Abstract:
A method for modifying an open-top burner system to a radiant burner system involves providing a stovetop having an open top burner system which includes a grate, burner head, and a venturi burner. The venturi burner includes an open top annular channel about a central opening. Further provided are a central hole plug, an emitter, and a radiant burner head assembly. To modify the stovetop, the grate and burner head are removed from the stovetop and the central plug is used to block airflow through the central opening. The radiant burner head assembly is next positioned over the venturi burner and the emitter is positioned over the radiant burner head assembly. This series of steps thereby converts the assembly from a traditional open-top burner system to a radiant burner system. A kit may be provided to facilitate the process.

Description:
CROSS-REFERENCE 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/492,110, filed Jun. 1, 2011, the entirety of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a method of converting a gas burner from an open top arrangement to an infrared radiant burner system, and the resulting apparatus. 
     BACKGROUND 
     Gas fired cooking ranges have achieved wide acceptance in both residential and commercial kitchens. A known design for gas fired cook tops in ranges includes separate burner assemblies for each cooking location, with each burner assembly including a venturi and a burner head having gas-emitting orifices. A grate or other surface is often positioned above the burner head and venturi to provide a surface for pots, pans, other cooking vessels, or food products. 
     Factors such as flame intensity and efficiency, burner assembly cleanability, and fuel consumption efficiency are important to both residential and commercial installations. The time required for completing a food course, including initial preparation time for heating and actual cooking time, can be reduced by efficient burner performance and heat transfer to the cooking vessel atop the burner. 
     This arrangement is traditionally considered inefficient as the system heats the air around the grate, eventually transferring heat to the pot, pan, or food product placed thereon. A more efficient system is that described in U.S. Pat. No. 7,726,967, that describes a gas-fed infrared burner. Gas-fed infrared burners are more efficient than similar open-top gas-fired burners, and therefore their use reduces energy consumption while improving cooking times. 
     An infrared radiant burner stovetop assembly is an expensive replacement for an open-top gas burner and may require substantial modification of the kitchen, stovetop, and cooking arrangement. 
     Therefore, there is a need in the art for an improved method and apparatus for replacing an open-top gas burner arrangement with an infrared radiant burner arrangement. 
     SUMMARY 
     Described herein is a method for modifying an open-top burner system to a radiant burner system. This modification is achieved by providing a stovetop having an open top burner system that includes a grate, burner head, and a venturi burner. The venturi burner includes an open top annular channel about a central opening. Further provided are a central hole plug, an emitter, and a radiant burner head assembly. To modify the stovetop, the grate and burner head are removed from the stovetop and the central plug is used to block (substantially or entirely) airflow through the central opening of the venturi burner. The radiant burner head assembly is next positioned over the venturi burner and the emitter is positioned over the radiant burner head assembly. This series of steps converts the assembly from a traditional open-top burner system to a radiant burner system. 
     According to various further embodiments, the radiant burner head assembly may include a plenum and a perforated member. The radiant burner head assembly may further include a spacer for separating two or more perforated members. According to another embodiment, the stovetop may include a support for supporting the grate that is used to support the emitter. 
     Also disclosed is an apparatus or kit for converting a traditional open top burner system to a radiant burner system. The traditional open top burner system generally includes a venturi burner with a central opening, a burner head, and a grate. The apparatus or kit includes a plug for blocking secondary air flow through the central opening, a radiant burner head assembly that is sized to rest on the venturi burner, and an emitter that replaces the grate. 
     According to various further embodiments, the radiant head assembly may include a plenum with an opening for fitting over the venturi burner. The radiant head assembly may also include one or more perforated members and one or more support members. The support members may be positioned between adjacent perforated members. According to yet another embodiment, the radiant burner assembly may include baffle and burner assemblies. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of a gas cooking range; 
         FIG. 2  is a perspective view of one embodiment of a duel burner head unit; 
         FIG. 3  is an exploded partial view of one embodiment of an open top burner system; 
         FIG. 4  is an exploded partial view of one embodiment of a radiant burner system; 
         FIG. 5  is a side cutaway or cross-section of one embodiment of the assembled radiant burner system; 
         FIG. 6  is an exploded view of one embodiment of the radiant burner head assembly; 
         FIG. 7  is a side cutaway or cross-section of one embodiment of the radiant burner head assembly and an open top burner assembly in a dual burner head unit. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , numeral  100  designates a gas cooking range having a cooktop  102  with multiple cooking locations  104  (e.g., six in the illustrated embodiment, 3 front and 3 back) with associated burner heads. In one embodiment, pairs of burner heads are formed by burner head assemblies  106  (see  FIG. 2 ), but each burner head could be formed and fed with gas on an individual basis. Range  100  further includes an oven chamber  118  beneath the cooktop area. The range  100  may be a commercial range or a residential range, taking on a variety of configurations, of which  FIG. 1  is merely exemplary. 
