Patent Publication Number: US-10330326-B2

Title: Gas burner assembly for a cooktop appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to cooktop appliances and gas burner assemblies for cooktop appliances. 
     BACKGROUND OF THE INVENTION 
     Gas burners are commonly used on the cooktops of household gas cooking appliances including e.g., range ovens and cooktops built into cabinetry. A significant factor of gas burners is their ability to withstand airflow disturbances in the surroundings, such as room drafts, rapid movement of cabinet doors, and most commonly oven door manipulation. For range appliances, manipulation of the oven door can be particularly troublesome because rapid opening and closing of the oven door can produce respective under-pressure and over-pressure conditions within the oven cavity. In turn, these pressure changes may cause rapid air expansion and/or contraction in the appliances. As a result, a large amount of air passes through or around the gas burners with e.g., rapid opening or closing of the oven door(s). Similarly for built-in cooktops, pressure changes due to rapid manipulation of surrounding cabinets may result in large amounts of airflow through or around the gas burners. 
     Such surges of air around the gas burners, due to pressure disturbances in the surroundings, are detrimental to the flame stability of the burners and may cause extinction of the flames. This flame stability problem is particularly evident in sealed gas burner arrangements, which lack an opening in the cooktop surface around the base of the burner so as to prevent spills from entering the area beneath the cooktop. 
     The inherent cause of this flame instability is the low pressure drop of the fuel/air mixture passing through the flame ports of a typical burner used on the cooktop of an appliance. Although there is ample pressure available in the fuel, the pressure energy is used to accelerate the fuel to the high injection velocity required for primary air entrainment. Relatively little of this pressure is available at the flame ports. A low pressure drop across the flame ports allows pressure disturbances propagating through the ambient to easily pass through the flame ports, momentarily drawing the flame towards the burner base and leading to thermal quenching and extinction. 
     A solution to the above-described problem is the use of a stability chamber as described e.g., in U.S. Pat. No. 5,800,159, commonly owned by the assignee of the present disclosure. The burner is able to maintain a simmer flame at both low and high settings so that the simmer flame can relight the flame at primary flame ports when needed. However, the use of stability chambers has been limited to gas burners having a centrally located burner throat that delivers fuel to the flame ports in a radially outward fashion. Thus, inwardly fired burners, such as inverted gas burners, cannot withstand pressure disturbances as well as traditional gas burners, and are more prone to flame extinction due to pressure disturbances. 
     Accordingly, an inwardly fired burner with features for maintaining a simmer flame would be welcomed within the technology. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present subject matter provided a gas burner assembly. The gas burner assembly includes a burner body that defines a plurality of inner flame ports at an inner sidewall of the burner body. Each inner flame port of the plurality of inner flame ports is positioned and oriented for directing a flow of fuel inwardly along a radial direction and at a swirl angle relative to the radial direction. The burner body further defines a stability chamber having a simmer flame outlet positioned at the inner sidewall of the burner body between a pair of the plurality of inner flame ports. The simmer flame outlet of the stability chamber is positioned closer to one of the pair of the plurality of inner flame ports than the other of the pair of the plurality of inner flame ports. A related cooktop appliance is also provided. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first exemplary embodiment, a gas burner assembly is provided. The gas burner assembly includes a burner body having an inner sidewall. The burner body defines a plurality of inner flame ports at the inner sidewall of the burner body. Each inner flame port of the plurality of inner flame ports is positioned and oriented for directing a flow of fuel inwardly along a radial direction and at a swirl angle relative to the radial direction. The burner body further defines a stability chamber having a simmer flame outlet positioned at the inner sidewall of the burner body between a pair of the plurality of inner flame ports. The simmer flame outlet of the stability chamber is positioned closer to one of the pair of the plurality of inner flame ports than the other of the pair of the plurality of inner flame ports. 
