FIG. 13  is an oblique upper view of a belt guide of the oven of  FIG. 1 ; 
           [0022]      FIG. 14  is an oblique front view of two belt tensioners of the oven of  FIG. 1 ; 
           [0023]      FIG. 15  is an oblique view of a motor, gearbox, and drive shaft of the oven of  FIG. 1 ; 
           [0024]      FIG. 16  is a simplified front view of another oven according to the present disclosure; and 
           [0025]      FIG. 17  is a simplified front view of still another oven according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In the preparation of food materials, such as, but not limited to, potato, corn, and tortilla chips, cooking the foodstuff sometimes consumes large quantities of energy. Conventional industrial ovens lose a significant amount of heat and energy due to poor design and/or a lack of insulation. Systems and methods that could improve on the efficiency of ovens would greatly reduce the overall energy required to manufacture foodstuff. Accordingly, the present disclosure discloses systems and methods that may be implemented to reduce energy consumption in the process of cooking foodstuff. 
         [0027]    Typical ovens comprise large enclosures having multiple conveyors within the enclosures. Sometimes the multiple conveyors work together to form a path along which foodstuff successively travels from one conveyor to the next. However, the typical ovens require that the entire enclosure be heated in order to cook foodstuff on the conveyors, thereby unnecessarily heating the contents of space that is not in close proximity or adjacent to the foodstuff. The unnecessary heating of the contents of a large volume of space accounts for a large amount of energy consumption and waste, rendering the cooking process unnecessarily energy inefficient. 
         [0028]    The present disclosure provides for substantially enclosing each conveyor within substantially adjacent insulative barriers that generally serve to envelope the conveyors individually within zones. The present disclosure further discloses providing insulated ducts for connecting the various zones that relate to the conveyors so that heat is efficiently transferred between the various zones. The present disclosure provides a cooking zone that comprises the zones that are individually related to the conveyors and further comprises the insulated ducts that join the various zones. Generally, the insulative barriers serve to retain heat within the cooking zone, thereby allowing more efficient cooking of foodstuff within the cooking zone. The present disclosure further provides gas-fueled infrared burners positioned to emit and direct heat toward one or more conveyors from both above the conveyors and from below the conveyors. Still further, the present disclosure provides enclosing the cooking zone within an oven zone that substantially envelops the entirety of the cooking zone so that heat loss from the cooking zone is reduced. While every combination is not discussed, the present disclosure expressly contemplates combining the disclosed features in many combinations. For example, an oven according to the disclosure may comprise one or more conveyors that are enclosed by insulative barriers and one or more of those conveyors may have infrared burners associated with the conveyor to emit and direct heat on the conveyor from both above and below the conveyors. 
         [0029]    Referring now to  FIGS. 1-4 , an oven  100  is disclosed. Oven  100  comprises a supportive frame  102  having a plurality of structural components, only some of which are described in greater detail below. The frame  102  is supported by feet  104  attached to the bottom of the frame  102 . The oven  100  has a left side shown generally leftward in  FIG. 2  and a right side shown generally rightward in  FIG. 2 . Further, the oven  100  has a front side that is displayed generally between the left and right sides in  FIG. 2 . Accordingly, the oven  100  comprises a top side opposite the bottom side and a rear side opposite the front side. It will be appreciated that the above directional conventions apply throughout the description of oven  100 . 
         [0030]    Most generally, the oven  100  comprises an upper conveyor system  106 , a middle conveyer system  108 , and a lower conveyor system  110 . Each of the conveyor systems  106 ,  108 ,  110  comprise the necessary equipment for operation of each conveyor system  106 ,  108 ,  110  independent of the others. In the preferred embodiment, each conveyor system  106 ,  108 ,  110  comprises its own motor  112 , gearbox  114 , drive shaft  116 , and belt tensioners  118 . It will be appreciated that in other embodiments, a single motor may be used to power one or more conveyors. Each conveyor system  106 ,  108 ,  110  further comprises the necessary drive drums  120 , tensioner drums  122 , and free drums  124  to carry conveyor belts. The conveyor systems  106 ,  108 ,  110 , together, generally define a cooking path along which foodstuff is carried and cooked while present on the cooking path. 
