Secondary venting arrangement for gas oven cooking appliance

A cooking appliance includes a secondary venting arrangement within an oven cavity to supplement a primary venting arrangement with localized venting of combustion products adjacent a flame detector that detects a flame emitted by a gas burner disposed under the oven cavity. Doing so may assist with stabilizing the flame generated by the gas burner prior to establishment of steady state flow pattern within the oven cavity.

BACKGROUND

Cooking appliances that include ovens, e.g., ranges, wall-mounted ovens, and the like, generally incorporate multiple cooking elements disposed at different locations in an oven cavity. One or more bake cooking elements are generally positioned on the bottom or underneath the bottom of the oven cavity, while one or more broiler cooking elements are generally positioned near the top of the oven cavity (for the purpose of simplification, this description will use the term “cooking element” to refer to any of the various heat sources that may be utilized to generate the heat required for cooking, which may include, but are not limited to, resistive electrical heating elements, gas burners, infrared heaters, quartz heaters, etc.) Some cooking appliances may also include multiple ovens, each having multiple cooking burners within, and as such, some cooking appliances may include a multitude of cooking elements disposed therein.

In a cooking appliance that relies on gas burners as oven cooking elements, the appliance is generally designed to incorporate a path for drawing in fresh air for combustion and for venting the products of that combustion. A natural flow generally develops over time, in part due to the injection of gas and sometimes additional primary air to the internal volume of the appliance, which displaces the air within the volume. Upon startup and during the warm-up phase of the appliance this gas movement is less controlled, slower, and may even run counter to the flow that is established after the warmup period. As the appliance gets warm, buoyant forces come into play, whereby a pressure gradient is established and the hot air and products of combustion rise. An exhaust vent is generally disposed near the top of the volume such that the hot air and combustion products flow out of the exhaust vent. This ultimately produces a stable, steady state flow pattern through the entire cooking appliance, whereby fresh air is drawn to the gas burner and a hot mix of excess air and combustion products flow up and out through the exhaust vent.

It has been found, however, that while the flow is being established during the warmup phase, combustion is less than optimal, as are the quality and stability of the flames established at the gas burner. This is partially due to an inefficient influx of fresh air available to the flames and an inefficient evacuation of combustion products from the burner box surrounding the gas burner. When a flame sense rod or other flame detector is used to detect the presence of a flame, the signal it receives during this warmup period may also be affected due to poor contact with a less than optimal flame or flames.

Therefore, a need continues to exist in the art for a manner of improving combustion of a gas oven burner, particularly during a warmup phase prior to establishment of a steady state flow pattern.

SUMMARY

The herein-described embodiments address these and other problems associated with the art by providing a cooking appliance including a secondary venting arrangement within an oven cavity to supplement a primary venting arrangement with localized venting of combustion products adjacent a flame detector that detects a flame emitted by a gas burner disposed under the oven cavity. Doing so may assist with stabilizing the flame generated by the gas burner prior to establishment of steady state flow pattern within the oven cavity.

Therefore, consistent with one aspect of the invention, a cooking appliance may include a housing including an oven cavity, an exhaust vent disposed proximate a top of the oven cavity, a gas burner disposed under the oven cavity, a flame detector disposed adjacent to the gas burner and configured to detect a flame emitted by the gas burner, a primary venting arrangement disposed in a lower portion of the oven cavity, the primary venting arrangement configured to vent combustion products generated by the gas burner into the oven cavity and out the exhaust vent as a result of a steady state flow pattern established in the oven cavity after the oven cavity has been warmed by heat generated by the gas burner, and a secondary venting arrangement disposed in the lower portion of the oven cavity and adjacent to the flame detector, the secondary venting arrangement configured to stabilize the flame detected by the flame detector prior to establishment of the steady state flow pattern in the oven cavity through localized venting of combustion products generated by the gas burner into the oven cavity adjacent the flame detector.

