Dual mode downdraft gas range

A dual mode gas range, comprising:

• an open top burner box, formed by a bottom, two sides and two faces, a range top connected to the open top of the burner box, and a plurality of gas burners sealed to the range top to provide a sealed top gas range assembly forming an enclosed but unsealed space between the range top and burner box;
• a combined air/gas supply to supply gas and primary combustion air to said plurality of gas burners through a plurality of sealed conduits,
• said combined air/gas supply comprising an air plenum formed by one side of said burner box and a blower having its inlet in communication with an opening formed in the bottom of said burner box and its outlet in communication with said air plenum,
• said one side of said burner box that forms said air plenum including a circulating air opening communicating with said enclosed but unsealed space formed by the range top and the bottom, sides and faces of said burner box,
• said air plenum and said enclosed but unsealed space comprising a path for circulating air flow generated by said blower;
• a plurality of other air flow paths for primary combustion air from said blower,
• each of said plurality of other air flow paths including said air plenum, said sealed conduits and said gas burners;
• and
• an adjustable shutter carried adjacent to said circulating air opening between said air plenum and said enclosed but unsealed space, said adjustable shutter providing adjustment of the air pressure within said air plenum that is available to direct primary combustion air flow through said plurality of other air flow paths.

A dual mode downdraft range comprising:

• an open top burner box formed by a bottom, two sides and two faces;
• a downdraft plenum extending through the bottom of said burner box, said downdraft plenum extending partially between said two faces;
• a downdraft exhaust blower;
• a range top connected to the open top of said burner box and providing a space between said burner box and range top;
• a plurality of gas burners sealed to the range top, said range top, burner box and downdraft plenum providing a sealed top gas range assembly, said range top providing an exhaust opening into said downdraft plenum and an atmospheric air opening into the space between said burner box and range top;
• an air/gas supply for supplying gas and primary combustion air to the plurality of gas burners through a plurality of air/gas chambers connected with a plurality of sealed conduits;
• said air/gas supply further comprising a combustion air blower having its inlet in communication with an opening formed in the bottom of said burner box and its outlet in communication with an air plenum located at and formed by one side of said burner box;
• said one side of said burner box forming said air plenum including a circulating air opening communicating with the space formed between said range top and said burner box and further including a plurality of gated openings, each of said gated openings communicating with said space between said burner box and range top and one of said air/gas chambers;
• an air gate operable to open and close said gated openings;
• a control for operating said range in a power burner mode by operating said combustion air blower, said downdraft exhaust blower and said air gate to close said gated openings,
• said air plenum and space comprising one path for air flow generated by said combustion air blower, and
• a plurality of other air flow paths for primary combustion air flow from said combustion air blower and said air plenum being formed by said plurality of chambers, sealed conduits and gas burners;
• and
• an adjustable shutter carried adjacent to said circulating air opening between said air plenum and said space between said burner box and range top, said adjustable shutter adjustably varying the size of said circulating air opening to adjust said air plenum pressure available to direct primary combustion air flow through said plurality of other air flow paths,
• said gated openings being open when said range is not in the power burner mode to provide a flow path for primary combustion air from atmosphere through said atmospheric air opening in said range top, said space between said burner box and range top, and said plurality of chambers, sealed conduits and gas burners.

A downdraft gas range adapted to provide a gas burner with a powered flow of primary combustion air, comprising:

• a cooktop comprising a top surface adapted to be connected to a sealed gas burner assembly;
• a downdraft plenum adjacent said sealed gas burner assembly for withdrawing combustion byproducts and cooking vapors from adjacent said top surface and sealed gas burner assembly;
• said sealed gas burner assembly comprising a gas burner having a plurality of burner outlets;
• a combined air and gas flow supply, including an air mover for providing air flow at pressures above atmospheric pressure in the presence of a downdraft exhaust, and a gas flow source;
• a sealed conduit connected between said sealed gas burner assembly and said combined air and gas flow supply for delivering a combined flow of primary combustion air and gas from said air mover and gas flow source;
• and
• a diffuser between said gas burner and said sealed conduit to diffuse the flow of gas and air.

A downdraft gas range with a sealed top, comprising:

• at least one sealed gas burner assembly carried by said sealed top and comprising a gas burner and a connected sealed conduit;
• a downdraft exhaust system adjacent said gas burner comprising a downdraft plenum connected with an exhaust blower;
• a combined air and gas supply controller connected with said sealed conduit, said combined air and gas supply controller comprising a chamber for housing an air-gas mixer, said chamber being connectable through a gas flow control valve with a source of gas under pressure and through an air flow control valve with a combustion air blower and having a gated opening communicating with atmosphere;
• and
• a control for operation of said gas range, said gas range control including electrical switches to operate said combustion air and exhaust blowers and to close said gated opening of the combined air and gas supply controller for operation in a powered burner mode and to prevent operation of said combustion air and exhaust blowers and open said gated opening of the combined air and gas supply controller in an atmospheric burner mode.

A method of dual mode cooking with a sealed gas burner, comprising:

• providing a controlled flow of cooking gas to an injection chamber for mixing with a flow of primary combustion air and for direction through a sealed conduit to a plurality of outlets of the sealed burner;
• providing a powered mode of operation of the sealed burner by providing a controlled, forced flow of primary combustion air to the injection chamber from a combustion air blower through an air flow control valve located between the combustion air blower and the injection chamber for mixing with the controlled flow of cooking gas and direction to the outlets of the sealed burner through the sealed conduit;
• and
• providing an atmospheric mode of operation of the sealed burner by opening the injection chamber to atmosphere and allowing a substantially unobstructed flow of air to enter the injection chamber for mixing with the cooking gas and direction to the outlets of the sealed burner through the sealed conduit.