         [0031]    At an entrance  126  formed by the frame  102  (most clearly shown in  FIG. 3 ), foodstuff may be introduced to an upper surface of an upper belt  128 . The upper conveyor system  106  operates to rotate upper belt  128  in a generally counterclockwise direction as viewed in  FIG. 2  so that the upper surface of upper belt  128  moves from right to left. Middle conveyor system  108  is located generally below upper conveyor system  106  so that as foodstuff reaches the left end of the upper belt  128 , the foodstuff falls from the upper belt  128  to an upper surface of a middle belt  130  of middle conveyor system  108 . The middle conveyor system  108  operates to rotate middle belt  130  in a generally clockwise direction as viewed in  FIG. 2  so that the upper surface of middle belt  130  moves from left to right. 
         [0032]    Lower conveyor system  110  is located generally below middle conveyor system  108  so that as foodstuff reaches the right end of the middle belt  130 , the foodstuff falls from the middle belt  130  to an upper surface of a lower belt  132  of lower conveyor system  110 . The lower conveyor system  110  operates to rotate lower belt  132  in a counterclockwise direction as viewed in  FIG. 2  so that the upper surface of lower belt  132  moves from right to left. As foodstuff reaches the left end of the lower belt  132  the foodstuff is free to fall from lower belt  132  down through an exit  134  formed generally by the frame  102  (most clearly shown in  FIG. 4 ). In some embodiments the oven  100  may be associated with other foodstuff preparation and/or packaging equipment so that once foodstuff passes through exit  134  the foodstuff is collected and is further processed and/or packaged. It will be appreciated that, in this embodiment, the cooking path of foodstuff is defined as the path along which foodstuff travels within the oven  100  (i.e. along the conveyor belts  128 ,  130 ,  132  as described above). 
         [0033]    The cooking path is more than a path along which foodstuff is moved. The cooking path is a path along which foodstuff is cooked by exposure to high temperatures through various forms of heat transfer as discussed below. In this embodiment, each conveyor system  106 ,  108 ,  110  has a plurality of gas fueled infrared burners  136  (see  FIGS. 5 and 12 ) (hereinafter referred to as “IR burners”) associated therewith. The IR burners  136  are fed a mixture of air and fuel gas through mixers  138  that are described in greater detail below (see  FIG. 11 ). While IR burners  136  are not shown in  FIGS. 1-4 , it will be appreciated that one IR burner  136  is associated with each mixer  138 . As described in more detail below, each IR burner  136  is capable of directing radiant heat in a directional manner. 
         [0034]    Referring now to  FIG. 5 , the upper, middle, and lower belts  128 ,  130 , and  132  are shown along with the IR burners  136 , but without the remainder of the components of the oven  100 . In this embodiment, the upper belt  128  is associated with six IR burners  136  that are located slightly above the upper belt  128  and that are oriented to emit radiant heat downward onto upper belt  128 . The upper belt  128  is further associated with six IR burners  136  that are located slightly below the upper belt  128  and that are oriented to emit radiant heat upward onto upper belt  128 . Similarly, middle belt  130  is associated with six IR burners  136  that are located slightly below the middle belt  130  and that are oriented to emit radiant heat upward onto middle belt  130 . Finally, lower belt  132  is associated with eight IR burners  136  that are located slightly below the lower belt  132  and that are oriented to emit radiant heat upward onto the lower belt  132 . Of course, in alternative embodiments, an upper belt may comprise IR burners only above or below the upper belt, a middle belt may comprise IR burners both above and below the middle belt or may comprise IR burners only above the middle belt, and a lower belt may comprise IR burners both above and below the middle belt or may comprise IR burners only above the lower belt. Also, burners other than IR burners may be used or used in combination with IR burners. 
         [0035]    A feature of the oven  100  is that heat generated by IR burners  136  is not merely cast upon the belts  128 ,  130 ,  132  and easily allowed to pass into the general interior space of the oven  100  (where the interior space is generally defined by the left, right, bottom, top, front, and rear of the oven  100 ), but rather, the heat is retained near the foodstuff. Specifically, the oven  100  is constructed in a manner that substantially encloses the cooking path in a minimal envelope of space, thereby retaining the heat generated by the IR burners  136  in space near the foodstuff that is carried along the cooking path. Most generally, the heat is retained by constructing insulative barriers to prevent the escape of heat so that the cooking path (i.e. each conveyor belt  128 ,  130 ,  132 ) is substantially enclosed within an insulated cooking zone. 
