US3504184A - Radiation sensitive smoke detector using light conducting means - Google Patents

Radiation sensitive smoke detector using light conducting means Download PDF

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Publication number
US3504184A
US3504184A US690320A US3504184DA US3504184A US 3504184 A US3504184 A US 3504184A US 690320 A US690320 A US 690320A US 3504184D A US3504184D A US 3504184DA US 3504184 A US3504184 A US 3504184A
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United States
Prior art keywords
light
smoke
path
air
rod
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US690320A
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English (en)
Inventor
Colin Ashton Eaton
William Walter Cozens
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Kidde Inc
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Walter Kidde and Co Inc
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Publication date
Application filed by Walter Kidde and Co Inc filed Critical Walter Kidde and Co Inc
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Publication of US3504184A publication Critical patent/US3504184A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device
    • G08B17/107—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device for detecting light-scattering due to smoke
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G08B17/113—Constructional details

Definitions

  • Smoke detection apparatus including a visual smoke detector comprising a dark chamber providing an air path, a light-carrying rod, such as a glass fibre light guide, for Conveying light from a light source and for causing this to pass along a light path through the air path, and a window through which the light path may be viewed.
  • a visual smoke detector comprising a dark chamber providing an air path, a light-carrying rod, such as a glass fibre light guide, for Conveying light from a light source and for causing this to pass along a light path through the air path, and a window through which the light path may be viewed.
  • a second light-carrying rod may be provided spaced by a small gap from the end of the first-mentioned rod, the said gap constituting the light path.
  • This second rod preferably carries the light received from the first rod to provide a source of illumination for a second smoke detector.
  • This second smoke detector preferably incorporates a light sensitive electric cell.
  • the second smoke detector may conveniently comprise two light paths lying between and extending respectively from the said light source and the said electric cell and being mutually inclined so that the said electric cell is masked from the light source, the arrangement being such that when smoke particles are present at the intersection between the two light paths, these smoke particles cause light from the light source to be deflected on to the light sensitive electric cell.
  • the said light paths are inclined to each other by an obtuse angle, preferably 120 or greater and in a preferred embodiment 150.
  • the light paths are formed in a block so arranged that the intersection of the light paths take place at a location spaced from the block, the block preferably having a flat surface located between the light paths.
  • the smoke detection apparatus preferably comprises a single housing for both detectors.
  • the apparatus comprises a plurality of units, there being a single source of light to which the remote ends of the said first rods are exposed.
  • FIGURE 1 is a perspective view of a system comprising two banks of units of the invention
  • FIGURE 2 is a side view of the system of FIGURE 1 with side walls of the apparatus housing removed,
  • FIGURE 3 shows the light source for one bank
  • FIGURE 4 is the front view of smoke detection unit of the invention.
  • FIGURE 5 is a section on line 5-5 of FIGURE 4,
  • FIGURE 6 is a section on line 66 of FIGURE 5, and
  • FIGURE 7 is a circuit diagram showing the main circuit and the circuit for one unit.
  • Each light ice source 11 comprises a quartz iodine axial filament lamp 12.
  • the lamp 12 is located in a light-proof housing 13 (see FIGURE 3) having a hinged door 14 (see FIGURE 2) for removal of the lamp 12.
  • a plurality of rods 15, one for each unit 10 in a bank have their ends (hereinafter called their remote ends) opening into the housing 13.
  • These rods 15 may be made of glass or Perspex (registered trademark) or may preferably be fibre optical rods.
  • the other (or inner end) of each rod 15 is connected to a union 16 secured into the upper wall of the housing of a smoke detection unit 11.
