Burner flame sensing system and method
First Claim
1. A flame analyzer comprising:
- a sensor for detecting radiation produced by a flame and producing an electrical signal indicative of the radiation;
means for converting the electrical signal into a spectrum comprising a plurality of component frequencies of the electrical signal, the component frequencies resulting from changes in power of the flame with time, and wherein each component frequency has an amplitude;
means for determining a degree of linearity of a distribution of component frequency amplitudes throughout the spectrum; and
means for determining a characteristic of the flame in response to the degree of linearity.
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Accused Products
Abstract
The presence of a flame from a burner is determined by analyzing the signal produced by a radiation sensor aimed at a burner. Specifically, a Fourier transformation is applied to the signal producing amplitude values for a spectrum of component frequencies produced by changes in the power of the flame over time. A logarithmic value is derived for each of the amplitude values. The degree of linearity of the distribution of the component frequency logarithmic amplitude values provides an indication of the flame presence. Several parameters, including integrated linear error, linearity regression correlation and slope difference, provide an indication of the degree of linearity. A plurality of values for each of these parameters are produced during an interval of time. When a given percentage of the parameter values are above their respective thresholds the flame is determined to be present, whereas when another given percentage of the parameter values are below their respective threshold the flame is determined to be extinguished.
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Citations
21 Claims
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1. A flame analyzer comprising:
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a sensor for detecting radiation produced by a flame and producing an electrical signal indicative of the radiation; means for converting the electrical signal into a spectrum comprising a plurality of component frequencies of the electrical signal, the component frequencies resulting from changes in power of the flame with time, and wherein each component frequency has an amplitude; means for determining a degree of linearity of a distribution of component frequency amplitudes throughout the spectrum; and means for determining a characteristic of the flame in response to the degree of linearity. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus for detecting the presence of a flame comprising:
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a sensor for detecting radiation produced by a flame and producing an electrical signal indicative of the radiation; an automatic gain controlled amplifier for amplifying the electrical signal; means for digitizing the electrical signal from said amplifier into a plurality of signal samples; means for storing the plurality of signal samples; means for transforming the signal samples from a time domain to a frequency domain to produce a plurality of component frequency amplitude values; means for deriving a logarithmic value for each component frequency amplitude value of the electrical signal; means for determining a degree of linearity of a distribution of the logarithmic values; and means for evaluating the degree of linearity to determine whether the flame is present. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A method for determining a characteristic of a flame comprising:
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detecting radiation at a frequency produced by a flame and producing an electrical signal indicative of the radiation; transforming the electrical signal from a time domain to a frequency domain to produce amplitude values for a plurality of component frequencies which result from shape changes of the flame with time; determining a degree of linearity of a distribution of the amplitude values; and employing the degree of linearity to determine a flame characteristic. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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Specification