Some embodiments may further include one or more fresh air inlets disposed underneath the oven cavity and configured to supply fresh air to the gas burner, and a flow divider disposed underneath the oven cavity and configured to separate the fresh air supplied by the one or more fresh air inlets from the combustion products vented through the primary venting arrangement, and the secondary venting arrangement may provide a shorter flow path around the flow divider than a flow path provided by the primary venting arrangement to reduce combustion product buildup in a volume adjacent the flame detector. Also, in some embodiments, the gas burner extends from a first end proximate a rear of the oven cavity towards a second end proximate a front of the oven cavity, and the flame detector is disposed proximate the first end of the gas burner.

In some embodiments, the gas burner is in fluid communication with a gas supply proximate the first end of the gas burner. In addition, in some embodiments, the one or more fresh air inlets includes first and second air inlets disposed underneath the oven cavity and respectively proximate first and second sides of the oven cavity, the primary venting arrangement includes first and second primary vents formed in a bottom panel of the oven cavity and respectively disposed proximate the first and second sides of the oven cavity, the flow divider extends along first and second sides of the gas burner, fresh air flows inwardly towards the gas burner from the first and second air inlets on an underside of the flow divider, at least a portion of the combustion products generated by the gas burner when the steady state flow pattern is established flow outwardly from the gas burner to the first and second primary vents on the topside of the flow divider, and the secondary venting arrangement is positioned relative to the gas burner and the flame detector such that at least a portion of the combustion products generated by the gas burner flow from the gas burner to the secondary venting arrangement without flowing over the topside of the flow divider.

Also, in some embodiments, the secondary venting arrangement includes one or more vents positioned rearwardly of a rear edge of the flow divider. In addition, some embodiments may further include a flame spreader positioned above the gas burner and extending towards the first and second sides of the oven cavity, and the secondary venting arrangement includes one or more vents positioned rearwardly of a rear edge of the flame spreader. Further, in some embodiments, the secondary venting arrangement includes one or more vents formed proximate a bottom of the oven cavity. Also, in some embodiments, the oven cavity includes a bottom panel, and the one or more vents are formed in the bottom panel. Further, in some embodiments, the bottom panel is removable from the oven cavity.

In some embodiments, the oven cavity includes a bottom panel supported on a flange circumscribing a bottom of the oven cavity, and the one or more vents are formed in part by one or more reliefs in the flange. Also, in some embodiments, the oven cavity includes a removable bottom panel supported by a fixed cavity portion, and the one or more vents are formed in the fixed cavity portion. In some embodiments, the one or more vents includes first and second vents respectively disposed proximate first and second sides of the gas burner. Further, in some embodiments, the one or more vents includes a first vent disposed directly above the flame detector. In some embodiments, the flame detector includes a flame sense rod.

These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described example embodiments of the invention. This summary is merely provided to introduce a selection of concepts that are further described below in the detailed description, and is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

DETAILED DESCRIPTION

Turning now to the drawings, wherein like numbers denote like parts throughout the several views,FIG.1illustrates an example cooking appliance10in which the various technologies and techniques described herein may be implemented. Cooking appliance10is a residential-type range, and as such includes a housing12, a stovetop or cooktop14including a plurality of burners16, and an oven18defining an oven or cooking cavity20accessed via an oven door22. Cooking appliance10may also include a storage drawer24in some embodiments, or in other embodiments, may include a second oven. Various cooking elements (not shown inFIG.1) may also be incorporated into cooking appliance10for cooking food in oven18, e.g., one or more electric or gas cooking elements.

Cooking appliance10may also include various user interface devices, including, for example, control knobs28for controlling burners16, a control panel30for controlling oven18and/or burners16, and a display32for providing visual feedback as to the activation state of the cooking appliance. It will be appreciated that cooking appliance10may include various types of user controls in other embodiments, including various combinations of switches, buttons, knobs and/or sliders, typically disposed at the rear or front (or both) of the cooking appliance. Further, in some embodiments, one or more touch screens may be employed for interaction with a user. As such, in some embodiments, display32may be touch sensitive to receive user input in addition to displaying status information and/or otherwise interacting with a user. In still other embodiments, cooking appliance10may be controllable remotely, e.g., via a smartphone, tablet, personal digital assistant or other networked computing device, e.g., using a web interface or a dedicated app.