     In a second exemplary embodiment, a cooktop appliance is provided. The cooktop appliance includes a top panel. A gas burner assembly is positioned on the top panel. The gas burner assembly includes a burner body having an inner sidewall. The burner body defines a plurality of inner flame ports at the inner sidewall of the burner body. Each inner flame port of the plurality of inner flame ports is positioned and oriented for directing a flow of fuel inwardly along a radial direction and at a swirl angle relative to the radial direction. The burner body further defines a stability chamber having a simmer flame outlet positioned at the inner sidewall of the burner body between a pair of the plurality of inner flame ports along a circumferential direction. The simmer flame outlet of the stability chamber is positioned closer to one of the pair of the plurality of inner flame ports than the other of the pair of the plurality of inner flame ports along the circumferential direction. 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG. 1  provides a top, perspective view of a cooktop appliance according to an exemplary embodiment of the present subject matter. 
         FIG. 2  provides another top, perspective view of the exemplary cooktop appliance of  FIG. 1  with a gas burner assembly of the exemplary cooktop appliance shown removed from a panel of the exemplary cooktop appliance. 
         FIG. 3  provides a perspective view of a gas burner assembly according to an exemplary embodiment of the present subject matter. 
         FIG. 4  provides a perspective, section view of the exemplary gas burner assembly of  FIG. 3 . 
         FIG. 5  provides a top, plan view of a burner base of the exemplary gas burner assembly of  FIG. 3 . 
         FIG. 6  provides a top, plan view of a stability chamber of the burner base of  FIG. 5 . 
         FIG. 7  provides a side, section view of the exemplary gas burner assembly of  FIG. 3 . 
         FIG. 8  provides a side, section view of the burner base of  FIG. 5 . 
         FIG. 9  provides a perspective, section view of the burner base of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     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 or spirit 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. 
       FIG. 1  illustrates an exemplary embodiment of a cooktop appliance  100  as may be employed with the present subject matter. Cooktop appliance  100  includes a panel  102 , e.g., a top panel. By way of example, panel  102  may be constructed of enameled steel, stainless steel, glass, ceramics, and combinations thereof. 
     For cooktop appliance  100 , a utensil holding food and/or cooking liquids (e.g., oil, water, etc.) may be placed onto gas burner assemblies  200  at a location of any of gas burner assemblies  200 . Gas burner assemblies  200  can be configured in various sizes so as to provide e.g., for the receipt of cooking utensils (i.e., pots, pans, etc.) of various sizes and configurations and to provide different heat inputs for such cooking utensils. Gas burner assemblies  200  are supported on a top surface  104  of panel  102 , as discussed in greater detail below. Gas burner assemblies  200  provide thermal energy to cooking utensils above panel  102  by combustion of fuel below the cooking utensils. 
     A user interface panel  110  is located within convenient reach of a user of cooktop appliance  100 . For this exemplary embodiment, user interface panel  110  includes knobs  112  that are each associated with one of gas burner assemblies  200 . Knobs  112  allow the user to activate each burner assembly and determine the amount of heat input each gas burner assembly  200  provides to a cooking utensil located thereon. User interface panel  110  may also be provided with one or more graphical display devices that deliver certain information to the user such as e.g., whether a particular burner assembly is activated and/or the level at which gas burner assembly  200  is set. 
     Although shown with knobs  112 , it should be understood that knobs  112  and the configuration of cooktop appliance  100  shown in  FIG. 1  is provided by way of example only. More specifically, user interface panel  110  may 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. User interface panel  110  may include other display components, such as a digital or analog display device designed to provide operational feedback to a user. 
     Cooktop appliance  100  shown in  FIG. 1  illustrates an exemplary embodiment of the present subject matter. Thus, although described in the context of cooktop appliance  100 , the present subject matter may be used in cooktop appliances having other configurations, e.g., a cooktop appliance with one, two, or more additional burner assemblies. Similarly, the present subject matter may be used in cooktop appliances that include an oven, i.e., range appliances. 
