Patent Publication Number: US-11644197-B2

Title: System and method for bimodal air control in a kettle-style grill

Description:
BACKGROUND 
     The present invention relates to outdoor grilling and smoking solutions and, more particularly, to a novel system for enabling bimodal air control in a kettle-styled grill designed for use with charcoal. 
     Kettle-styled grills designed for use with a charcoal briquette fuel source, such as a typical Weber® grill, are relatively inexpensive and ubiquitous in the marketplace. As one of ordinary skill in the art of kettle-styled grills would recognize, air flow is usually controlled manually through lower dampers located in the bottom of the grill&#39;s kettle and, optionally, also through upper dampers located in the lid of the kettle. In addition to affecting air flow, the lower dampers may also be configured in a typical kettle-styled grill to agitate ash out of the kettle so that the ash may be collected in an ash can component located beneath the kettle. With skill and knowledge, the manual dampers (lower and/or upper) of a typical kettle-styled grill may be periodically adjusted and set by a user to control cooking temperature and/or smoke retention within the grill. 
     The skill and knowledge required by a kettle grill user to effectively manipulate and control air flow with manual dampers has led the industry to introduce various forced-air “add on” solutions designed to alleviate a user&#39;s need for mastery of the manual dampers. The prior art solutions, however, typically require that the kettle be modified with a “cut-out” and/or prevent a user from opting for manual damper control. 
     Therefore, there is a need in the art for a system and method that does not require modification of the grill&#39;s kettle and, additionally, enables a user to selectively alternate between a manual mode and an auto-mode for air control through the kettle. More specifically, there is a need in the art for a bimodal air control system in a kettle-styled grill. 
     SUMMARY 
     Exemplary embodiments of a system and method for bimodal air control in a kettle-style grill are disclosed. Certain embodiments are configured to be detachably mounted to the exterior of a kettle-styled grill such as, but not limited to, a Weber® charcoal grill. When mounted to the kettle-styled grill, a plenum-like component directs air flows to the interior of the grill&#39;s kettle via the kettle&#39;s lower body damper holes. A manually adjustable intake damper in the plenum component allows, restricts, or prevents a drawn ambient air flow into the plenum component. Separately, a forced air flow generated by a fan may also be provided into the plenum component. Ash that falls out of the kettle&#39;s damper holes falls through the plenum component and is captured in an ash receptacle that is removably mounted to the plenum component. In this way, embodiments of the solution do not require significant, if any, modification to the kettle-styled grill in order for the kettle-styled grill to use the bimodal air control system. Embodiments may also include temperature loop control of the fan. 
     An exemplary embodiment of a system for bimodal air control in a kettle-style grill having one or more damper holes in a lower portion of its kettle comprises 1) one or more positionable damper blades associated with the one or more damper holes in the lower portion of the kettle, each damper blade operable to be positioned such that it opens, restricts or closes off its associated damper hole; 2) a damper plenum having an open top and an open bottom, the damper plenum comprising a manually adjustable intake damper and a forced-air input port, wherein the manually adjustable intake damper is mechanically connected to the one or more positionable damper blades; 3) an ash receptacle component removably attached to the damper plenum; and 4) an air control unit comprising a variable speed fan. 
     The air control unit may further comprise a temperature sensor in electrical communication with an electronic controller configured to vary the speed of the fan. The electronic controller may be operable to apply a proportional-integral-derivative control algorithm and may also be configured to wirelessly communicate with a remote user device. 
     The damper plenum is configured to be mounted to the kettle-style grill such that the open top establishes a seal around an external area of the kettle that includes the one or more damper holes. The air control unit is attached to the damper plenum such that a forced air flow generated by the fan enters the damper plenum through the forced-air input port. And a drawn ambient air flow enters the damper plenum through the manually adjustable intake damper when the manually adjustable intake damper is in an open state. 
     Further to the exemplary embodiment, when the manually adjustable intake damper is in an open state, the one or more positionable damper blades are positioned in the kettle such that the one or more damper holes are closed off. Similarly, when the manually adjustable intake damper is in a closed state, the one or more positionable damper blades are positioned in the kettle such that the one or more damper holes are fully open. And, when the manually adjustable intake damper is in a partially open state, the one or more positionable damper blades are positioned in the kettle such that the one or more damper holes are partially restricted. Ash exiting the grill&#39;s kettle through the one or more damper holes is captured in the ash receptacle which is below the plenum. 
