A flame sensing system, a flame sensing unit, and a method for sensing a flame are described. The flame sensing system includes a flame sense probe and a power regulating device. The power regulating device is configured to generate a regulated voltage from an input voltage received from a power source and to output the regulated voltage to the flame sense probe such that a flame current along a flame can be measured. The flame sensing system also includes a flame current detector to measure the flame current and generate an output voltage corresponding to the flame current, and a first level detector to generate a flame strength output signal based on the output voltage, where the flame strength output signal is indicative of a strength of a flame.

Various embodiments include a control system comprising: an ionization electrode; a flame sensor; a first signal conditioning circuit for the ionization electrode; a second signal conditioning circuit for the flame sensor; an output unit; and a processor. The processor: receives a first and a second ionization signal indicative of ionization currents from the first signal conditioning circuit; receives a first and a second flame signal indicative of radiations originating from a flame via the second signal conditioning circuit; produces a derived ionization signal as a function of the first and the second ionization signals; produces a derived flame signal as a function of the first and the second flame signals; determines if a flame lift-off condition exists based on the derived ionization signal and the derived flame signal; and if a flame lift-off condition exists, produces a safety signal and transmits the safety signal to the output unit.

Methods and apparatus to indicate presence of a flame are disclosed. An example gas grill includes a burner tube having apertures to emit a fuel for combustion, an ignition element to cause ignition of the fuel emitted from the apertures of the burner tube, a flame sensor to detect the presence of a flame associated with the combustion of the fuel emitted from the apertures of the burner tube, and flame sense circuitry including a flame signal accessor to access a flame sense signal from the flame sensor, and a terminal to output an indication of the presence of the flame, the indication of the presence of the flame output without respect to an open or closed state of a lid of the grill.

A method for operating a combustion chamber is provided. The method includes obtaining a carbon monoxide reading at an exit of the combustion chamber via a carbon monoxide sensor, and deriving an oxygen set point trim based at least in part on the carbon monoxide reading and a carbon monoxide set point via a controller. The method further includes determining a stability status of the combustion chamber via a combustion stability sensor, and adjusting an oxygen set point of the combustion chamber with the oxygen set point trim based at least in part on the stability status via the controller. The oxygen set point defines a desired oxygen level at the exit of the combustion chamber.

Various embodiments include a control system comprising: an ionization electrode; a flame sensor; a first signal conditioning circuit for the ionization electrode; a second signal conditioning circuit for the flame sensor; an output unit; and a processor. The processor: receives a first and a second ionization signal indicative of ionization currents from the first signal conditioning circuit; receives a first and a second flame signal indicative of radiations originating from a flame via the second signal conditioning circuit; produces a derived ionization signal as a function of the first and the second ionization signals; produces a derived flame signal as a function of the first and the second flame signals; determines if a flame lift-off condition exists based on the derived ionization signal and the derived flame signal; and if a flame lift-off condition exists, produces a safety signal and transmits the safety signal to the output unit.

An apparatus may comprise a first carrier tube having a first input end and a first output end and a second carrier tube disposed substantially parallel to the first carrier tube and having a second input end and a second output end. A cross tube may be coupled to the first carrier tube and the second carrier tube and may be disposed substantially perpendicularly between the carrier tubes. A plurality of burner holes may be disposed along the first carrier tube, the second carrier tube, and the cross tube. A plurality of flame sensors may be disposed at various locations of the first carrier tube and the second carrier tube. A first igniter assembly may further be coupled to the first carrier tube.

An intelligent cooktop has at least a first, if not multiple burners in proximity to at least a first sensor, respectively, wherein the first sensor provides an input to a processor which evaluates a burner performance characteristic selected from the group of least one of flame level, temperature rise, time lag, and temperature level using the first sensor compared to an anticipated performance characteristic of the first burner based on the valve position; and then provides a burner performance output to a user identifying a condition of the first burner.

A method for operating a combustion chamber is provided. The method includes obtaining a carbon monoxide reading at an exit of the combustion chamber via a carbon monoxide sensor, and deriving an oxygen set point trim based at least in part on the carbon monoxide reading and a carbon monoxide set point via a controller. The method further includes determining a stability status of the combustion chamber via a combustion stability sensor, and adjusting an oxygen set point of the combustion chamber with the oxygen set point trim based at least in part on the stability status via the controller. The oxygen set point defines a desired oxygen level at the exit of the combustion chamber.

A modular flame amplifier system having a base module, a burner control and one or more flame amplifier modules connected to the burner control. One or more sensors may be connected to the one or more flame amplifier modules. Some of the flame amplifiers may be a long distance from the burner control module. Some of the flame amplifiers may be connected to the burner control via a cable. The connection between some of the flame amplifiers and the respective sensors may be less noise tolerant than the long cable connection between the one or more flame amplifiers and the burner control. One or more flame amplifiers may be mounted on the same rail as the burner control or another rail remote from the burner control. Two or more sensors may be connected in one or more of several configurations along with delay in some configurations.

Provided are a method and an arrangement for monitoring performance of a burner of a suspension smelting furnace. The burner is arranged at the top structure of a reaction shaft of the suspension smelting furnace. The burner has a solids feeding channel that has a solids outlet opening up into the reaction shaft, and a reaction gas channel comprising a reaction gas channel a that has a reaction gas outlet opening up into the reaction shaft. The arrangement comprises at least one imaging means for producing images representing the cross-section of the reaction gas channel, and a processing means for receiving images of the cross-section of the reaction gas channel from the imaging means.