       FIG. 2  provides another top, perspective view of cooktop appliance  100  with a gas burner assembly  200  of cooktop appliance  100  shown removed from panel  102  of cooktop appliance  100 . As may be seen in  FIG. 2 , gas burner assembly  200  is removable from panel  102  of cooktop appliance  100 . In certain exemplary embodiments, no mechanical fastening connects gas burner assembly  200  to panel  102 . Thus, gas burner assembly  200  may not be fastened to panel  102 , and a user may simply lift gas burner assembly  200  upwardly to remove gas burner assembly  200  from panel  102 , as shown in  FIG. 2 . In such a manner, a top surface  104  of panel  102  below gas burner assembly  200  may be easily accessible and cleanable. 
       FIG. 3  provides a perspective view of gas burner assembly  200 .  FIG. 4  provides a perspective, section view of gas burner assembly  200 . As shown, gas burner assembly  200  defines a vertical direction V. Gas burner assembly  200  includes a grate  210  configurable for supporting a cooking utensil, such as a pot, pan, etc. For example, grate  210  includes a plurality of tines or elongated members  212 , e.g., formed of cast metal, such as cast iron. The cooking utensil may be placed on elongated members  212  of grate  210  such that the cooking utensil rests on an upper surface  214  of elongated members  212 . Elongated members  212  of grate  210  may include an outer frame  216  that extends around or defines a perimeter of grate  210  and/or gas burner assembly  200 . Thus, outer frame  216  may be positioned at an outer portion  218  of grate  210 . Grate  210  may rest on panel  102  at outer frame  216  of grate  210 . Thus, a bottom surface of outer frame  216  may rest on top surface  104  of panel  102 . As shown, outer frame  216  of grate  210  may be square or rectangular in certain exemplary embodiments. Within outer frame  216 , elongated members  212  may define an inner passage  220  that extends vertically through grate  210 . Thus, fluid, such as air, may flow through grate  210  via inner passage  220 . 
     Gas burner assembly  200  may also include a burner cap  240  and a burner base  250 . Collectively, burner cap  240  and burner base  250  may be referred to as a burner body  202 . Burner cap  240  may define an opening  242 , which may be a hollow circular region within the center of burner cap  240 . Burner cap  240  may be mounted to grate  210 . In particular, burner cap  240  may be integrally formed with grate  210 , e.g., such that grate  210  and burner cap  240  are formed of or with a common piece of metal. For example, grate  210  and burner cap  240  may be cast as a single continuous piece of metal, such as cast iron or aluminum. 
     Burner base  250  may be mounted to burner cap  240 , e.g., with fasteners (not shown). Thus, burner cap  240  and burner base  250  may be separate pieces of metal, such as cast metal, that are mounted to each other to form a gas burner. However, according to alternative embodiments, the gas burner assembly  200  may be formed from a single piece of material or from more than two pieces of material. 
     Burner cap  240  and burner base  250  may be supported by grate  210  such that burner cap  240  and burner base  250  are suspended from grate  210  above panel  102  ( FIG. 1 ). In particular, burner cap  240  and burner base  250  may be positioned over and spaced from panel  102 , e.g., along the vertical direction V. Thus, spilled fluid from a cooking utensil on gas burner assembly  200  may be easily cleanable below burner body  202  and conductive heat transfer between burner body  202  and panel  102  may be limited by the vertical gap between burner body  202  and panel  102 . 
     Burner body  202  defines a circumferential direction C, an axial direction A, and a radial direction R. Turning now to  FIGS. 4 and 5 , burner base  250  includes an inner sidewall  252  and an outer sidewall  254 . In certain exemplary embodiments, inner sidewall  252  and/or outer sidewall  254  may be arcuate and extend along the circumferential direction C. As shown, inner sidewall  252  defines a plurality of primary or inner flame ports  256  spaced apart from one another along the circumferential direction C on inner sidewall  252 . Inner sidewall  252  also defines a simmer flame port  258  (e.g., an outlet of stability chamber  280 ). More specifically, simmer flame port  258  may be disposed between two primary flame ports  256  along the circumferential direction C on inner sidewall  252 . Outer sidewall  254  is spaced apart from inner sidewall  252  along the radial direction R such that a fuel chamber  260  is positioned between outer sidewall  254  and inner sidewall  252  along the radial direction R. 