Display32may also vary in different embodiments, and may include individual indicators, segmented alphanumeric displays, and/or dot matrix displays, and may be based on various types of display technologies, including LEDs, vacuum fluorescent displays, incandescent lights, etc. Further, in some embodiments audio feedback may be provided to a user via one or more speakers, and in some embodiments, user input may be received via a spoken or gesture-based interface.

As noted above, cooking appliance10ofFIG.1is a range, which combines both a stovetop and one or more ovens, and which in some embodiments may be a standalone or drop-in type of range. In other embodiments, however, cooking appliance10may be another type of cooking appliance, e.g., a wall mount or freestanding oven. In general, a cooking appliance consistent with the invention may be considered to include any residential-type appliance including a housing and one or more cooking elements disposed therein and configured to generate energy for cooking food within one or more oven cavities.

In turn, a cooking element may be considered to include practically any type of energy-producing element used in residential applications in connection with cooking food, e.g., employing various cooking technologies such as electric, gas, light, microwaves, induction, convection, radiation, etc. In the case of an oven, for example, one or more cooking elements therein may be gas, electric, light, or microwave cooking elements in some embodiments, while in the case of a stovetop, one or more cooking elements therein may be gas, electric, or inductive cooking elements in some embodiments. Further, it will be appreciated that any number of cooking elements may be provided in a cooking appliance (including multiple cooking elements for performing different types of cooking cycles such as baking or broiling, including multiple bake and/or multiple broiler cooking elements, as well as one or more convection cooking elements), and that multiple types of cooking elements may be combined in some embodiments, e.g., combinations of microwave and light cooking elements in some oven embodiments.

A cooking appliance consistent with the invention also generally includes one or more controllers configured to control the cooking elements and otherwise perform cooking operations at the direction of a user.FIG.2, for example, illustrates an example embodiment of a cooking appliance40including a controller42that receives inputs from a number of components and drives a number of components in response thereto. Controller42may, for example, include one or more processors44and a memory46within which may be stored program code for execution by the one or more processors. The memory may be embedded in controller42, but may also be considered to include volatile and/or non-volatile memories, cache memories, flash memories, programmable read-only memories, read-only memories, etc., as well as memory storage physically located elsewhere from controller42, e.g., in a mass storage device or on a remote computer interfaced with controller42.

As shown inFIG.2, controller42may be interfaced with various components, including various cooking elements48used for cooking food (e.g., various combinations of gas, electric, inductive, light, microwave, light cooking elements, among others), one or more user controls50for receiving user input (e.g., various combinations of switches, knobs, buttons, sliders, touchscreens or touch-sensitive displays, microphones or audio input devices, image capture devices, etc.), and a user display52(including various indicators, graphical displays, textual displays, speakers, etc.), as well as various additional components suitable for use in a cooking appliance, e.g., lighting54and/or one or more fans56(e.g., convection fans, cooling fans, etc.), among others. For cooking elements48implemented as gas burners, controller42may be interfaced with one or more gas valves for regulating gas flow to the gas burners, as well as one or more ignitors for igniting gas supplied to the gas burners; however, these components are not illustrated separately inFIG.2.

Controller42may also be interfaced with various sensors58located to sense environmental conditions inside of and/or external to cooking appliance40, e.g., one or more temperature sensors, humidity sensors, air quality sensors, smoke sensors, carbon monoxide sensors, odor sensors and/or electronic nose sensors, among others. Such sensors may be internal or external to cooking appliance40, and may be coupled wirelessly to controller42in some embodiments. Sensors58may include, for example, one or more temperature sensors for sensing an air temperature within an oven cavity, including, for example, a temperature sensor for sensing temperature in a center of the oven cavity and/or one or more temperature sensors for sensing temperature in the top and/or bottom of the oven cavity, as well as one or more flame detectors, e.g., flame sense rods or other suitable types of flame detectors capable of sensing a flame emitted by a gas burner.