         [0036]    Referring now to  FIGS. 6-9 , the insulated cooking zone is defined generally as a substantially contiguous space that is substantially bounded by insulation in close proximity to the cooking path. In this embodiment, an upper zone substantially surrounds the upper belt  128  and is defined generally by the space bounded by upper insulators  140 , lower insulators  142 , left insulators  144 , right insulators  146 , front insulators  148 , and rear insulators  150 . The various insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150  are generally plate-like in shape and serve to closely bound the belts  128 ,  130 ,  132  while being sized and/or otherwise shaped to accommodate protrusions of other portions of the oven  100  as necessary. In keeping with the goal of substantially enclosing the cooking path within a cooking zone, the insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150  generally form substantially continuous walls around the belts  128 ,  130 ,  132 . However, upper burner openings  152  and lower burner openings  154  are present to allow a passage for radiant heat to enter the cooking zone from IR burners  136 . The insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150  also form a middle zone that substantially surrounds the middle belt  130  and a lower zone that substantially surrounds the lower belt  132 . 
         [0037]    It will further be appreciated that the upper, middle, and lower zones are connected to generally form the single cooking zone. Specifically, the insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150  form a right duct  156  that generally connects the right side of the lower zone to the right side of the middle zone. The insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150  also generally form a left duct  158  that generally connects the left side of the middle zone to the left side of the upper zone. The joint nature of the lower, middle, and upper zones allow heat and hot air to travel in a directed manner from left to right in the lower zone, up through the right duct  156 , from right to left in the middle zone, up through the left duct  158 , and finally from left to right in the upper zone. The heat and hot air in the cooking zone generally travels along a path opposite in direction to the direction the foodstuff is carried along the cooking path. 
         [0038]    By directing the heat and hot air in the manner described above, the heat generated by IR burners  136  associated with the lower belt  132  that is not absorbed by foodstuff on the lower belt  132  is not lost. Instead, the unabsorbed heat encounters foodstuff along the entire length of the cooking path until the heat is ultimately fully absorbed by foodstuff along the cooking path or the heat exits the cooking zone near the right side of the upper zone. It will be appreciated that front insulators  148  that aid in forming the right duct  156  and left duct  158  are omitted from view in  FIGS. 8 and 9  to allow a view inside the right duct  156  and the left duct  158 . 
         [0039]    Referring again to  FIGS. 1-4 , the oven  100  further comprises an insulated oven zone that is generally defined by outer insulators  160  that bound the oven zone. The oven zone substantially envelopes the cooking zone so that any heat escaping the cooking zone within the oven  100  is retained within the oven zone. It will be appreciated that while outer insulators  160  are mostly shown as being associated with the top and bottom sides of the oven  100 , outer insulators  160  associated with the right, left, front, and rear sides of the oven  100  are expressly contemplated by this disclosure. Some outer insulators  160  associated with the right, left, front, and rear sides of the oven  100  are not shown in order to provide clarity in view of the other components of the oven  100 . 
         [0040]    The effect of providing an insulated oven zone is that temperature gradients at the interface of the cooking zone and the oven zone are less than what the temperature gradients would be between the cooking zone and an otherwise existing adjacent ambient zone. Since the temperature gradient between the cooking zone and the next adjacent zone is lessened, a lower amount of heat transfer will occur between the cooking zone and the next adjacent zone. In other words, with the provision of the oven zone, heat will tend to transfer away from the cooking zone at a reduced rate. Further, an exhaust heat duct  162  is provided that is shown as a substantially rectangular structure and that connects the oven zone to another space. In some embodiments, the exhaust heat duct  162  may direct exhaust heat to the exterior of a building that houses the oven  100 . In other embodiments, the exhaust heat duct  162  may direct heat to another device or zone to allow recapture and/or reuse of the exhausted heat. 