     Range  100  includes a gas circuit for supplying combustible gas to each burner head and to an oven burner assembly (not shown). The gas circuit includes a plurality of flow control valves  110  provided for initiating, terminating, and controlling the rate of gas flow to cooking locations  104  on cook top  102 . Various valve configurations and gas flow circuits could be used. Illustrated range  100  is supported on casters  112 , by which range  100  can be moved a short distance to clean the area around the range. However, embodiments without casters are contemplated. 
     Exemplary burner head assembly  106  includes a first burner head  120  and a second burner head  122  at which combustion of gaseous fuel occurs. A single piece, monolithic casting  124  forms a first venturi  126  associated with or feeding a first burner head base  128  and a second venturi  130  associated with or feeding a second burner head base  132 . The burner head base  128 ,  132  may be alternatively referred to as a venturi burner. First venturi  126  and second venturi  130  provide a flow of gas and primary combustion air for combustion at first and second burner heads  120 ,  122 , respectively, in front and back locations, respectively, on cook top  102 . First and second gas receivers  134 ,  136 , are provided on first venturi  126  and second venturi  130 , respectively. Each receiver  134 ,  136  is aligned and/or connected with a different control valve  110  to receive gas therefrom when the control valve  110  is opened to allow gas to flow therethrough. Receivers  134 ,  136  also admit a flow of ambient air to mix with the combustible gas in first venturi  126  and second venturi  130  to provide a combustible mixture to burner heads  106 ,  122 . 
       FIG. 2  illustrates burner head assembly  106  in a partial state of disassembly. Each burner head base  128 ,  132  may be a substantially annular body defining an open top annular channel  138  between an inner wall  140  and an outer wall  142 . Annular channel  138  of burner head base  128  is visible in  FIG. 2 . Prior to conversion, burner head cover  144  may be provided on each burner head base  128 ,  132 , with cover  144  on burner head base  132  being shown in  FIG. 2 . Each cover  144  has a plurality of gas-emitting orifices  146  therein through which a mixture of combustible gas and primary combustion air is emitted. The inner wall  140  further surrounds a central opening  141  that provides an upward secondary air flow to the combustion space. This central opening  141  may include a restrictor plate (shown as  143  for head  122 ) that meters or regulates air flow. 
       FIG. 3  illustrates an exploded view of cooking locations  104  on cook top  102 . Positioned above each burner head assembly  106  is a grate  148  that allows for placement of a cooking apparatus (not shown) above the burner assembly  106 . The cooking apparatus may be a pot, pan, rotisserie, or other apparatus useful in the cooking of food products (not shown). Alternatively, food may be positioned directly on or above the grate  148 , foregoing the use of cooking apparatus. As further shown in  FIG. 3 , the grate  148  may be positioned on supports  150 ,  152  sized to support grate  148  over the burner assembly  106 . As shown in  FIG. 2 , burner head cover  144  is positioned on burner head base  132  to evenly distribute a flame for cooking on grate  148 . In order to convert a given open top burner to a radiant burner system, the grate  148  and burner head cover  144  are removed from the applicable cooking location  104 . 
     Conversion of the burner system is further illustrated in  FIG. 4 . As shown, the grate  148  and burner head cover  144  have been removed. Any regulating restrictor plate over the central opening  141  is also preferably removed, along with any associated igniter that is secured to the restrictor plate. The central opening  141  is plugged with a center hole plug  154  that prevents or severely restricts the ability of secondary air to flow upward through the opening  141 . Next, a radiant burner head assembly  156  is positioned on the burner head base  132  so that gas flow is directed upward into and through the radiant burner head assembly  156 . Finally, an emitter  158  is positioned on the supports  150 ,  152 , overlapping or covering the radiant burner head assembly  156 . 
