Inward Fired Dual-Stage Radial Gas Burner Assembly for Cooktop Appliance

The present subject matter relates generally to cooktop appliances with gas burner assemblies, such as gas range appliances or gas stove appliances.

Certain cooktop appliances include gas burners for heating cooking utensils on the cooktop appliances. Gas burners that fire inwards, typically with a swirling flame pattern, offer better efficiency than traditional outward firing gas burners. However, known inward firing gas burners have various drawbacks.

One drawback to inward fired single flame ring burners is a large diameter of the flame ring relative to a power output from the flame ring. The perimeter of the flame ring that defines the flame ports is generally greater than an equivalently-powered radially outward fired burner. Consequently, a minimum power that an inward swirl burner may decrease to (i.e., turndown) is higher than other burners (e.g., outward fired burners) to avoid flame blow out (i.e., loss of flame). The minimum power that the inward swirl burner may decrease to may be up to double the minimum power of other burners of similar power output. Stated differently, a turndown ratio for a non-inward fired swirl burner may be up to double a turndown ratio for an inward fired swirl burner having similar powers.

Consequently, inward swirl burners struggle to provide low heat settings, such as may be used for melting chocolate, or for extended simmering of sauces. Inward swirl burners struggle to turndown to low heat settings without risking flame stability or extinction, requiring relatively higher heat output at low heat settings which may be unsuitable for simmering, melting, etc.

A multi-ring inward fired burner may provide benefits for high heat tasks (e.g., boiling) while also providing a reduced minimum power for low heat tasks as compared to a single flame ring inward burner, via a smaller inner flame ring. However, despite providing a lower minimum heat, a centrally-positioned inward swirl burner positioned near a cooking utensil may concentrate heat to a center region, which may be disadvantageous for uniform, even heating tasks (e.g., simmering).

Additionally, or alternatively, multi-ring inward fired burners may collect unburned fuel in the center during initial startup if an ignition spark is not provided within a relatively immediate period of time. Structures for mitigating such pooling may add costs.

A multi-ring inward fired gas burner addressing one or more of these issues would be advantageous and beneficial. Furthermore, a cooktop appliance and multi-ring inward fired gas burner addressing one or more of these issues would be advantageous and beneficial.

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

An aspect of the present disclosure is directed to a gas burner assembly for a cooktop appliance. The gas burner assembly includes a first burner body and a second burner body. The first burner body includes a plurality of first flame ports distributed along a circumferential direction about a central combustion zone radially inward of the plurality of first flame ports. The first burner body includes a first mixing chamber fluidly coupled to the plurality of first flame ports to distribute a first flow of fuel therethrough. The second burner body includes a plurality of second flame ports distributed along the circumferential direction about the central combustion zone. The second burner body includes a second mixing chamber fluidly coupled to the plurality of second flame ports to distribute a second flow of fuel therethrough. The second burner body is positioned radially inward of the first burner body, and the plurality of second flame ports is positioned along an axial direction below the plurality of first flame ports.

Another aspect of the present disclosure is directed to a cooktop appliance. The cooktop appliance include a gas burner assembly positioned at a top panel. The gas burner assembly includes a first burner body and a second burner body. The first burner body includes a first inner side wall and a first outer side wall. A plurality of first flame ports is distributed through the first inner side wall along a circumferential direction about a first central combustion zone radially inward of the plurality of first flame ports. The first burner body includes a first mixing chamber positioned between the first inner side wall and the first outer side wall. The first mixing chamber is fluidly coupled to the plurality of first flame ports to distribute a first flow of fuel therethrough. A second burner body includes a second inner side wall and a second outer side wall. A plurality of second flame ports is distributed through the second inner side wall along the circumferential direction about a second central combustion zone radially inward of the plurality of second flame ports. The second burner body includes a second mixing chamber positioned between the second inner side wall and the second outer side wall. The second mixing chamber is fluidly coupled to the plurality of second flame ports to distribute a second flow of fuel therethrough. The second burner body is positioned radially inward of the first burner body. The plurality of second flame ports is positioned along an axial direction below the plurality of first flame ports.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). The terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative flow direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the flow direction from which the fluid flows, and “downstream” refers to the flow direction to which the fluid flows.