  • the housing 17 of each detector unit comprises front, rear, top and bottom walls 17a, 17b, 17c and 17d respectively.
  • Two intermediate walls 17e and 17 are also provided parallel to the top and bottom walls.
  • the front wall 17a is the widest wall, the intermediate walls 172 and 17] being slightly less wide but wider than the remaining walls.
  • the intermediate walls 17e and 17 slot into recesses in the side walls of the cabinet 18 to form an air and lighttight seal therewith.
  • the rear wall 17!; of the housing 17 has an air inlet socket 19 and above it an air outlet socket 21.
  • the inlet socket 19 is connected by means of a flexible pipe 22 (not shown) to a hold of the ship.
  • the outlet socket 21 is connect'ed by a conduit 22 to a header chamber 23 common to each bank.
  • a suction pump 20 applies suction pressure to each header chamber 23.
  • the outlet from the pump 20 is connected by a three-way valve either to a sniffer pipe which opens in the ships wheel house or to an exhaust pipe.
  • each unit has a matt black non-reflective finish.
  • the housing 17 which is preferably a fabricated steel housing, although it could be a plastics casting, defines an air path connecting the two sockets 19 and 21.
  • the air path comprises a lower horizontal path 27 between walls 17d and 17 1 leading from the inlet connection 19; an upper mainly horizontal path 28 between walls and 17e leading to the outlet connection 21; and vertical connecting path 29 leading from a square aperture 30 in the wall 17 to upper horizontal path 28.
  • a tubular sighting duct 31 opens into the upper path 28 and is closed off by an angled glass window 32.
  • the union 16 is, as described above, secured to the top wall 170 of the housing 17 and is located close to the outlet connection 21.
  • a second rod 33 which is similar to rod 16, has an end aligned with the inner end of the rod 15 in the intermediate wall 17e. Short lengths of tubing 34 are provided on and extending slightly beyond the projecting ends of the rods 16 and 33 so that these ends are not visible through the sighting duct 31. The gap between the ends of the rods 15 and 33 provides a first smoke detector as will be described in detail below.
  • An air-flow indicator in the form of three flexible nylon wands 36, which are white or any other bright colour, is located close to the air outlet 21. When air passes along the air path, the nylon wands 36 are deflected from their vertical position and wave in the air flow.
  • the second rod 33 leads to a second smoke detector 37.
  • This smoke detector 37 comprises a block 38 in which are formed two light passages 39 and 40.
  • the light passages 39 and 40 open in a projection 41 of the block 38 which is located in an aperture in wall 17a.
  • These light passages 39 and 40 are inclined to the wall 17f by a small angle of about 15.
  • the continuation of the light passages 39 and 40 meet a short distance before the front face of the block leaving a small flat plateau 42 between the light passages 39 and 40. This plateau 42 prevents dust lodging at the intersection of the light passages.
  • the second rod 33 terminates short of the surface 38.
  • At the outer end of the light passage 41 there is provided a cadmium disulphide, photo resistive light sensitive cell 43.
  • the unit circuit Cr of the cell 43 is shown in FIGURE 5.
  • the cell LC is connected to the variable outlet of a 1 megohm potentiometer P and through an 0.1 megohm resistor Res to the base of one transistor T of a Darlington pair.
  • the common collector is con nected to a relay R
  • This relay R controls a relayswitch RS connected in across the supply in series with the zone indicator light 46.
  • the relay switch R8 is also connected to the main alarm system through a diode D.
  • the unit circuit is fed from a common stabilised power supply circuit.
  • Mains power is fed to the primary of an input transformer having a 24 v. and a 40 v. secondary winding SW and SW
  • One winding SW has two lamps 12 connected thereacross.
  • a relay R is connected in parallel with the lamps 12.
  • a pair of relay switches R 8 and R 8 are provided across the lamp pair. These switches normally, i.e. when the relay R is energised, connect the lamps 12 to the winding SW
  • the other winding SW is connected to a rectifier bridge B.
  • a smoothing capacitor C extends across the bridge output.
  • Connected to the negative line is a Zener diode Z connected via a K ohm resistor R to the positive line.