       FIG. 5  illustrates a side cutaway of the completed radiant burner assembly. As shown in this figure, the center hole plug  154  covers the central opening  141  of the burner head base  132 , preventing or limiting airflow therethrough. In the illustrated embodiment, the center hold plug includes a cylindrical wall portion  155  having a bottom edge that rests upon an inner annular supporting ledge  153  of the burner head base, but other configurations are possible. The plug may be sized for a friction tight fit within the central opening  141 . The radiant burner head assembly  156  is positioned on the burner head base  132  so that gas flow through the burner head base  132  enters the radiant burner head assembly  156 . Finally, the emitter  158  has been positioned on the supports  150 ,  152  and surrounds the radiant burner head assembly  156  so that heat is transferred directly to the emitter  158 . 
       FIG. 6  illustrates an exploded view of the radiant burner head assembly  156 . The radiant burner head assembly  156  generally includes a plenum housing  160 , one or more perforated members  162  and one or more support members  164  (e.g., mounting members). As described in U.S. Pat. No. 7,726,967 to Best, herein incorporated by reference in its entirety, the perforated  162  and support members  164  may be stacked in alternating layers to dissipate heat to the emitter  158  ( FIG. 5 ). In accordance with the exemplary embodiment, each of the perforated members  162  may be fabricated from a nonwoven plate of high temperature metal alloy so that it defines a multiplicity of holes or perforations  56  that extend completely therethrough. 
     The plenum housing  160  generally consists of a base  166  including a burner opening  168 , which in the illustrated embodiment is sized and adapted to fit over and rest upon an outer annular supporting ledge  151  of the burner head base  132  ( FIG. 5 ). However, other configurations for supporting the plenum housing in relation to the burner head base could be used (e.g., feet that extend downward from the housing base and into the annular channel of the burner head base, or supports that extend radially outward from the plenum housing and engage some structure on the range top). In the illustrated embodiment, the plenum housing base  166  is surrounded by upward and outward sloping walls  170  defining a volume of the plenum. As further detailed in the Best &#39;967 patent, combustible gas and air are supplied into the plenum  160  and pass through one or more of the perforated members  162  before being combusted. This combustion serves to heat the emitter  158  ( FIG. 5 ) which in turn is used in cooking food items. 
     According to one embodiment, the perforated members  162  and support members  164  are connected to the plenum  160  to form a single piece radiant burner assembly  156 . This single unit provides a single piece for assembly and makes conversion easier. Alternatively, the perforated members  162  and support members  164  may be secured to one another and constitute a single sheaf that may be easily inserted into the plenum housing  160  during assembly and replaced if necessary during the life of the radiant burner system. It is also contemplated that in another embodiment the plug  154  could be supported within the plenum housing  160  (e.g., via connection to the housing  160 ) so as to automatically seal the opening  141  when the plenum housing  160  is placed upon the burner head base and/or support the plenum housing in relation the burner head base. In addition, the radiant burner head assembly may, for example, include an associated igniter mounted thereon (e.g., connected to an external surface of the housing  160 ) with associated wiring to be connected to the existing range wiring, or the radiant burner head assembly may simply include an igniter mount adapted to receive the pre-existing igniter of the open-top burner head assembly to properly position the igniter to ignite gases leaving the top of the radiant burner head assembly. 
       FIG. 7  illustrates a side cutaway of a cooktop  102  including a traditional open top burner system and a radiant burner system. As shown in this view, in converting the traditional system to a radiant system the burner head cover  144  and grate  148  have been removed. A center hole plug  154  has been placed in the central opening  141  of the burner head base  132  and a radiant burner head assembly  156  has been positioned over the burner head base  132 . Finally, an emitter  158  has replaced the grate  148 . 
     Variations and modifications of the described apparatus will be appreciated by those having skill in the art. For example, the radiant burner head  156  may vary in size or design according to the size, shape, and location of the burner head base  132  in the cooktop  102 . The emitter  158  may also vary in size, shape, or design according to the position of supports  150 ,  152 . The emitter  158  is preferably designed to engage the supports  150 ,  152  in the same manner as the grate  148  of the traditional open top burner system, therefore allowing for easy conversion between a traditional open top burner system and the preferred radiant burner system. Further, as described in Best &#39;967, the materials for the perforated members  162 , support members  164 , plenum  160 , and emitter  158  may vary according to demand. 
     It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.