Embodiments of a cooktop appliance and multi-ring inward-fired swirl burner assembly addressing one or more of the aforementioned issues are provided. Embodiments described herein provide an inward-fired multi ring swirl burner assembly having a first inward-fired burner ring (outer burner) positioned radially outward of a second inward-fired burner ring (inner burner). The flame ports of the inner burner are positioned at a height above the cooktop that is below that of a flame ring of the outer burner. The height may facilitate an increased distance to diffuse heat from the inner burner before impinging on the bottom surface of cookware at the burner assembly. In various embodiments, a height separation may provide an additional twelve (12) millimeters or 0.5 inches of distance (e.g., along a vertical direction) to diffuse gases from the inner burner. Still various embodiments may include a cap of the inner burner contoured with a height that is proximate to, or above, the height of the flame ports at the outer burner. The cap of the inner burner may form a deflector for gas accumulation from the outer burner.

In various embodiments, the multi-ring inward-fired swirl burner assembly includes the inner and outer burners having concentric rings and a hollow center. The hollow center may be free of, or substantially free of, burner assembly structure or material at the combustion zone(s). A swirl component at flame ports of the inner and outer burners may be directionally similar to one another. A mixing throat may provide gaseous fuel to mixing chambers at the inner and outer burner rings. The mixing throat may include one or more offset, vertically-extending mixing throats.

Turning now to the figures,provides a front, perspective view of a cooktop applianceas may be employed with the present disclosure.provides a top, plan view of cooktop appliance. Cooktop applianceincludes an insulated cabinet. Cabinetdefines an upper cooking chamberand a lower cooking chamber. Thus, cooktop applianceis generally referred to as a double oven range appliance. As will be understood by those skilled in the art, cooktop applianceis provided by way of example only, and the present disclosure may be used in any suitable appliance (e.g., a single oven range appliance or a standalone cooktop appliance). Thus, the exemplary embodiment shown inis not intended to limit the present disclosure to any particular cooking chamber configuration or arrangement.

Upper and lower cooking chambersandare configured for the receipt of one or more food items to be cooked. Cooktop applianceincludes an upper doorand a lower doorrotatably attached to cabinetin order to permit selective access to upper cooking chamberand lower cooking chamber, respectively. Handlesare mounted to upper and lower doorsandto assist a user with opening and closing doorsandin order to access cooking chambersand. As an example, a user can pull on handlemounted to upper doorto open or close upper doorand access upper cooking chamber. Glass windowpanesprovide for viewing the contents of upper and lower cooking chambersandwhen doorsandare closed and also assist with insulating upper and lower cooking chambersand. Heating elements (not shown), such as electric resistance heating elements, gas burners, microwave heating elements, halogen heating elements, or suitable combinations thereof, are positioned within upper cooking chamberand lower cooking chamberfor heating upper cooking chamberand lower cooking chamber.

Cooktop appliancealso includes a cooktop. Cooktopis positioned at or adjacent a top portion of cabinet. Thus, cooktopis positioned above upper and lower cooking chambersand. Cooktopmay include a top panel. By way of example, top panelmay be constructed of glass, ceramics, enameled steel, and combinations thereof. Moreover, top panelmay be formed as a unitary, single piece or, alternatively, as multiple discrete pieces joined together.