         [0041]    Referring now to  FIG. 10 , a simplified view of the frame  102  is shown to illustrate that the frame  102  serves not only as a structural support system, but also as an air delivery system. Specifically, frame  102  comprises an air input manifold  164  that supplies air to top burner upper manifolds  166  that supply air to IR burners  136  that direct heat downward onto upper belt  128 . Similarly, frame  102  comprises supply air to bottom burner upper manifolds  168  that supply air to IR burners  136  that direct heat upward onto upper belt  128 . Further, frame  102  comprises middle manifolds  170  that supply air to the IR burners  136  that direct heat upward onto middle belt  130 . Finally, frame  102  comprises lower manifolds  172  that supply air to the IR burners  136  that direct heat upward onto lower belt  132 . Each manifold  166 ,  168 ,  170 ,  172  has a plurality of mixers  138  attached thereto and the mixers  138  serve as outlets for air supplied through the manifolds  166 ,  168 ,  170 ,  172 . 
         [0042]    Referring now to  FIG. 11 , a mixer  138  is shown. The mixer  138  comprises a latch  174  for securing mixer  138  to one of the previously described manifolds  166 ,  168 ,  170 ,  172 . The mixer  138  further comprises a gas inlet  176  for attachment to a gas supply line. The mixer  138  also comprises a gas adjustment  178  that functions to alter the flow rate of fuel gas into the mixer  138  through the gas inlet  176 , thereby providing a convenient way to adjust a gas-air mixture that exits a mixer insert  180 . Mixer insert  180  is shaped to provide improved mixing of the air and gas as compared to the mixing of the air and gas that would otherwise occur in the tubing-shaped body  182  of the mixer  138 . The mixer  138  further comprises a mounting plate  184  for attachment to a burner manifold. 
         [0043]    Referring now to  FIG. 12 , an IR burner  136  is shown in greater detail. The IR burner  136  comprises a plurality of mixture inputs  186  that distribute the gas-air mixture along the length of a burner tube  188 . The IR burner  136  further comprises forms  190  that serve to hold ceramic reflector-emitters  192 . The reflector-emitters  192  serve the dual role of reflecting radiant heat in a concentrated manner in a direction generally away from the forms  190  while also becoming heated to emit infrared radiation. The emitted infrared radiation serves to heat foodstuff and the components that carry foodstuff along the cooking path. 
         [0044]    Referring now to  FIG. 13 , a belt guide  194  is shown. A plurality of belt guides  194  are used in oven  100  to maintain a front-to-back alignment of the belts  128 ,  130 ,  132 . To keep the belts  128 ,  130 ,  132  aligned from front to back, the belts  128 ,  130 ,  132  are guided between side pulleys  196  that oppose the front and rear sides of the belts  128 ,  130 ,  132 . To keep the belts  128 ,  130 ,  132  generally flat where appropriate, a support shaft  198  is provided with support gears  200  and support bearings  202 . The support shaft turns freely due to the support bearings  202  while the support gears  200  actually engage and vertically support the belts  128 ,  130 ,  132 . The support gears  200  have a larger diameter than the support bearings  202 . The components of the belt guide  194  are all commonly carried by a support bar  204  that is in turn supported by other structures of the oven  100 . 
         [0045]    Referring now to  FIG. 14 , belt tensioners  118  are shown that serve to provide a convenient adjustment to the tension of belts  128 ,  130 ,  132 . The belt tensioner  118  comprises an adjustable shaft mount  206  that allows upward or downward movement of tensioner drum  122 . As tensioner drum  122  is moved up, the tension of the belt is decreased. As the tensioner drum  122  is moved down, the tension of the belt is increased. 
         [0046]    Referring now to  FIG. 15 , an enlarged view of a motor  112 , gearbox  114 , and drive shaft  116  are shown in association with a drive drum  120  and a belt. Motor  112  is an electric motor, however, in alternative embodiments, the motor may be a pneumatic motor, hydraulic motor, or any other suitable motor. The motor  112  is connected to a gearbox  114  which is in turn connected to a drive shaft  116  that drives the drive drum  120 . When the drive drum  120  is rotated, the belt is moved. 
