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US 10,345,152 B2Granted
Flame detectors and associated methods
AssigneeFFE Limited
InventorDaniel Waldron
Life of this patent
Estimating the term…
Abstract
A flame detector (1) including: a fire sensor (2a), capable of detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material; and a guard sensor (2b), for detecting an at least further part of the spectrum emitted by the material and which serves to assist in rejecting false alarms, wherein, in use during detection of a flame, the guard sensor (2b) detects an amount of radiation G and the fire sensor (2a) detects an amount of radiation F, and positive detection of a flaming material depends upon the following criteria: F>0; G>0; and F>G.
Claims21
A flame detector comprising:
- a fire sensor, capable of detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material, the fire sensor being configured to detect an intensity of radiation F in a fire band range of wavelengths of from 1.6 μm to 2.4 μm;
- and
- a guard sensor, for detecting an at least further part of a spectrum emitted by said material and which serves to assist in rejecting false alarms, the guard sensor being configured to detect an intensity of radiation G in a guard band range of wavelengths, and the guard sensor being configured to detect radiation of shorter wavelength than the fire sensor, and
- wherein the guard band and fire band are infrared detection bands, the guard band range of wavelengths is narrower than the fire band range of wavelengths, and each band range of wavelengths is distinct and separated from the other by a sensory gap of 0.5 μm to 1 μm, wherein neither the fire sensor nor the guard sensor are configured to detect in a wavelength region of the spectrum above 3.2 μm, and
- the flame detector is configured to positively detect flaming material when (i) the fire sensor detects that the intensity of radiation F is greater than zero, (ii) the guard sensor detects that the intensity of radiation G is greater than zero, and (iii) the flame detector determines that the intensity of radiation F detected by the fire sensor is greater than the intensity of radiation G detected by the guard sensor.
2 more elements
A method for flame detection comprising:
- using a fire sensor to detect an intensity of radiation F in a fire band range of wavelengths of from 1.6 μm to 2.4 μm from a characteristic blackbody-type radiated heat signature emitted by a flaming material, and without detecting an electromagnetic spectrum in a region above 3.2 μm;
- and
- using a guard sensor to detect an intensity of radiation G in a guard band range of wavelengths from an at least further part of the electromagnetic spectrum emitted by said material which serves in assisting rejection of false alarms, and without detecting the electromagnetic spectrum in the region above 3.2 μm,
- wherein, the wavelengths detected in the guard band range are shorter than the wavelengths detected in the fire band range, wherein the guard band and fire band are infrared detection bands, and the guard band range of wavelengths is narrower than the fire band range of wavelengths and each band range of wavelengths is distinct and separated by a sensory gap of 0.5 μm to 1 μm from the other, and
- detecting a flame if (i) the intensity of radiation F is greater than zero, (ii) the intensity of radiation G is greater than zero, and (iii) the detected intensity of radiation F is greater than the detected intensity of radiation G.
2 more elements
A flame detector comprising:
- a first sensor for detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material, being configured to detect radiation having only a wavelength range of 1.6 μm to 2.4 μm;
- and
- a second sensor for detecting an at least further part of a spectrum emitted by said material and which serves to assist in rejecting false alarms, the second sensor being configured to detect radiation having a wavelength range of 0.6 μm to 1.4 μm, each sensor comprises lead sulphide (PbS) or indium gallium arsenide (InGaAs);
- wherein neither the first sensor nor the second sensor are configured to detect in a wavelength region of the spectrum above 3.2 μm.
1 more element
Dependencies are inferred from the claim text.