     Another exemplary embodiment of a system for bimodal air control in a kettle-style grill having one or more damper holes in a lower portion of its kettle comprises: 1) means for opening, restricting or closing off each of the one or more damper holes; 2) means for adjusting a drawn ambient air flow between fully open, fully closed, and partially open states; 3) means for adjusting a forced air flow; and 4) means for capturing ash expelled from the kettle. The means for adjusting the drawn ambient air flow operates simultaneously to adjust the means for opening, restricting or closing off each of the one or more damper holes. The drawn ambient air flow and the forced air flow both enter the kettle through the one or more damper holes. 
     When the means for adjusting the drawn ambient air flow between fully open, fully closed, and partially open states is in an open state, the means for opening, restricting or closing off each of the one or more damper holes operates to close off the one or more damper holes. Similarly, when the means for adjusting the drawn ambient air flow between fully open, fully closed, and partially open states is in a closed state, the means for opening, restricting or closing off each of the one or more damper holes operates to open the one or more damper holes. And, when the means for adjusting the drawn ambient air flow between fully open, fully closed, and partially open states is in a partially open state, the means for opening, restricting or closing off each of the one or more damper holes operates to restrict the one or more damper holes. 
     The means for adjusting a forced air flow comprises a temperature sensor in electrical communication with an electronic controller configured to vary a speed of a fan. The electronic controller may be operable to apply a proportional-integral-derivative control algorithm and may be configured to wirelessly communicate with a remote user device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an exemplary embodiment of a bimodal air control system for kettle-styled grills according to the solution; 
         FIG.  2    is an exploded view of the exemplary embodiment shown in  FIG.  1   ; 
         FIG.  3    illustrates the exemplary embodiment of  FIG.  1   , shown mounted to a kettle-styled grill; 
         FIG.  4    is a sectioned view of the  FIG.  3    illustration to illustrate the exemplary linkage between the novel system and the lower dampers of the kettle-styled grill; 
         FIG.  5    is a functional block diagram of the electrical components comprised within an exemplary embodiment of the solution for a bimodal air control system for kettle-styled grills; and 
         FIG.  6    is a flowchart illustrating an exemplary method for implementing bimodal air control in a kettle-styled grill using a bimodal air control system according to the solution. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments, aspects and features of the present invention encompass a system and method for bimodal air control in a kettle-styled grill (e.g., a Weber® grill designed for use with a briquette charcoal fuel). As one of ordinary skill in the art would understand and recognize, kettle-styled grills are primarily designed for manual manipulation of damper(s) to control an air flow through the kettle. 
     When a typical kettle-styled grill is used as intended, charcoal is placed in the kettle of the grill and ignited. A cooking grate is suspended within the kettle over the top of the charcoal. Thermal energy generated by the burning charcoal radiates upward toward the grate and cooks any food item placed thereon. To control temperature, rate of burn and smoke retention, kettle-styled charcoal grills usually rely on a somewhat crude, manual damper-type control. Some kettle-styled grills incorporate the damper on the top of a lid that mates to and over the lower kettle. Other kettle-styled grills, however, such as what is commonly known as a Weber® branded grill, incorporate a damper at the bottom of the kettle (often in addition to a damper on the lid of the kettle), thereby providing means for control of air directly to, and through, the burning charcoal. 
     As one of ordinary skill in the art would acknowledge, temperature, burn rate and smoke retention are all key parameters to be controlled when using a kettle-styled grill. And so, a user&#39;s experience and skill in leveraging the manual dampers may have a direct impact on the quality of the food being cooked. To improve control of the air flow in a kettle-styled grill, incorporation of an electric fan and temperature control loop may be used in lieu of the manual dampers. 
     Advantageously, embodiments of the solution are configured to detachably integrate to a kettle-styled grill having lower dampers in the kettle, without requiring modification of the kettle, and provide a user with a bimodal option to use the grill in a manual damper mode or in an auto-damper mode. When in the manual damper mode, the solution allows the user to rely on manual setting and manipulation of the lower dampers, while in the auto-damper mode the user may rely on an electric fan to force air through the lower damper holes in response to a temperature control loop. As will be better understood from the attached figures and the following description, embodiments of the solution may be integrated onto an existing kettle-styled grill without modifying the kettle (such as cutting a hole in the kettle) or rendering the lower dampers inoperable for ash removal and manual damping. 
     Turning now to the figures, an exemplary embodiment of a bimodal air control system  100  will be shown and described with collective reference to the illustrations in  FIGS.  1 - 5   . That is, each of the illustrations in  FIGS.  1 - 5    will be described simultaneously.  FIG.  1    generally illustrates an exemplary embodiment of a bimodal air control system  100  for kettle-styled grills according to the solution, while  FIG.  2    illustrates an exploded view of same.  FIGS.  3  and  4    illustrate the exemplary embodiment attached to a kettle-styled grill.  FIG.  5    is a functional block diagram of the electrical components comprised within a control system of an exemplary embodiment of the solution for a bimodal air control system for kettle-styled grills. 