     It should be understood that, in some exemplary embodiments, a bottom portion of burner base  250  may be spaced apart from burner cap  240  along the axial direction A. Thus, in some embodiments, fuel chamber  260  may be positioned between the inner and outer sidewalls  252 ,  254  along the radial direction R, and between the burner cap  240  and the bottom portion of the burner base  250  along the axial direction A. 
     As may be seen in  FIG. 4 , each primary flame port of primary flame ports  256  has a width W 1 , e.g., along a circumferential direction. Similarly, simmer flame port  258  of stability chamber  280  also having a width W 2 , e.g., along the circumferential direction C. The width W 2  of simmer flame outlet  258  is greater than the width W 1  of primary flame ports  256 . Thus, fuel may flow more slowly from simmer flame port  258  than primary flame ports  256  during operation of gas burner assembly  200 . 
     Burner base  250  defines a combustion chamber  259 , which may be a hollow circular region within the center of burner base  250 . Inner sidewall  252  may surround combustion chamber  259  along the circumferential direction C. As such, air may flow through combustion chamber  259  along the axial direction A, and the air may mix with a gaseous fuel/air mixture exiting primary flame ports  256  and simmer flame port  258 . Gas burner assembly  200  may also include an igniter  130  ( FIG. 2 ) positioned at or within the combustion chamber  259  to ignite the gaseous fuel/air mixture flowing into combustion chamber  259  via simmer flame port  258  and/or primary flame ports  256 . 
     Burner base  250  may also include a baffle  270  ( FIG. 4 ) positioned between inner sidewall  252  and outer sidewall  254  along the radial direction R within fuel chamber  260 . Baffle  270  may extend between an inner surface  272  and an outer surface  274  along the radial direction R. Inner surface  272  of baffle  270  may face inner sidewall  252  along the radial direction R, and outer surface  274  of baffle  270  may face outer sidewall  254  along the radial direction R. 
     Baffle  270  may define a plurality of recesses  276 . Recesses  276  may be spaced apart from one another along the circumferential direction C on baffle  270 . Accordingly, fuel chamber  260  may extend from inner sidewall  252  to outer sidewall  254  through recesses  276  formed on baffle  270 . It should be appreciated that baffle  270  may promote a uniform pressure within the burner base  250  proximate primary flame ports  256  in order to produce uniform flame lengths around inner sidewall  252 . 
       FIG. 5  provides a top, plan view of burner base  250 .  FIG. 6  provides a top, plan view of a stability chamber  280  of burner base  250 . As shown in  FIGS. 5 and 6 , burner base  250  defines, at least in part, stability chamber  280 . Stability chamber  280  extends outwardly from simmer flame port  258  along the radial direction R, e.g., such that stability chamber  280  extends from inner sidewall  252  into burner base  250  along the radial direction R. As shown, stability chamber  280  may be defined, at least in part, by an end wall  282  positioned within burner base  250 . More specifically, end wall  282  may be positioned between inner sidewall  252  and outer sidewall  254  along the radial direction R. 
