A high turn-down burner adapted to receive a fuel flow for combustion including an outer housing including a central axis, a side wall having a top edge and a bottom edge, a plurality of apertures disposed on the side wall, a top wall adjoining the side wall at the top edge and a bottom wall adjoining the side wall at the bottom edge; an inner housing including a central axis, a side wall, a plurality of apertures disposed on the side wall, the inner housing is coaxially rotatable with respect to the outer housing; and an actuator adapted to harness and convert the power exerted by the fuel flow to a movement of the inner housing with respect to the outer housing, wherein the alignment of the apertures of the inner and outer housings is adapted to modify an effective combustion area of the burner.

A high turn-down burner adapted to receive a fuel flow for combustion including an outer housing including a central axis, a side wall having a top edge and a bottom edge, a plurality of apertures disposed on the side wall, a top wall adjoining the side wall at the top edge and a bottom wall adjoining the side wall at the bottom edge; an inner housing including a central axis, a side wall, a plurality of apertures disposed on the side wall, the inner housing is coaxially rotatable with respect to the outer housing; and an actuator adapted to harness and convert the power exerted by the fuel flow to a movement of the inner housing with respect to the outer housing, wherein the alignment of the apertures of the inner and outer housings is adapted to modify an effective combustion area of the burner.

A method for the failsafe and lean ignition of a fuel gas-air mixture on a gas burner (6), which is mixed in a mixing device (4) arranged upstream of the gas burner (6). A control valve (2) along the fuel gas flow path has an actuator (21) and a throttle element (23), moved by the actuator (21), for the closed-loop control of a flow rate of the fuel gas flowing into the mixing device (4). A test is performed to determine whether the throttle element (23) is in the throttle reference position when the actuator (21) is in the actuator reference position. The throttle element (23) is moved in a flow rate-increasing manner starting at a start time (tD). The flow rate-increasing movement of the throttle element (23) is stopped as soon as at least one of multiple predetermined termination conditions occurs.

A burner box assembly according to aspects of the disclosure includes an outer cover, the outer cover having a sloped bottom face that directs condensation away from a heat-exchange tube, a heat-resistant liner having a plurality of panel members, the heat-resistant liner being disposed within the outer cover, a shield disposed between the heat-resistant liner and the sloped bottom face of the outer cover such that an air gap is formed between the shield and the sloped bottom face, and a tubular member abutting at least one of the plurality of panel members and disposed within the heat-exchange tube.

A burner box assembly according to aspects of the disclosure includes an outer cover, the outer cover having a sloped bottom face that directs condensation away from a heat-exchange tube, a heat-resistant liner having a plurality of panel members, the heat-resistant liner being disposed within the outer cover, a shield disposed between the heat-resistant liner and the sloped bottom face of the outer cover such that an air gap is formed between the shield and the sloped bottom face, and a tubular member abutting at least one of the plurality of panel members and disposed within the heat-exchange tube.

A flow control device for an appliance including a burner and a blower for delivering a pre-mixed mixture of air and gas to the burner includes a flange defining an opening through which the pre-mixed mixture of air and gas flows from an outlet of the blower to the burner. A damper plate is provided in the opening downstream of the blower for increasing a static pressure at the outlet of the blower during ignition of the burner.

A flow control device for an appliance including a burner and a blower for delivering a pre-mixed mixture of air and gas to the burner includes a flange defining an opening through which the pre-mixed mixture of air and gas flows from an outlet of the blower to the burner. A damper plate is provided in the opening downstream of the blower for increasing a static pressure at the outlet of the blower during ignition of the burner.

A device for controlling a fuel-oxidizer mixture for a premix gas burner, comprises: an intake duct for admitting the mixture into the burner; an injection duct, connected to the intake duct to supply the fuel; a monitoring device for checking the state of combustion in the burner; a gas regulating valve; a fan located in the intake duct; a control unit for controlling the speed of rotation of the fan between a first and a second rotation speed, corresponding to a minimum flow rate of oxidizer (Qmin) and a maximum flow rate of oxidizer (Qmax), respectively; a regulator coupled to the intake duct and having a first aperture, adjustable through a first shutter, and a second aperture, adjustable through a second shutter. The control unit is configured to drive the gas regulating valve in real time.

A double swirl burner including an annular air nozzle, an annular fuel nozzle coaxially disposed within the annular air nozzle, and a central air nozzle coaxially disposed within the annular fuel nozzle. An annular air nozzle may include at least one first inlet port on a peripheral wall of the annular air nozzle, where the first inlet port may be configured to allow for tangentially injecting a first air stream into the annular air nozzle. A first air stream may be tangent to a circular cross-section of the exemplary annular air nozzle, and a first axial inlet that may be configured to allow for axially injecting a second air stream into the annular air nozzle along a centerline of the annular air nozzle.

A double swirl burner including an annular air nozzle, an annular fuel nozzle coaxially disposed within the annular air nozzle, and a central air nozzle coaxially disposed within the annular fuel nozzle. An annular air nozzle may include at least one first inlet port on a peripheral wall of the annular air nozzle, where the first inlet port may be configured to allow for tangentially injecting a first air stream into the annular air nozzle. A first air stream may be tangent to a circular cross-section of the exemplary annular air nozzle, and a first axial inlet that may be configured to allow for axially injecting a second air stream into the annular air nozzle along a centerline of the annular air nozzle.