Patent Application
20140312025
The present invention relates to commercial ovens and in particular to an oven that may be placed closely adjacent to other heating devices.
Commercial ovens may include features such as forced and heated airflow through the cooking cavity (convection cooking) and the introduction of steam into the cooking cavity (steam cooking). The fan motor for convection cooking, the water handling system for steam cooking, and control electronics for each are normally held in an equipment compartment that is maintained at a substantially lower temperature than the cooking cavity compatible with electrical and electromechanical components.
The equipment compartment is normally adjacent to the cooking cavity to provide for the necessary mechanical and electrical connections between equipment of the equipment compartment and the fan, steam nozzles, and sensors within the cooking cavity. This close proximity results in substantial heat transfer from the cooking cavity and the electrical compartment which, if unaddressed, would unacceptably raise the temperature of the equipment compartment. For this reason, the equipment compartment normally includes one or more cooling fans pulling cool air from outside of the oven housing to pass through the equipment compartment.
The ability to properly cool the equipment compartment with external air is founded on some assumptions about the environment of the oven including assumptions about the temperature of the air being drawn into the oven and assumptions that the primary heat entering the equipment compartment comes from the oven cavity and internally generated heat from the electrical and electromechanical components. These assumptions are normally enforced by requiring that the oven have a minimum clearance distance from other equipment that may present a source of radiated or conducted heat or heated air that could cause the local environment of the equipment compartment to rise beyond the expected normal range.
Providing this clearance in environments where space is scarce and/or enforcing the observation of this clearance in all oven installations can be difficult.
The present invention provides an oven with a “zero clearance” outer wall having an internal air circulation plenum just inside the outer wall. By providing forced airflow through the plenum, the plenum internalizes otherwise necessary external clearance distances but with a thickness that can be less than that required external clearance distance as a result of the airflow effect. The plenum system can eliminate or reduce passive thermal insulation that might otherwise be required allowing improved access to the equipment compartment.
Specifically, in one embodiment, the present invention provides an oven having a housing providing an oven compartment and an adjacent equipment compartment each having a shared wall and independent outer vertical walls. A heater communicates with the oven compartment to preferentially heat the oven compartment for cooking food, and electronic equipment for the operation of the oven is held in the equipment compartment. A plenum is attached to an inner surface of the outer vertical wall of the equipment compartment to promote a flow of air along the inner surface of the outer vertical wall as part of a path from an intake point outside of the housing to an exit point outside of the housing.
It is thus a feature of at least one embodiment of the invention to provide a compact virtual insulation inside the outer wall of the equipment compartment permitting the oven to be placed against other equipment that may also generate heat.
The air intake point may be located at a bottom of the housing and the air exit point may be located at the top of the housing.
It is thus a feature of at least one embodiment of the invention to promote airflow using natural convection and to take advantage of the typical favorable air temperature differences and flow patterns within a kitchen.
The oven may include a fan for drawing air into the housing and through the plenum.
It is thus a feature of at least one embodiment of the invention to provide an extremely thin plenum through the use of forced airflow.
The fan may separately circulate air through the plenum and the equipment compartment.
It is thus a feature of at least one embodiment of the invention to take advantage of an existing cooling fan used to cool the equipment compartment to also supply air to the plenum.
The oven may include airflow restrictors interfacing with the plenum for guiding air through the plenum.
It is thus a feature of at least one embodiment of the invention provide a simple method to control a ratio of airflow into separate paths through the equipment cabinet and the plenum from a single fan.
The fan may be located near the bottom of the housing to draw air into the housing and the oven may further include a second fan located near the top of the housing to exhaust air out of the top of the housing.
It is thus a feature of at least one embodiment of the invention to provide improved control of airflow through the equipment compartment and plenum through the use of paired intake and exhaust fans.
The oven may further include a third fan located near a front top of the housing to draw air into the housing wherein the second fan is positioned near the rear of the housing.
It is thus a feature of at least one embodiment of the invention to promote a rearward exhausting away from the user and dilution of that discharged air.
The outer vertical wall of the equipment compartment may be removable for access to the equipment compartment by releasable fasteners and the plenum may be a sheet attached to and spaced from an inner surface of the outer vertical wall covering substantially the entire inner surface of the outer vertical wall.
It is thus a feature of at least one embodiment of the invention to provide the benefits of the plenum described above without substantially impeding access to the equipment cabinet necessary for maintenance and repair.
The outer vertical wall of the equipment compartment may be a metal sheet and the plenum may be welded to an inner surface of the outer vertical wall.