         [0047]    Referring now to  FIG. 16 , an alternative embodiment of an oven  400  is shown in simplified form. Oven  400  is substantially similar to oven  100  but for the choice of heat generators. Specifically, oven  400  comprises an upper belt  402 , a middle belt  404 , and a lower belt  406  that are connected and insulated to have a cooking zone substantially similar to the cooking zone of oven  100 . Oven  400  comprises a combination of slit-tube gas burners  408 , IR burners  410 , and microwave emitters  412 . Further, it will be appreciated that the slit-tube gas burners  408  and IR burners  410  associated with the middle belt  404  are oriented lengthwise with the middle belt  404 . However, the slit-tube gas burners  408  and IR burners  410  associated with the upper belt  402  are oriented generally across the upper belt  402  from front to back. Further, an oven zone  414  comprises a slit-tube gas burner  408 , an IR burner  410 , and a microwave emitter  412  within the oven zone  414  but outside the cooking zone. The oven zone  414  further comprises a forced air fan  416  for circulating air in the oven zone  414 . Of course, in alternative embodiments, the types of heat generators, the placement of the heat generators  408 ,  410 ,  412  and fans  416  may be different than shown and the various combinations of components and component placements may be used in combination with other embodiments disclosed herein. 
         [0048]    Referring now to  FIG. 17 , an alternative embodiment of an oven  500  is shown in simplified form. Oven  500  is substantially similar to oven  100  but for the placement of heat generators. Specifically, oven  500  comprises an upper belt  502 , a middle belt  504 , and a lower belt  506  that are connected and insulated to have a cooking zone substantially similar to the cooking zone of oven  100 . Oven  500  comprises IR burners  510 . IR burners  510  are placed continuously along both the top and bottom side of upper belt  502 . IR burners  510  are alternatingly placed along the middle belt  504  so that there is no overlap in IR burners  510  but also so that foodstuff is always directly above or directly below an IR burner  510  while on middle belt  504 . IR burners  510  are also placed substantially adjacent one another to form a series of adjacent IR burners  510  on the upper left side of the lower belt  506 . However, another series of adjacent IR burners  510  is located just to the right of the upper left series of IR burners  510  on the bottom side of the lower belt  506 . Another IR burner  510  is located near the right end of the lower belt  506  on the upper side of the lower belt  506  and is offset to the right from any IR burners  506  on the lower belt  506 . Finally, IR burners  510  are placed facing the left end of the upper belt  502 , the right end of the middle belt  504 , and the left end of the lower belt  506 . Further, it will be appreciated that while IR burners  510  are discussed in the particular layouts described above, in alternative embodiments, IR burners may be positioned along conveyor belts and positioned relative to each other in any other suitable manner. 
         [0049]    It will be appreciated that any of the insulators  140 ,  142 ,  144 ,  146 ,  148 ,  150 ,  160  may be constructed of stainless steel, Stainless Steel 253 MA™, high nickel steel, Rockwool™ materials, or any other suitable material. The insulators may be placed in relative close proximity to conveyor belts in such a way to maximize heat retention in the cooking zone (i.e. near the belts). It will further be appreciated that one advantage of the of using the IR burners  136  is that the effective cooking area of the IR burners  136  is essentially the footprint of the reflector-emitters  192  as compared to the effective cooking area of a gas flame being only the area of the gas flame. It will further be appreciated that while ovens  100 ,  400 , and  500  are disclosed as having three conveyor belts (i.e. a three-pass system), the principles disclosed herein can be equally applied to any oven having one, two, three, or more such conveyor systems. Specifically, for example, an oven may comprise a single conveyor within an insulated cooking zone where the cooking zone is further substantially enveloped within an insulated oven zone. 
         [0050]    Further, in alternative embodiments, an oven may comprise multiple conveyor belts at or near the same vertical level so that foodstuff is not dropped from one belt to another. Still further, in alternative embodiments, the cooking path may not comprise substantially level conveyor belts. Instead, an alternative embodiment may comprise a cooking path that spirals up or down, slopes up or down, or follows a meandering course. All of the above-described alternative embodiments may employ the method of reducing a required amount of energy to cook foodstuff by enclosing the cooking path using insulators located in close proximity to the cooking path (i.e. close to the conveyor belts). Further, all of the above-described alternative embodiments may employ the method of conserving heat and energy by ducting hot air and heat between various conveyors that are located at different vertical levels. Still further, all of the above-described alternative embodiments may employ the method of conserving heat and energy by further substantially enclosing a cooking zone within an oven zone using outer insulators. Finally, all of the above-described alternative embodiments may employ the use of IR burners to increase an effective cooking area as compared to using conventional slit-tube gas burner systems. 
         [0051]    At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R 1 , and an upper limit, R u , is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R 1 +k*(R u −R 1 ), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. The discussion of a reference in the disclosure is not an admission that it is prior art, especially any reference that has a publication date after the priority date of this application.