  • the junction of the Zener diode Z and resistor R is connected to the base of the transistor T and to a capacitor C leading to the negative line.
  • the transistor collector leads to the positive line and the emitter is connected to the positive line and through a capacitor C to the negative line.
  • In the negative and positive lines are two relay switches R 8 and R 8 respectively. When the relay R is energised these switches connect these lines to the bridge B.
  • the relay switches R 5 R 8 R 8 and R 5 are two position switches. When the relay is de-energiscd, as on mains power failure, these switches connect the lamps and the power lines of the supply circuit in parallel to a standby battery unit By.
  • a shut-01f butterfly valve 49 is provided to seal off the aperture 30 thereby preventing flow through the vertical path 29.
  • a handle 51 is located on the front face 52 of front wall 171: for controlling the position of the valve 49.
  • This valve 49 is provided to isolate a hold containing a substance, such as cement, which will not burn but which gives oif dust that will be sucked through the apparatus causing the alarm to be given and the apparatus to be dirtied.
  • the valve 49 is movable by the handle 51 from a fully open to a fully closed or sealed position.
  • the valve 49 may also be adjusted to lie in the continuation of the light path 39 to reflect light into the light path 41 so as to test the operation of the apparatus.
  • a conventional fault circuit is connected to the lamp 12 to give a fault signal should this lamp fail.
  • the units connected to holds containing nonburning and dusty substances are shut off by their'valves .4 49, the three-way valve connects the pump outlet to the sniffer pipe, the common lamps 12 are illuminated, and the suction pump 20 is operating.
  • the nylon wand air-flow indicator 36 will wave in the air flow so that a viewer can check that air is passing through the air path in each housing. While there is no smoke to be detected, the cells 43 will remain in darkness and the circuits will give no signals.
  • the electric and the visual indications of smoke will be given by the apparatus at very low smoke concentra tions.
  • the first or visual detector will give an indication of smoke at as low a concentration as two percent obscuration per foot Whilst the electric or second detector is even more sensitive. Thus remedial fire fighting action can be taken at a very early stage.
  • the first or visual detector provided by the gap between the rods 15 and 33 also serves to actuate the second or electric detector at low smoke concentrations as will now be described.
  • the light leaving the inner end of the rod 16 disperses in the shape of a cone. Of this cone of light only the central cylindrical part falls on the end of the rod 33. The remaining part of the cone of light, which part is herein defined as the cone annulus, does not fall on the end of the rod 33.
  • these particles when there is a low concentration of smoke particles in the air drawn into the air path, these particles, when in the cone annulus, will reflect light on to the end of the rod 33.
  • more light will pass from the light passage 39 and the scatter light falling on the cell 43 will likewise increase. This in turn will reduce the resistance of the cell 43, causing the Darlington pair to fire so that the alarm signal will be given in the unlikely event it has not already been given.
  • the block 38 may be recessed at the commencement of the light path.
  • scatter light leaving the end of the rod 33 will be absorbed in the recess to a substantial extent and will not be reflected down the path 39.
  • low ridges may be provided to mask the ends of rods 15 and 33.
  • a flashing zenon light, flashing every five seconds, may replace the quartz iodine lamp.
  • the apparatus can also be used in a building where a number of rooms or zones are being policed by the fire detection apparatus.
  • a dark chamber provided with a viewing window
  • a light source being provided to illuminate any smoke particles in said stream of air to render the same visible
  • a light sensitive cell screened from said light source, being arranged in said chamber to be illuminated by reflected light from smoke particles in said stream of air characterised in that the stream of air is moved past one end of a light-carrying rod (15, 33) and through a gap in said rod to provide two separate positions at which smoke particles in said air stream are illuminated from a com mon light source.