It is thus a feature of at least one embodiment of the invention to provide a simple plenum structure that may attach to the outer vertical wall for easy removal of the two in unison.
The plenum may have additional heat limiting insulation added to the innermost wall of the plenum or to the outer wall of the oven or between the electronic equipment and the outer wall to provide even greater heat resistance without restricting the air flow through the plenum.
It is thus a feature of at least one embodiment of the invention to permit augmentation of the virtual insulation of the plenum with insulation to provide a flexible trade-off between plenum size and airflow rate and heat resistance.
In some embodiments, however the invention also contemplates that the outer wall of the oven an inner wall of the plenum and that nonstructural insulation may be eliminated between the electronic equipment and the outer wall.
It is thus a feature of at least one embodiment of the invention to make use of the virtual insulation without additional insulation in the plenum to eliminate the need for separate passive insulation that may block ready access to the equipment of the equipment compartment and use valuable equipment compartment volume.
The equipment compartment may include a motor providing a fan for circulating air in the oven cavity or may include plumbing and an electronically controlled valve for controlling water for the generation of steam in the oven cavity, and/or an electronic computer.
It is thus a feature of at least one embodiment of the invention to provide an equipment compartment that is sufficiently cool to hold the elements necessary for convection and steam cooking.
These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.
Referring now to
The oven compartment 14, in turn, holds an oven cavity 18 that may be accessed through a door 20, the latter connected by a hinge at one vertical side of the oven cavity 18. As is generally understood in the art, the door 20 may close over the oven cavity 18 during cooking operation as held by a latch assembly 22 (visible on the door 20 only). In the closed position, the door 20 may substantially seal against the oven cavity 18 by compressing against a gasket 24 surrounding an opening of the oven cavity 18 in the housing 12. Sidewalls of the oven cavity 18 may provide for rack supports 11 holding conventional cooking racks for supporting pans or trays of food.
The equipment compartment 16 is positioned to the side of the oven compartment 14 and supports on a front exposed wall of the equipment compartment 16 a control panel 28 accessible by a user standing at a front of the oven 10. The control panel 28 may provide conventional electronic controls such as switches, buttons, a touchscreen or the like that may receive oven control data from the user as will be described below. The equipment compartment 16 further has an external vertical sidewall 25 not shared with the oven compartment 14 (generally to the left sidewall of the oven 10 as depicted in
Referring now to
A heater 36 may be positioned adjacent to and surrounding the convection fan 34 to heat the air 142 discharged from the convection fan 34. The heater 36 may be an electric heating element holding electrical resistance element or a tubular heat exchanger receiving flue gases from a gas flame or the like.
In some embodiments, steam may be introduced into the oven cavity 18 as produced by a water jet 39 directing a spray of water on the convection fan 34 and/or heater 36 proximate to the fan 34. The supporting plumbing and an electrically controlled valve 40 for control of the water jet 39 may be placed in the equipment compartment 16. Alternatively steam may be provided by a separate boiler 21 having a dedicated heater element 23 and communicating with the oven cavity 18. In this case, the heater elements and tank filling valves and plumbing of this boiler may be controlled by circuitry within the equipment compartment 16.
An electronic control circuit 38 may be positioned within the equipment compartment 16 communicating with the control panel 28 (shown in
Ovens of this type are commercially available from the Alto-Shaam Inc. of Menomonee Falls, Wis. and are described generally in U.S. Pat. No. 6,188,045 “Combination Oven with Three Stage Water Atomizer” hereby incorporated by reference.
Referring now to
Referring now to
Referring now to
In this respect, the restrictor plate 48 allows for balancing the plenum stream 64 and equipment stream 66 by adding a flow resistance 70 experienced only by the equipment stream 66. The flow resistance 70 sums with a general equipment resistance 72 caused by air resistance experienced by the equipment stream 66 in passing over the electrical equipment outside of the plenum channel 54. In contrast, the plenum stream 64 experience is only a resistance 74 associated with the plenum 52 and the path into and out of the plenum channel 54 that avoids the restrictor plate 48. It will thus be seen that the restrictor plate 48 may be adjusted to control the airflow through the plenum channel 54 under the principle that additional airflow in the plenum stream 64 occurs when resistance 70 increases. In this way a single set of fans 44 also used for cooling equipment compartment 16 may be enlisted in creating the airflow through the plenum channel 54.