For cooktop appliance, a utensil holding food or cooking liquids (e.g., oil, water, etc.) may be placed onto gratesat a location of any of burner assemblies,,,. Burner assemblies,,,provide thermal energy to cooking utensils on grates. As shown in, burners assemblies,,,can be configured in various sizes so as to provide, for example, for the receipt of cooking utensils (e.g., pots, pans, etc.) of various sizes and configurations and to provide different heat inputs for such cooking utensils. Gratesmay be supported on a top surfaceof top panel. In optional embodiments, cooktop applianceincludes a griddle burnerpositioned at a middle portion of top panel, as may be seen in. A griddle may be positioned on gratesand heated with griddle burner.

A user interface panelis located within convenient reach of a user of the cooktop appliance. For this exemplary embodiment, user interface panelincludes knobsthat are each associated with one of burner assemblies,,,and griddle burner. Knobsallow the user to activate each burner assembly and determine the amount of heat input provided by each burner assembly,,,and griddle burnerto a cooking utensil located thereon. User interface panelmay also be provided with one or more graphical display devices that deliver certain information to the user such as, for example, whether a particular burner assembly is activated or the rate at which the burner assembly is set.

Although shown with knobs, it should be understood that knobsand the configuration of cooktop applianceshown inis provided by way of example only. More specifically, user interface panelmay include various input components, such as one or more of a variety of touch-type controls, electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface panelmay include other display components, such as a digital or analog display device designed to provide operational feedback to a user.

Turning now to, perspective, cutaway, and exploded views of an exemplary embodiment of a multi-ring inward-fired gas burner assembly (hereinafter, “burner assembly”) are provided. As an example, burner assemblymay be used in cooktop appliance() as one of burner assemblies,,,,. Nonetheless, it will be understood that, while described in greater detail below in the context of cooktop applianceor cooktop, burner assemblymay be used in or with any suitable appliance in alternative exemplary embodiments.

Generally, burner assemblyincludes a pair of substantially concentric inner burner rings configured as inward firing, such as with a swirling flame pattern. As discussed in greater detail below, burner assemblyincludes features for managing or mitigating heat at top panel(e.g., to prevent damage thereto). Burner assemblydefines an axial direction A, a radial direction R, and a circumferential direction C.

When assembled, burner assemblyis positioned at top panel. As noted above, top panelmay include multiple discrete elements or, alternatively, a single integral unitary piece (e.g., formed from sheet metal). Thus, burner assemblymay be positioned at a specific separable portion of top panel(e.g., a mounting pan mounted to or supported on a support plate of top panel). Burner assemblyincludes a first or outer burner bodyand a second or inner burner body. Burner bodies,form annular burner rings. Burner bodies,may be positioned on top panel. For example, burner bodies,may rest on top panelsuch that burner bodies,are not fastened or otherwise mechanically fixed to top panel. Thus, a user may simply lift burner bodies,upwardly (e.g., along axial direction A) away from top panelto remove one or both of burner bodies,from top panel.

Annular outer burner bodydefines a central combustion zone. Burner bodyincludes a plurality of flame ports(e.g., at or facing central combustion zone). Flame portsmay be distributed, for example, along the circumferential direction C, about central combustion zone. Gaseous fuel is thus flowable from mixing chamberwithin burner bodyinto central combustion zonethrough flame ports. Flame portsmay also be oriented such that the gaseous fuel flows in a swirling pattern from flame portsinto central combustion zone.

In certain embodiments, burner bodyincludes an inner side walland an outer side wall. Inner side wallmay extend around central combustion zone(e.g., along the circumferential direction C). Flame portsmay be formed on or extend through inner side wall(e.g., substantially along the radial direction R, or additionally, along radial direction R and circumferential direction C, between mixing chamberand central combustion zone). Outer side wallmay extend around inner side wall(e.g., along the circumferential direction C). Outer side wallmay also be spaced from inner side wall(e.g., along the radial direction R). Mixing chambermay be defined and positioned between inner and outer side walls,(e.g., along the radial direction R, within annular burner body).