In some embodiments, controller42may also be coupled to one or more network interfaces60, e.g., for interfacing with external devices via wired and/or wireless networks such as Ethernet, Wi-Fi, Bluetooth, NFC, cellular and other suitable networks, collectively represented inFIG.2at62. Network62may incorporate in some embodiments a home automation network, and various communication protocols may be supported, including various types of home automation communication protocols. In other embodiments, other wireless protocols, e.g., Wi-Fi or Bluetooth, may be used. In some embodiments, cooking appliance40may be interfaced with one or more user devices64over network62, e.g., computers, tablets, smart phones, wearable devices, etc., and through which cooking appliance40may be controlled and/or cooking appliance40may provide user feedback. Further, in some embodiments, cooking appliance40may be interfaced with one or more remote services66, e.g., cloud-based services, remote servers.

In some embodiments, controller42may operate under the control of an operating system and may execute or otherwise rely upon various computer software applications, components, programs, objects, modules, data structures, etc. In addition, controller42may also incorporate hardware logic to implement some or all of the functionality disclosed herein. Further, in some embodiments, the sequences of operations performed by controller42to implement the embodiments disclosed herein may be implemented using program code including one or more instructions that are resident at various times in various memory and storage devices, and that, when read and executed by one or more hardware-based processors, perform the operations embodying desired functionality. Moreover, in some embodiments, such program code may be distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of computer readable media used to actually carry out the distribution, including, for example, non-transitory computer readable storage media. In addition, it will be appreciated that the various operations described herein may be combined, split, reordered, reversed, varied, omitted, parallelized and/or supplemented with other techniques known in the art, and therefore, the invention is not limited to the particular sequences of operations described herein.

Numerous variations and modifications to the cooking appliances illustrated inFIGS.1-2will be apparent to one of ordinary skill in the art, as will become apparent from the description below. Therefore, the invention is not limited to the specific implementations discussed herein.

Secondary Venting Arrangement for Gas Oven Burner

As noted above, in a cooking appliance that relies on gas burners as oven cooking elements, the appliance is generally designed to incorporate a path for drawing in fresh air for combustion and for venting the products of that combustion.FIG.3, for example, illustrates an example cooking appliance100including a structure102defining an oven cavity104. Bake and broil gas oven burners106,108are disposed proximate the bottom and top of the oven cavity104, respectively. In some embodiments, broil gas oven burner108is disposed within the oven cavity104, e.g., under the top wall thereof, while bake gas oven burner106is disposed under the oven cavity104, e.g., within a burner box110that is separated from the oven cavity104by an oven bottom112, which may be removable in some embodiments.

Each gas oven burner106,108includes an associated flame detector114,116, igniter118,120, and flame spreader122,124. In addition, burner box110may also include one or more flow dividers126(which may also be considered to include a flow divider formed up multiple pieces) to separate the flow of incoming air to bake gas oven burner106from the flow of combustion products and excess air away from bake gas oven burner106. A primary venting arrangement, e.g., one or more vents,128, may be provided in oven bottom112to vent the combustion products and excess air into oven cavity104.

It will be appreciated that, when bake gas oven burner106is ignited and emitting a flame, a natural flow generally develops over time, in part due to the injection of gas and sometimes additional primary air to the internal volume of the appliance, which displaces the air within the volume. As the appliance gets warm, buoyant forces come into play, whereby a thermal gradient is established and the hot air and products of combustion rise. An exhaust vent130is generally disposed near the top of the volume such that the hot air and combustion products flow out of the exhaust vent. This ultimately produces a stable, steady state flow pattern, represented by the arrows inFIG.3, whereby fresh air is drawn into burner box110, generally from the sides and underneath flow divider126and to bake oven gas burner106. The fresh air is combusted with gas supplied to bake oven gas burner106, and a hot mix of excess air and combustion products flow from bake oven gas burner106, generally within the volume between flow divider126and oven bottom112, out through vents128and into oven cavity104. The flow then continues upwards and out through exhaust vent130.