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Management (AREA)
  • Business, Economics & Management (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
US690320A 1966-11-28 1967-12-13 Radiation sensitive smoke detector using light conducting means Expired - Lifetime US3504184A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB5322666 1966-11-28
GB39985/67A GB1179409A (en) 1966-11-28 1966-11-28 Improvements in or relating to Smoke Detectors
US69032067A 1967-12-13 1967-12-13

Publications (1)

Publication Number Publication Date
US3504184A true US3504184A (en) 1970-03-31

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US690320A Expired - Lifetime US3504184A (en) 1966-11-28 1967-12-13 Radiation sensitive smoke detector using light conducting means

Country Status (8)

Country Link
US (1) US3504184A (de)
BE (1) BE707196A (de)
DE (1) DE1673329A1 (de)
DK (1) DK122549B (de)
FR (1) FR1547849A (de)
GB (1) GB1179409A (de)
NL (1) NL6716159A (de)
SE (1) SE343969B (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3678511A (en) * 1969-12-09 1972-07-18 Elmer M Benedict Alarm circuit
US3805066A (en) * 1972-08-14 1974-04-16 T Chijuma Smoke detecting device utilizing optical fibers
JPS4946484A (de) * 1972-09-05 1974-05-04
US3870417A (en) * 1973-07-17 1975-03-11 Whirlpool Co Sensor for dishwasher
US3936814A (en) * 1974-04-29 1976-02-03 Bernz-O-Matic Corporation Smoke detector and alarm
JPS5166891A (ja) * 1974-12-06 1976-06-09 Nippon Steel Corp Renzokushikibiryoyunodosokuteisochi
CN112313720A (zh) * 2018-06-19 2021-02-02 瓦格纳集团责任有限公司 散射光检测器和具有散射光检测器的吸气式火灾检测系统
CN113168752A (zh) * 2018-10-15 2021-07-23 庞巴迪运输有限公司 用于分段探测烟雾的烟雾探测器和具有烟雾探测器的车辆
US11293865B2 (en) 2016-11-11 2022-04-05 Carrier Corporation High sensitivity fiber optic based detection

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2036476A5 (de) * 1969-03-13 1970-12-24 Guigues Frederic

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2256595A (en) * 1939-07-13 1941-09-23 Photoswitch Inc Photoelectric system
US2291776A (en) * 1941-01-16 1942-08-04 Wager Robert Hudson Combined smoke observation device and photoelectric indicating means
US2306588A (en) * 1940-01-23 1942-12-29 C O Two Fire Equipment Co Smoke detecting apparatus
US2410104A (en) * 1942-08-27 1946-10-29 Fed Telephone & Radio Corp Light directing device
US2892378A (en) * 1955-04-26 1959-06-30 Gen Electric Indicating turbidimeter
US3045223A (en) * 1959-07-08 1962-07-17 Chicago Aerial Ind Inc Device for detecting the presence of foreign material
US3168218A (en) * 1962-09-18 1965-02-02 Waukesha Foundry Co Metering device with opaqueness responsive shutoff

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2256595A (en) * 1939-07-13 1941-09-23 Photoswitch Inc Photoelectric system
US2306588A (en) * 1940-01-23 1942-12-29 C O Two Fire Equipment Co Smoke detecting apparatus
US2291776A (en) * 1941-01-16 1942-08-04 Wager Robert Hudson Combined smoke observation device and photoelectric indicating means
US2410104A (en) * 1942-08-27 1946-10-29 Fed Telephone & Radio Corp Light directing device
US2892378A (en) * 1955-04-26 1959-06-30 Gen Electric Indicating turbidimeter
US3045223A (en) * 1959-07-08 1962-07-17 Chicago Aerial Ind Inc Device for detecting the presence of foreign material
US3168218A (en) * 1962-09-18 1965-02-02 Waukesha Foundry Co Metering device with opaqueness responsive shutoff

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3678511A (en) * 1969-12-09 1972-07-18 Elmer M Benedict Alarm circuit
US3805066A (en) * 1972-08-14 1974-04-16 T Chijuma Smoke detecting device utilizing optical fibers
JPS4946484A (de) * 1972-09-05 1974-05-04
US3870417A (en) * 1973-07-17 1975-03-11 Whirlpool Co Sensor for dishwasher
US3936814A (en) * 1974-04-29 1976-02-03 Bernz-O-Matic Corporation Smoke detector and alarm
JPS5166891A (ja) * 1974-12-06 1976-06-09 Nippon Steel Corp Renzokushikibiryoyunodosokuteisochi
US11293865B2 (en) 2016-11-11 2022-04-05 Carrier Corporation High sensitivity fiber optic based detection
CN112313720A (zh) * 2018-06-19 2021-02-02 瓦格纳集团责任有限公司 散射光检测器和具有散射光检测器的吸气式火灾检测系统
CN113168752A (zh) * 2018-10-15 2021-07-23 庞巴迪运输有限公司 用于分段探测烟雾的烟雾探测器和具有烟雾探测器的车辆
CN113168752B (zh) * 2018-10-15 2023-09-22 庞巴迪运输有限公司 用于分段探测烟雾的烟雾探测器和具有烟雾探测器的车辆

Also Published As

Publication number Publication date
SE343969B (de) 1972-03-20
GB1179409A (en) 1970-01-28
FR1547849A (fr) 1968-11-29
NL6716159A (de) 1968-05-29
DK122549B (da) 1972-03-13
DE1673329A1 (de) 1972-03-02
BE707196A (de) 1968-04-01

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