     As should be apparent from the figures, the system  100  may be configured for mounting to the exterior of a kettle-styled charcoal grill. The bimodal air control system  100  may be mated/juxtaposed to the kettle  210  (see, for example,  FIGS.  3  and  4   ) of the grill such that the system  100  is positioned beneath and to the side of the kettle  210 . The mating flanges  125  of the damper plenum  107  may form a tight seal with the underside of the kettle. 
     The damper plenum  107  comprises a manually adjustable intake damper  115  that, when partially open, provides for a restricted intake of a drawn ambient air flow into the inner space of the damper plenum  107  (when the system  100  is in the manual damper mode) and, when fully closed, prevents inflow of ambient air into the damper plenum  107  while simultaneously preventing outflow of a forced air flow injected into the plenum  107  via a fan  105  (when the system is in the auto damper mode). Air flow into the plenum  107 , whether from a drawn ambient air flow or a forced air flow generated by fan  105  (or a combination of both), may exit the damper plenum  107  and enter the kettle  210  of the grill via open lower damper holes  215  (see  FIG.  4   ). 
     To be clear, manipulation of the adjustable intake damper  115  position via handle  119  corresponds with manipulation of damper blade  212  positions within the kettle  210  in order to open, restrict, or close off lower damper holes  215  in the kettle. The intake damper  115  may be mechanically connected to the damper blades  212  via connection  121  in order for adjustment of the intake damper  115  to correspondingly cause adjustment of the damper blades  212 . Generally, when intake damper  115  is fully closed, the lower damper holes  215  may be fully open (due to the position of damper blades  212 ) and the bimodal air control system  100  may be in auto-damper mode such that the only air flow into the damper plenum  107  (and subsequently into the kettle  210  via open lower damper holes  215 ) is a forced air flow attributable to electric fan  105 . And, when the intake damper  115  is fully open, the lower damper holes  215  may be fully closed (due to the position of damper blades  212 ) and the bimodal air control system  100  may be in shutdown mode such that no air is allowed to flow into the kettle  210  from damper plenum  107 . When the intake damper  115  is partially open, the lower damper holes  215  may also be partially open (due to the position of damper blades  212 ) to modulate air flow into the kettle  210  and the bimodal air control system  100  may be in manual damper mode. When the system  100  is in manual damper mode, a drawn ambient air flow may be pulled into the damper plenum  107  and, subsequently, into the kettle  210 . Depending on embodiment of the solution, the fan  105  may provide a supplemental forced air flow into the damper plenum  107  when the system  100  is in a manual damper mode. 
     As one of ordinary skill in the art of kettle-styled grills would understand, manipulation of the damper blades  212  within the kettle may agitate ash and cause the ash to exit the kettle through lower damper holes  215 . The ash may fall gravitationally through the damper plenum  107  and collect in ash can or ash receptacle  109 . The ash can  109  may be releasably connected to the lower portion of the damper plenum  107  via a latch  111  or other means. In this way, a user of the system  100  may periodically empty collected ash by simply disconnecting the ash can  109  and without any need for disconnecting the damper plenum  107  and/or the entire system  100  from the grill. 
     Embodiments of the solution may leverage a controller  102  that includes a graphical user interface  101  or the like. The graphical user interface  101  may be local (such as depicted in the figure illustrations) and/or may be remotely displayed on a wirelessly connected user device. The controller  102 , along with a fan  105 , may be comprised within an air control unit defined by a housing  117  that is configured to mount on the outside of the damper plenum  107  and the kettle  210 . The controller  102  may include a processor, memory component(s), wireless transceiver, power supply, etc., as would be understood by one of ordinary skill in the art of electronic controllers. The controller  102  may have stored within its memory any one or more temperature control algorithms that, when executed by the processor, cause a speed adjustment to the fan  105 . That is, the controller  102  may be configured to receive temperature set points dictated by the user or, depending on embodiment, a temperature control algorithm may predefine a temperature set point without user input. The temperature setting informs the controller  102  in view of the temperature sensor  123  signal to vary the speed of the fan. The controller  102  may leverage a proportional-integral-derivative (“PID”) control algorithm, as would be understood by one of ordinary skill in the art of process control. In this way, the controller  102  may adjust the fan speed, and by extension the flow rate of a forced air flow into damper plenum  107 , in response to a temperature reading from temperature sensor  123 . 