As illustrated by the arrows inFIG.4, however, upon startup and during the warm-up phase of the cooking appliance, this gas movement is less controlled, slower, and may even run counter to the steady state flow pattern that is established after the warmup period. As a result, combustion is less than optimal, as are the quality and stability of the flames established at bake oven gas burner106. This is partially due to an inefficient influx of fresh air available to the flames and an inefficient evacuation of combustion products from burner box110, and in some instances, this inefficient flow is exacerbated by the presence of the flow divider126and the relatively long and tortuous path the combustion products must take from the bake oven gas burner106(which is generally centrally located) to the vents128(which are generally positioned proximate the side walls of the oven cavity. Furthermore, due to the instability of the flame due to the sub-optimal combustion, flame detector114may receive a signal during this warmup period that is intermittent and/or inconclusive due to poor contact with a less than optimal flame or flames.

Embodiments consistent with the invention, however, may incorporate a secondary venting arrangement that provides an alternate flow path to that of the primary venting arrangement that short-cuts the flow temporarily until the steady state flow paths are established, thereby providing stronger flames in the area of the flame detector with improved air supply and improved venting. The secondary venting arrangement in particular may be disposed in a lower portion of an oven cavity and adjacent to the flame detector, and may be configured to stabilize the flame detected by the flame detector prior to establishment of the steady state flow pattern in the oven cavity through localized venting of combustion products generated by the gas burner into the oven cavity adjacent the flame detector.

Localized venting, in this regard, refers to venting that is in the immediate vicinity of the flame detector, and in some embodiments, venting that is unobstructed by a flow divider or other intermediate structure, such that a direct flow path is created from the volume surrounding the flame detector and one or more vents comprising the secondary venting arrangement. Furthermore, to the extent that any flow divider is utilized in a burner box housing a gas burner, localized venting effectively bypasses that flow divider to reduce combustion product buildup in the volume adjacent to and surrounding the flame detector.

FIGS.5-8, for example, illustrate an example cooking appliance140including a housing or structure142defining an oven cavity144. Bake and broil gas oven burners146,148are disposed proximate the bottom and top of the oven cavity144, respectively. Broil gas oven burner148is disposed within the oven cavity144, e.g., under the top wall thereof, while bake gas oven burner146(FIGS.6and7) is disposed under the oven cavity144, e.g., within a burner box150that is separated from the oven cavity144by an oven bottom152, which may be configured as a removable bottom panel in some embodiments.

Each gas oven burner146,148includes an associated flame detector positioned adjacent to the gas oven burner (e.g., flame detector154for bake gas oven burner146, here implemented as a flame sense rod) and flame spreader (e.g., flame spreader156for bake gas oven burner146). Further, in the illustrated embodiment, each gas oven burner146,148includes an igniter (e.g., igniter158for bake gas oven burner146) configured to ignite gas supplied to the gas oven burner and a gas valve configured to supply gas from a gas supply to the gas oven burner. While igniter158is illustrated as being on the opposite side of bake gas oven burner146as flame detector154, it will be appreciated that in other embodiments, these components may be disposed at other locations, e.g., at opposite ends, at the same end and side, etc.

It will be appreciated that in this embodiment, bake gas oven burner146extends from a first end proximate a rear of the oven cavity144towards a second end proximate a front of oven cavity144, and is in fluid communication with the gas supply through a gas valve (not shown inFIG.7) proximate its first end. Furthermore, flame detector154is disposed proximate the first end of the bake gas oven burner146, and flame spreader156extends generally laterally (i.e., side-to-side) from bake gas oven burner146. Other burner configurations, e.g., U-shaped or side-to-side, may be used in other embodiments.

Fresh air in cooking appliance140is generally supplied from the left and right sides of the appliance, e.g., through fresh air inlets formed in the sides of burner box150. In other embodiments, fresh air may be supplied from fresh air inlets formed in the center, front and/or back of the burner box, so the invention is not limited to fresh air inlets disposed on the side of the burner box. Flow divider162(FIG.6) extends underneath oven cavity144and laterally across each side of bake gas oven burner146such that fresh air entering the sides of burner box150passes along the underside of the flow divider and to the bake gas oven burner146for combustion. Combustion products generated by the bake gas oven burner146then pass along the topside of flow divider162and underneath flame spreader156and oven bottom152.