     Stability chamber  280  may be further defined, at least in part, by a pair of opposing walls  300 ,  302  positioned within burner base  250  and spaced apart from one another along the circumferential direction C. Each opposing wall  300 ,  302  may extend outwardly from simmer flame port  258 , e.g., along the radial direction R. For example, each opposing wall  300 ,  302  may extend outwardly from simmer flame port  258  to end wall  282  along the radial direction R. Stability chamber  280  may be further defined between burner cap  240  and a bottom portion of burner base  250  along the axial direction A. Accordingly, in some exemplary embodiments, stability chamber  280  may be positioned between simmer flame port  258  and end wall  282  along the radial direction R, between the pair of opposing walls  300 ,  302  along the circumferential direction C, and between burner cap  240  and the bottom portion of burner base  250  along the axial direction A. In addition, stability chamber  280  may also be positioned adjacent to an inlet  290  of fuel chamber  260 . As will be discussed below in more detail, gaseous fuel may enter fuel chamber  260  at inlet  290 . 
     End wall  282  may, at least in part, define a first inlet port  310  and a second inlet port  312 . First and second inlet ports  310 ,  312  may extend between fuel chamber  260  and stability chamber  280 . Thus, fuel chamber  260  may be in fluid communication with stability chamber  280  via first and second inlet ports  310 ,  312 . In an alternative embodiment, opposing wall  300  may, at least in part, define first inlet port  310 , and opposing wall  302  may, at least in part, define second inlet port  312 . More specifically, opposing wall  300  and end wall  282  may each define a portion of first inlet port  310 , whereas opposing wall  302  and end wall  282  may each define a portion of second inlet port  312 . 
     Primary flame ports  256  assist with combusting fuel in a swirling pattern at or within combustion chamber  259  during operation of gas burner assembly  200 . For example, primary flame ports  256  may be positioned and oriented for directing fuel from fuel chamber  260  inwardly along the radial direction R into combustion chamber  259 . Thus, fuel exiting primary flame ports  256  may have a radial velocity component that is directed towards a center of burner body  202  (or combustion chamber  259 ). Primary flame ports  256  may also be positioned and oriented for directing fuel from fuel chamber  260  as at a swirl angle α relative to the radial direction R. The swirl angle α may be defined between a central axis of each primary flame port  256  and the radial direction R, e.g., in a plane that is perpendicular to the axial direction A. 
     The swirl angle α may be selected such that fuel from primary flame ports  256  is angled away from the center of burner body  202  (or combustion chamber  259 ), e.g., in a swirling pattern around the center of combustion chamber  259 . In certain exemplary embodiments, the swirl angle α may be no less than five degrees and no greater than thirty-five degrees. As a particular example, the swirl angle α may be about twenty degrees. As used herein, the term “about” means within five degrees of the stated angle when used in the context of swirl angles. 
     Simmer flame port  258  may be positioned on inner sidewall  252  in a manner that facilities operation of the simmer flame port  258  and/or stability chamber  280  while accounting for the swirl angle α of primary flame ports  256 . In particular, simmer flame port  258  may be positioned between a first flame port  320  of primary flame ports  256  and a second flame port  322  of primary flame ports  256 , e.g., along the circumferential direction C. Simmer flame port  258  may be directly between first and second flame ports  320 ,  322  such that first and second flame ports  320 ,  322  are immediately adjacent simmer flame port  258  and no other flame ports of primary flame ports  256  are between simmer flame port  258  and first and second flame ports  320 ,  322 , e.g., along the circumferential direction C. 
     Simmer flame port  258  may be offset towards first flame port  320 , e.g., along the circumferential direction C. Thus, simmer flame port  258  (e.g., a center of simmer flame port  258 ) may be positioned closer to first flame port  320  than to second flame port  322  (e.g., the center of simmer flame port  258 ) along the circumferential direction C. As an example, simmer flame port  258  may be positioned no less than two millimeters and no more than twenty millimeters closer to first flame port  320  than to second flame port  322  along the circumferential direction C. Such positioning of simmer flame port  258  relative to first and second flame ports  320 ,  322  may facilitate operation of simmer flame port  258  in view of the swirl angle α of first and second flame ports  320 ,  322 . In particular, the swirl angle α of second flame port  322  may be selected such that second flame port  322  orients fuel from fuel chamber  260  towards simmer flame port  258  along the circumferential direction C during operation of gas burner assembly  200 , as shown in  FIG. 6 . Similarly, the swirl angle α of first flame port  320  may be selected such that first flame port  320  orients fuel from fuel chamber  260  away simmer flame port  258  along the circumferential direction C during operation of gas burner assembly  200 , as shown in  FIG. 6 . Thus, a simmer flame at simmer flame port  258  may more easily relight fuel from both first and second flame ports  320 ,  322  relative to simmer flame ports positioned equidistantly from first and second flame ports  320 ,  322 . In addition, such positioning of simmer flame port  258  relative to first and second flame ports  320 ,  322  may reduce coalescence between the simmer flame at simmer flame port  258  and a flame at first flame port  320 , e.g., during high fuel flow rates from primary flame ports  256 . 