     It is further envisioned that embodiments of the controller  102  may be configured to wirelessly communicate with a software application or the like running on a remote user device such as, but not limited to, a smartphone or pad device. In such embodiments, the user interface  101  may be partially comprised of a user interface on the remote user device. The user may leverage the remote user interface  101 , and/or the local user interface  101  (as shown in the figures), to adjust selection of the temperature control algorithm and/or monitor feedback data points (e.g., temperature, cooking time, alarms, etc.), as would be understood by one of ordinary skill in the art. 
     The one or more temperature control algorithms may rely on inputs from a temperature sensor  123  that may be placed on the cooking grate or elsewhere inside the kettle  210 . Depending on the particular embodiment, it is envisioned that the solution may leverage temperature sensor feedback from multiple temperature sensors positioned in multiple locations within and/or outside kettle  210 . The temperature sensor(s)  123  provides feedback to the controller  102  that, in turn, controls fan speed. By controlling the fan speed, the controller  102  may cause a cooking temperature to be maintained at a desired temperature setting since a forced air flow into the damper plenum through input port  113  will enter kettle  210  via lower damper holes  215  and affect cooking temperature. 
       FIG.  6    is a flowchart illustrating an exemplary method  300  for implementing bimodal air control in a kettle-styled grill using a bimodal air control system according to the solution. Beginning with block  305 , the controller  102  may recognize or determine the position of the intake damper  115 . In some embodiments, the controller  102  may rely on a user input to determine the intake damper  115  position while in other embodiments the controller  102  may be configured to receive a position sensor input to determine intake damper  115  position. 
     Returning to the method  300 , at decision block  310  the “yes” branch may be followed if the intake damper  115  is fully open. With the intake damper  115  fully open, the lower damper holes  215  in the kettle  210  may be fully closed. And so, the method  300  may arrive at block  325  and set the system  100  to shutdown mode. In shutdown mode, the controller  102  may cease actuation of fan  105  or, alternatively, may continue to force air through input port  113  into damper plenum  107  in order to improve thermal energy dissipation from kettle  210 . The method  300  returns to block  305  to monitor any changes in the position of intake damper  115 . If at decision block  310  it is determined that the intake damper  115  is not fully open, however, then the method  300  follows the “no” branch to decision block  315 . 
     At decision block  315  the “yes” branch may be followed if the intake damper  115  is fully closed. With the intake damper  115  fully closed, the lower damper holes  215  in the kettle  210  may be fully open. And so, the method  300  may arrive at block  330  and set the system  100  to auto-damper mode. In auto-damper mode, the controller  102  may modulate the speed of fan  105  based on an input from temperature sensor  123  and, in doing so, provide a forced air flow through input port  113  into damper plenum  107 . A drawn ambient air flow into damper plenum  107  may be prevented by virtue of the closed intake damper  115 . The forced air flow may enter kettle  210  through the fully open damper holes  215  in order to affect combustion and cooking temperature. The method  300  returns to block  305  to monitor any changes in the position of intake damper  115 . If at decision block  315  it is determined that the intake damper  115  is not fully closed, however, then the method  300  follows the “no” branch to decision block  320 . 
     At decision block  320  the “yes” branch may be followed if the intake damper  115  is partially open. With the intake damper  115  partially open, the lower damper holes  215  in the kettle  210  may also be partially open. And so, the method  300  may arrive at block  335  and set the system  100  to manual damper mode. In manual damper mode, the controller  102  may modulate the speed of fan  105  based on an input from temperature sensor  123  and, in doing so, provide a forced air flow through input port  113  into damper plenum  107  that supplements a drawn air flow into damper plenum  107  from partially open intake damper  115 . Alternatively, the controller  102  may shut off fan  105  such that the only air flow into damper plenum  107  is a drawn air flow through the partially open intake damper  115 . The air flow may enter kettle  210  through the partially open damper holes  215  in order to affect combustion and cooking temperature. The method  300  returns to block  305  to monitor any changes in the position of intake damper  115 . If at decision block  320  it is determined that the intake damper  115  is not partially open, however, then the method  300  follows the “no” branch and the method  300  returns. 
     A system and method for bimodal air control in a kettle-style grill according to the solution has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the disclosure. The described embodiments comprise different features, not all of which are required in all embodiments of a bimodal air control system according to the solution. Some embodiments of the solution utilize only some of the features or possible combinations of the features. Variations of embodiments of the solution that are described and embodiments of the solution comprising different combinations of features noted in the described embodiments will occur to persons of the art. 
     It will be appreciated by persons skilled in the art that a system and/or method for bimodal air control in a kettle-style grill according to the solution is not limited by what has been particularly shown and described herein above. Rather, the scope of a system and/or method for bimodal air control in a kettle-style grill according to the solution is defined by the claims that follow.