Patent EP0073111A1 successfully refreshed from Google Patents.
EP0073111A1
Expired / Lapsed
EP
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Improvements in and relating to fire and explosion detection and suppression
Assignee: Kidde Graviner Ltd
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Filing: 1982-08-02
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Granted: —
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Expires: 2002-08-02
Abstract
Abstract The invention discriminates between the explosion of an ammunition round itself and the fire or explosion (e.g. a hydrocarbon fire) which may then take place in the object (e.g. a vehicle) struck by the round and initiates suppression of the latter fire or explosion only. The vehicle carries a radiation detector which measures the ratio of the intensities of the radiation at 3.4 and 4.4 microns. When an exploding ammunition round passes through the fuel tank entraining initially unburning hydrocarbon fuel with it, the detector measures a relatively low ratio because the unburning hydrocarbon fuel vapor between the burning round and the detector has a very intense absorption band at 3.4 microns. Fire suppression is thus initiated, so as to suppress the hydrocarbon fire which would very shortly follow. If the round does not strike the fuel tank, hydrocarbon fuel vapor is not present in the vicinity of the exploding ammunition round and the ratio measured by the detector is higher and explosion suppression is not initiated.
Inventors
- 👤 Robert Lindsay Farquhar
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 14:05
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
71 words
A fire and explosion detection system capable of detecting the presence of a flammable substance (D) before it commences to burn, comprising a radiation detection arrangement (10) responsive to radiation in at least one narrow wavelength band, characterised in that the band is an absorption wavelength band characteristic of the said substance (D) and in that the arrangement (10) detects absorption of radiation in this band and produces an output accordingly.
Claim 2
Dependent Claim
71 words
A fire and explosion detection system capable of detecting the presence of a flammable substance (D) before it commences to burn, comprising a radiation detection arrangement (10) responsive to radiation in at least one narrow wavelength band, characterised in that the band is an absorption wavelength band characteristic of the said substance (D) and in that the arrangement (10) detects absorption of radiation in this band and produces an output accordingly.
Claim 3
Dependent Claim
40 words
A system according to claim 1, characterised in that the detection arrangement (10) comprises a detector (10A) operative to view a source of radiation (B) through a region (6) in which the flammable substance (D) is expected to be present.
Claim 4
Dependent Claim
28 words
A.system according to claim 2, characterised in that the source of radiation (B) is a fire or explosion of a different substance, such as a burning ammunition round.
Claim 5
Dependent Claim
32 words
A system according to claim 3, characterised by a fire and explosion suppression device (12) responsive to the output of the detection arrangement (10) so as to initiate fire or explosion suppression.
Claim 6
Dependent Claim
23 words
A system according to claim 4, characterised in that the flammable substance (D) is entrained unburning hydrocarbon fuel adjacent to the ammunition round.
Claim 7
Dependent Claim
77 words
A system according to claim 2, characterised in that the detection arrangement comprises a radiation detector (10A) arranged to produce an electrical signal in response to radiation received in a narrow wavelength band in which the said flammable substance (D) absorbs radiation from the said source, and by an output device (22) operative to sense the signal from the radiation detector (10A) to determine whether or not it is reduced by the presence of the flammable substance.
Claim 8
Dependent Claim
101 words
A system according to claim 6, characterised in that the detection arrangement (10) includes a second radiation detector (lOB) arranged to produce an electrical signal in response to radiation in a narrow wavelength band not associated with absorption by the flammable substance, and in that the said output device comprises a comparator (22) for comparing the signals of the two detectors (10A, 10B) whereby to produce the said output indicating the presence of a flammable substance (D) when the comparison indicates that the signal from the first-mentioned detector (10A) is relatively low compared with the signal from the second detector (lOB).
Claim 9
Dependent Claim
34 words
A system according to claim 8, characterised in that the narrow wavelength band to which the second detector (10B) is responsive is a narrow wavelength band of a combustion product of the flammable substance.
Claim 10
Dependent Claim
42 words
A system according to claim 7 or 8, characterised by a device (26) responsive to the signal produced by at least one of the detectors (10A, 10B) to block the said output if the signal level is less than a predetermined threshold.
Claim 11
Dependent Claim
46 words
A system according to claim 7, 8 or 9, characterised by a device (30) responsive to the signal produced by at least one of the two detectors (10A, 10B) to block the said output unless the signal level is rising at at least a predetermined rate.
Claim 12
Independent Claim
202 words
A system for protecting a target (16) carrying hydrocarbon fuel (D) against hydrocarbon fires caused by attack by an exploding ammunition round (B) but not against the exploding ammunition round itself, comprising a radiation detection arrangement (10) mounted on the target (6) so as to be capable of viewing an exploding ammunition round (B) after it has struck the target, and characterised in that the detection arrangement (10) includes a radiation detector (10A) arranged to be responsive to radiation in a narrow wavelength band centred at an intense absorption band characteristic of hydrocarbons so as to be capable of distinguishing between the relatively low radiation intensity in that band when the radiation from the exploding ammunition round (B) is sensed through hydrocarbon vapour (D) before the latter commences to burn and the relatively higher intensity in that band when the radiation from the exploding ammunition round (B) is sensed in the absence of such a vapour, and by an output device (22) responsive to the signal from the radiation detector (10A) and capable of producing warning output in the former condition but not the latter, and a device (12) responsive to the warning output to discharge a hydrocarbon fire suppressant or extinguishant.-
Claim 13
Independent Claim
202 words
A system for protecting a target (16) carrying hydrocarbon fuel (D) against hydrocarbon fires caused by attack by an exploding ammunition round (B) but not against the exploding ammunition round itself, comprising a radiation detection arrangement (10) mounted on the target (6) so as to be capable of viewing an exploding ammunition round (B) after it has struck the target, and characterised in that the detection arrangement (10) includes a radiation detector (10A) arranged to be responsive to radiation in a narrow wavelength band centred at an intense absorption band characteristic of hydrocarbons so as to be capable of distinguishing between the relatively low radiation intensity in that band when the radiation from the exploding ammunition round (B) is sensed through hydrocarbon vapour (D) before the latter commences to burn and the relatively higher intensity in that band when the radiation from the exploding ammunition round (B) is sensed in the absence of such a vapour, and by an output device (22) responsive to the signal from the radiation detector (10A) and capable of producing warning output in the former condition but not the latter, and a device (12) responsive to the warning output to discharge a hydrocarbon fire suppressant or extinguishant.-
Claim 14
Dependent Claim
90 words
A system according to claim 11, characterisedin that the detection arrangement (10) includes a second radiation detector (10B) responsive to the intensity of radiation in a narrow wavelength band characteristic of burning hydrocarbons and in that the output device (22) comprises a comparator (22) operative to measure the ratio between the signals produced by the two radiation detectors (10A, 10B) whereby to produce a said warning output, so that said warning output is produced in the presence of burning hydrocarbons whether or not an exploding ammunition round is also present.
Claim 15
Dependent Claim
55 words
A system according to claim 12, characterised by a device (26 and/or 30) responsive to the signal produced by at least one of the detectors (10A, 10B) to block the said output if the signal level is less than a predetermined threshold and/or unless the signal level is rising at at least a predetermined rate.
Claim 16
Independent Claim
85 words
A system according to any one of claims 6 to 13, characterised by a further detector (10C) responsive to radiation in a narrow wavelength band spaced from that of the first-mentioned detector (10A) such that a comparison of the signals from these detectors (10A, 10C) is a measure of apparent colour temperature, and by a device (24) for comparing the signals from these detectors (10A, 10B) to produce an inhibit signal for blocking the said output when the apparent colour temperature exceeds a predetermined value.
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