Referring now to
While the invention contemplates that the plenum 52 alone, with sufficient airflow, will allow operation of the oven 10 adjacent to other cooking equipment 90 without the use of “passive” nonstructural insulation such as fiberglass batting, it will be appreciated that such additional insulation material including coatings, reflective materials, and air entraining materials may be used to augment the action of the plenum 52. For example, passive insulation material 93 may be placed on the outer surface of the sidewall 25 to resist the flow of heat 92 and to increase the separation between the oven 10 and the cooking equipment 90. In addition or instead, passive insulation material 95 may be placed on the inner surface of the plenum 52. Both of these approaches minimize interference with access to the interior of the equipment compartment 16 when the sidewall 25 is removed and minimize interference with airflow through the plenum channel 54. Additional insulating material (not shown) may also be placed unattached to the structure of the sidewall 25 in the equipment compartment 16.
Generally the “virtual insulation” provided by the plenum 52 makes it possible to eliminate nonstructural insulation such as fiberglass batting placed between the electrical components of the equipment compartment 16 and the sidewall 25 allowing improved access to the electrical components for service and the like when the sidewall 25 is removed. The moving air through the plenum channel 54 allows the thickness of the channel to be greatly reduced from the size of the external clearance that would otherwise be required between cooking equipment 90 and the sidewall 25.
It will be understood generally that one or more of the fans 44a-44c may be controlled thermostatically to reduce energy consumption when environmental conditions or site conditions do not require the fans to be on at all times.
Referring now to
Referring now generally to
Upper and lower ends of the tubular portion 106 may connect to capping portions 108 having a circular cross-section conforming in diameter to the ends of the tubular portion 106 at their point of attachment and arcing backward toward the door 20 to present an oblique face 110 tipped at approximately 45 degrees to axis of rotation 104.
A front facing surface of the tubular portion 106 opposite a point of attachment of the tubular portion 106 to the shaft 102 may present a translucent elongate window 112 extending along the majority of length of the tubular portion 106 in a vertical direction to be visible to a user facing the door 20.
Referring now to
The LEDs 114 may communicate with an LED power supply 118, for example a constant current source communicating with a series connection of the LEDs 114. The LED power supply 118 may receive a control signal from the control circuit 38 to turn the LEDs 114 on and off in unison.
As mentioned above, the controller circuit 38 may include a processor 121 and a memory 122 holding a stored program 124 for implementing control of the oven and of the LEDs 114 through the power supply 118. Specifically, referring also to
Referring now to
After one or more cycles around the fan 34, the conduit 141 may be received by an inner heat exchanger 146 before discharging through exhaust pipe 148. A water conduit 150 may pass through the heat exchanger 146. Water within the water conduit 150 is circulated by a pump 152 to receive heat from the heated gases from the combustion chamber 142 after heating the air 143 but before passing out of the exhaust pipe 148. The heat exchanger 146 thus transfers otherwise wasted heat into water in the water conduit 150, heating the water and cooling the exhausted gases to provide a lower heat load to the kitchen.
The heated water may be received within a heat storage tank 154 that is thermally insulated to hold heat therein. A secondary heat exchanger 156 is then provided by a second water conduit 158 passing through the heated water of the storage tank 154, the second water conduit 158 receiving water received from a freshwater source 160. This heated water of second water conduit 158 may pass through a valve 162 to be sent either to a spray nozzle 164 for use in cleaning the oven between cooking sessions, or to the water jet 39 where the preheated water is more readily turned into steam, saving energy in this steam conversion process. This steam is generated by further heating of the water by the heater 36 around the fan 34 then passes along with the air 142 into the cooking cavity for steam cooking as is understood in the art. It will be appreciated that the heat storage tank 154 allows heated water be generated from second water conduit 158 for the purpose of cleaning even after the oven is off.
Generally, the heat storage tank 154 includes freshwater makeup valving and overflows to keep heat storage tank 154 filled with water and to control the temperature of the contained water to less than boiling.
The inner heat exchanger 146 providing heat to the water conduit 150 may be jacketed with an outer heat exchanger 166 which is fed by air intake fan 168 receiving fresh air from outside of the oven 10 and conducting it through the heat exchanger 166 to pick up additional heat from the outside of the conduit 141 that surrounds the water conduit 150. This heated air is then received by a browning conduit 170 which may be directed, for example, inside the oven cavity toward a particular rack or multiple racks to provide for elevated temperature air suitable for producing high temperature gradients within the oven that induce browning on the surface of foods.
Referring now to
Referring now to
Generally the systems as described reduce the need for separate heating sources for heating water and browning air, make additional use of waste heat from the oven thereby serving to reduce kitchen heat load.
Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
References to “a control board” and “a processor” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network.
It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.