Burner bodyis open at central combustion zone. For example, no portion or component of burner bodymay extend (e.g., inward or otherwise along the radial direction R) into central combustion zone. In some embodiments, no fuel-providing structure extends into the central combustion zone. Top panelmay be exposed through burner bodyat central combustion zone. Specifically, a circumferentially bounded portion of top panel(e.g., bounded by burner body) may be exposed along the axial direction A. In such a manner, spills from utensils above burner assemblymay flow through central combustion zoneto top panel, and such spills may pass through burner assemblywithout contacting burner assemblyat central combustion zone. Staining of burner bodymay be reduced or limited by allowing spills to pass through burner bodyat central combustion zone.

Burner bodymay include an annular burner baseand an annular burner head. Burner baseincludes inlet passagesconfigured to receive a flow of gaseous fuel from a mixing tube, such as a vertical Venturi mixing tube. Burner headmay be positioned on burner baseto form mixing chamberof burner body. Thus, burner basemay form a bottom wall of mixing chamber, and burner headmay form a top wall of mixing chamber. Burner baseor burner headmay be formed of a cast metal, such as cast iron or cast aluminum alloy.

In some embodiments, burner bodymay also include burner cap. For instance, burner capmay be positioned on burner headsuch that annular burner capcovers annular burner head. Annular burner capmay reduce staining of annular burner baseor annular burner head.

Annular inner burner bodymay be formed substantially similarly as outer burner body. Inner burner bodydefines a central combustion zone. Burner bodyincludes a plurality of flame ports(e.g., at or facing central combustion zone). Flame portsmay be distributed, for example, along the circumferential direction C, about central combustion zone. Gaseous fuel is thus flowable from mixing chamberwithin burner bodyinto central combustion zonethrough flame ports. Flame portsmay also be oriented such that the gaseous fuel flows in a swirling pattern from flame portsinto central combustion zone. In various embodiments, flame portsmay be configured with similar angular extensions and directions as flame ports, such as providing a similar swirl component from burner bodies,.

In certain embodiments, burner bodyincludes an inner side walland an outer side wall. Inner side wallmay extend around central combustion zone(e.g., along the circumferential direction C). Flame portsmay be formed on or extend through inner side wall(e.g., substantially along the radial direction R, or additionally, along radial direction R and circumferential direction C, between mixing chamberand central combustion zone). Outer side wallmay extend around inner side wall(e.g., along the circumferential direction C). Outer side wallmay also be spaced from inner side wall(e.g., along the radial direction R). Mixing chambermay be defined and positioned between inner and outer side walls,(e.g., along the radial direction R, within annular burner body).

Burner bodyis open at central combustion zone. For example, no portion or component of burner bodymay extend (e.g., inward or otherwise along the radial direction R) into central combustion zone. In some embodiments, no fuel-providing structure extends into the central combustion zone. Top panelmay be exposed through burner bodyat central combustion zone. Specifically, a circumferentially bounded portion of top panel(e.g., bounded by burner body) may be exposed along the axial direction A. In such a manner, spills from utensils above burner assemblymay flow through central combustion zoneto top panel, and such spills may pass through burner assemblywithout contacting burner assemblyat central combustion zone. Staining of burner bodymay be reduced or limited by allowing spills to pass through burner bodyat central combustion zone.

Burner bodymay include an annular burner baseand an annular burner head. Burner baseincludes one or more inlet passagesconfigured to receive a flow of gaseous fuel from a mixing tube, such as a vertical Venturi mixing tube. Burner headmay be positioned on burner baseto form mixing chamberof burner body. Thus, burner basemay form a bottom wall of mixing chamber, and burner headmay form a top wall of mixing chamber. Burner baseor burner headmay be formed of a cast metal, such as cast iron or cast aluminum alloy.

Top panelmay also be continuous or imperforate directly below central combustion zone,. Thus, spills passing through central combustion zone,may collect on top paneland not flow through top panel. A user may easily access and clean such spills on top panelby removing burner body,from top panel. In such a manner, burner assemblymay facilitate cleaning of spills from utensils positioned over burner assembly.