A primary venting arrangement disposed in a lower portion of oven cavity144, here including a pair of primary vents166,168, is configured to vent combustion products and excess air into oven cavity144and out an exhaust vent170as a result of a steady state flow pattern established in oven cavity144after oven cavity144has been warmed by heat generated by the bake gas oven burner146. At least some of the combustion products and any excess air is thus carried across the topside of flow divider162and underneath flame spreader156, through vents166,168and into oven cavity144, and then out of oven cavity144and through exhaust vent170.

In this embodiment, a secondary venting arrangement172, incorporating a plurality (e.g., four) vents174, is disposed in the lower portion of oven cavity144and adjacent to the flame detector. Secondary venting arrangement172is configured to stabilize the flame detected by flame detector154prior to establishment of the steady state flow pattern in oven cavity144through localized venting of combustion products generated by bake gas oven burner146into oven cavity144adjacent flame detector154. In addition, for at least one or more of vents174, the secondary venting arrangement172effectively bypasses flow divider162for at least a portion of the combustion products and excess air to reduce the amount of combustion products building in the volume adjacent flame detector154, whereby at least a portion of the combustion products generated by bake gas oven burner146flow from the bake gas oven burner to secondary venting arrangement172without flowing over the topside of flow divider162(and underneath flame spreader156) to primary vents166,168. Further, as it may be seen fromFIG.7, vents174are positioned rearwardly of one or both of a rearward edge of flame spreader156and a rearward edge of flow divider162(vents174are positioned rearwardly of the rearward edge of flame spreader156but not rearwardly of the rearward edge of flow divider162inFIG.7), thereby providing a relatively straight and unobstructed flow path from the volume adjacent the flame detector154to vents174. It should be noted that this path is also shorter in length than the paths to primary vents166,168. In addition, at least one of vents174may be directly above flame detector154in some embodiments.

Thus, during startup and prior to establishing a steady state flow pattern, at least a portion of the combustion products and excess air in the vicinity surrounding flame detector154will flow through vents174of secondary venting arrangement172rather than primary vents166,168, thereby establishing stronger flames in the area of the flame detector with improved air supply and improved venting. A portion of the combustion products and excess air may still be vented through primary vents166,168during this time, and it will further be appreciated that once the thermal gradient and steady state flow pattern have been established, combustion products and excess air may still be vented through both the primary and secondary venting arrangements.

It will be appreciated that while four individual vents174are illustrated for secondary venting arrangement172, and the primary venting arrangement is implemented using two primary vents166,168running proximate the left and right sides of oven cavity144inFIGS.5-8, different numbers and/or locations of vents may be used for either venting arrangement in other embodiments, e.g., more vents, or as few as one vent for each of the primary and secondary venting arrangements.

In addition, while vents174of secondary venting arrangement172are illustrated as being disposed in a removable bottom panel forming oven bottom152inFIGS.5-8, in other embodiments, a secondary venting arrangement may include vents disposed in other structures proximate the bottom of an oven cavity.FIG.9, for example, illustrates an example cooking appliance200in which a structure or housing202includes a removable bottom panel204that is supported by a fixed cavity portion206. While primary vents208,210are still disposed on the removable bottom panel204, a secondary venting arrangement212, including vents214, is disposed in the fixed portion206.

As another example,FIG.10illustrates an example cooking appliance220in which a structure or housing222includes a bottom panel224that is supported by a flange226. While primary vents228,230are still disposed on the removable bottom panel224, a secondary venting arrangement232, including vents234, is formed from reliefs in flange226. A rear edge236of bottom panel224is separated from a rear wall238of the oven cavity to expose flange226, such that the reliefs form vents234of secondary venting arrangement232.

Other vent locations, including combinations of vents disposed in the various locations illustrated inFIGS.8-10, may be used in other embodiments, as will be appreciated by those of ordinary skill having the benefit of the instant disclosure.

It will be appreciated that various additional modifications may be made to the embodiments discussed herein, and that a number of the concepts disclosed herein may be used in combination with one another or may be used separately. Therefore, the invention lies in the claims hereinafter appended.