     Referring now to  FIG. 7 , grate  210  includes features for supplying fuel to burner body  202 , e.g., to fuel chamber  260 . Grate  210  defines an internal fuel passage  230 , e.g., configured for directing fuel through grate  210  to burner base  250 . It should be appreciated that grate  210  may be constructed of or with any suitable material. For example, grate  210  may be constructed of or with a single piece of cast metal. In particular, grate  210  may be formed of cast iron with the internal fuel passage  230  formed within grate  210  using disposable cores during the casting process. 
     Internal fuel passage  230  extends between an inlet  232  and an outlet  234 . Inlet  232  is positioned at or adjacent outer portion  218  of grate  210 . Conversely, outlet  234  is positioned at or adjacent central portion  222  of grate  210 . Thus, internal fuel passage  230  may extend between outer portion  218  and central portion  222  of grate  210  within one of elongated members  212  of grate  210 . In addition, at least a portion of internal fuel passage  230  may be positioned above (e.g. higher along the vertical direction V that is parallel to the axial direction A) simmer flame port  258  and/or each primary flame port  256 . Alternatively, or in addition to, internal fuel passage  230  may be positioned adjacent stability chamber  280 . 
     Outlet  234  is contiguous with, or adjacent to, fuel chamber  260 . More specifically, outlet  234  of internal fuel passage  230  is positioned above inlet  290  of fuel chamber  260  along the vertical direction V. Thus, fuel from internal fuel passage  230  may flow into fuel chamber  260  via outlet  234 . Fuel may then exit fuel chamber  260  at primary flame ports  256 . Fuel may also exit the fuel chamber  260  at the first and second inlet ports  310 ,  312  and subsequently enter stability chamber  280  where the fuel flows to simmer flame port  258 . 
       FIG. 8  provides a side, section view of burner base  250 .  FIG. 9  provides a perspective, section view of burner base  250 . As shown in  FIG. 8 , stability chamber  280  extends between a top portion  330  and a bottom portion  332 , e.g., along an axial direction A. First and second inlet ports  310 ,  312  may be positioned at or adjacent top portion  330  of stability chamber  280 . For example, first and second inlet ports  310 ,  312  may also be positioned above simmer flame port  258  along the axial direction A. Thus, simmer flame port  258  may be positioned between first and second inlet ports  310 ,  312  and bottom portion  332  of stability chamber  280  along the axial direction A. 
     As shown in  FIGS. 7 and 9 , a top wall  340  of burner body  202  (e.g., burner cap  240 ) at top portion  330  of stability chamber  280  may slope downwardly along the radial direction R between first and second inlet ports  310 ,  312  and simmer flame port  258 . Such sloping of top wall  340  may induce a downward (e.g., along the vertical direction V) velocity component to fuel exiting stability chamber  280  at simmer flame port  258  during operation of gas burner assembly  200 , as shown in  FIG. 9  with the solid black arrows at simmer flame port  258 . The downward velocity component of fuel from stability chamber  280  may reduce coalescence between the simmer flame at simmer flame port  258  and a flame at first flame port  320 , e.g., during high fuel flow rates from primary flame ports  256 . 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.