In some embodiments, mixing tube,extends through top panel(e.g., along the axial direction A) toward fuel manifoldfrom respective burner body,. For instance, top panelmay form openings through which mixing tube,is extendable into fluid communication with a fuel manifold.

When assembled to the cooktop appliance, fuel manifoldis positioned beneath top panel(e.g., along axial direction A). Thus, fuel manifoldmay be positioned at or proximate to a bottom surface of the top paneland burner body,may be positioned at or proximate to a top surfaceof the top panel. Burner body,is fluidly coupled to fuel manifoldsuch that the gaseous fuel is flowable from fuel manifoldinto respective mixing chambers,. For example, fuel manifoldhas an outlet passage. The gaseous fuel is flowable from fuel manifoldthrough outlet passageinto mixing chamberof burner body. In another example, fuel manifoldhas an outlet passage. The gaseous fuel is flowable from fuel manifoldthrough outlet passageinto mixing chamberof burner body.

As shown, burner body,have a respective vertical mixing tube,. Mixing tube,may form a Venturi mixing tube. Embodiments of the mixing tube have a respective inlet,to a flow passage in fluid communication with respective mixing chambers,through respective openings,. Burner body,may include a plurality of mixing tubes,positioned at different locations along the circumferential direction C. For instance, the plurality of mixing tubes,may be substantially evenly spaced apart from one another. In various embodiments, the burner body includes one, or two or more mixing tubes, such as three mixing tubes, or other appropriate quantity to provide a fuel-air mixture to respective mixing chambers.

Fuel manifoldincludes a bodyforming a first fuel passageand a second fuel passage. The first fuel passageextends from an inlet openingto an outlet opening. An outlet fuel nozzleis positioned at the outlet opening. The outlet fuel nozzleis configured to direct a flow of gaseous fuel toward the mixing tubeat the burner body. In various embodiments, the outlet fuel nozzleis extended in vertical orientation from the outlet openingtoward the mixing tube inletat the mixing tube. Outlet openingmay be positioned at different locations along the circumferential direction C. For instance, a plurality of outlet openingsmay be substantially evenly spaced apart from one another. In various embodiments, the fuel manifoldmay include two or more outlet passages, such as three outlet passages, or a quantity and position corresponding to a quantity of vertical mixing tubes, such as to provide a gaseous fuel through the outlet openingto a respective vertical mixing tube.

The second fuel passageextends from an inlet openingto an outlet opening. An outlet fuel nozzleis positioned at the outlet opening. The outlet fuel nozzleis configured to direct a flow of gaseous fuel toward the mixing tubeat the burner body. In various embodiments, the outlet fuel nozzleis extended in vertical orientation from the outlet openingtoward the mixing tube inletat the mixing tube. Outlet openingmay be positioned at different locations along the circumferential direction C. For instance, a plurality of outlet openingsmay be substantially evenly spaced apart from one another. In various embodiments, the fuel manifoldmay include one, or two or more outlet passages, such as three outlet passages, or a quantity and position corresponding to a quantity of vertical mixing tubes, such as to provide a gaseous fuel through the outlet openingto a respective vertical mixing tube.

A fuel nozzle may be positioned at and oriented towards inletof body. In particular, the fuel nozzle may be mounted to the bodysuch that the fuel nozzle is spaced from fuel passage(e.g., along the radial direction R). The fuel nozzle may be connected to a supply line for gaseous fuel, such as propane or natural gas, and the gaseous fuel may flow from the fuel nozzle through fuel passageand outlet openingof body.

One or more first postsextends from body. Postis configured to mount and support a heat sink plate. The heat sink plateis a separate and separable structure from the body. In various embodiments, postis configured to receive a fastener extending into the postto affix the heat sink plateto the post. Postmay include an opening into which the fastener is extendable. The opening may form a threaded interface configured to receive the fastener including a threaded shank, such as, but not limited to, a screw, a bolt, a tie rod, etc. In various embodiments, postextends along axial direction A and forms a cavity or gap between the heat sink plateand the body.

Embodiments of the fuel manifoldmay advantageously and beneficially reduce a mass and weight of material in contrast to known fuel manifolds. Additionally, embodiments provided herein allow for simple construction, such as via die casting, additive manufacturing, machining, or combinations thereof. Various embodiments of the fuel manifoldinclude the bodyand postsforming a unitary, monolithic structure. For instance, various embodiments of burner assemblyinclude the fuel manifoldforming a unitary, monolithic structure separate from the heat sink plate, top panel, and burner body,.

The gaseous fuel is received through inlet openings,into respective fuel passages,and pushed out through respective outlet openings,. For instance, fuel passages,may be formed fluidly segregated from one another. The gaseous fuel egressing the outlet opening,may entrain air from the space between the outlet opening,and respective mixing tube inlet,, and the gaseous fuel may mix with the entrained atmospheric air within vertical mixing tube,. The mixture of the gaseous fuel and air may mix at respective fluidly-coupled mixing chambers,and egress through respective fluidly-coupled flame ports,.

Outlet openings,may be distributed or sized to facilitate uniform flow of the gaseous fuel into inlet openings,. For example, outlet openings,may be, for example, uniformly distributed about central combustion zone,.

The heat sink plateis positioned and retained by postsrelative to a portion of top panel, such as radially inward from annular burner body, to advantageously prevent damage or otherwise manage heat generated within combustion zone. For instance, legsmay position the heat sink platealong the circumferentially bounded portion of the top panelbelow the plurality of flame ports. Thus, heat absorbed at the portion of the top panelvertically or axially aligned with the central combustion zonemay be advantageously reduced by the heat sink plate.

In various embodiments, heat sink plateis positioned between the annular burner bodyand above fuel manifold body. Thus, relative to axial direction A, legsat bodyallow the heat sink plateto be disposed below the burner body,and above the fuel passage,.

In various embodiments, the heat sink plateis formed from a thermally conductive metal material (e.g., aluminum or steel, including alloys thereof). In some embodiments, the conductive heat sink plateextends (e.g., upward along the axial direction A) from the fuel passageto bottom surface of the top panel. Furthermore, postsoffset the heat sink platefrom the body. Thus, a base or bottom of conductive heat sink plateis disposed from body, such as to form the cavity or gap extending vertically therebetween.

Referring now to, flame portsof the outer burner bodyare positioned at a height along the axial direction A above the cooktop, such as depicted at reference first height. Flame portsof the inner burner bodyare positioned at a height along the axial direction A above the cooktop, such as depicted at reference second height. In various embodiments, second heightmay reference an uppermost portion of flame portsalong the axial direction A. Second heightof flame portsat the inner burner bodyis below first heightof flame portsat the outer burner body. In some embodiments, second heightof flame portsat the inner burner bodyis below first heightreferencing a lowermost portion along axial direction A of flame portsat the outer burner body. Accordingly, flame portsof the inner burner bodyare positioned at a height along the axial direction A above the cooktop (e.g., above top panel) that is below that of flame portsof the outer burner body.

A height separation, such as a difference between heights,, may facilitate an increased distance to diffuse heat from the inner burner bodybefore impinging on the bottom surface of cookware at the burner assembly. In some embodiments, the height separation is approximately twelve (12) millimeters, or approximately 0.5 inches, or greater, along the axial direction A. In still some embodiments, a ratio of the height separation to an axial dimension of flame portsis at least 2:1, such as the height separation is at least double the axial dimension of the flame ports. In still some embodiments, a ratio of the height separation to an axial dimension of flame portsis at least 3:1, or at least 5:1. The height separation may provide additional distance to diffuse combusted gases from the inner burner body. The height separation may facilitate diffusion of combusted gases to generate a more even heat at low heat settings.