Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL 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 SYSTEMS, e.g. PERSONAL 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

• the invention relates to a self-priming fire alarm device for monitoring technical systems, buildings and storage areas for the occurrence of fires according to the preamble of claim 1.
• Self-priming fire alarm systems are to be understood as fire alarm systems that have one or more suction pipes, the suction openings of which take air samples from the area of the system or room to be monitored and feed the fire detection detectors to measure different fire parameters.
• Fans or fans are often used as suction means for generating a continuous air flow from the monitoring area, but piston or diaphragm pumps are also used in various ways.
• Self-priming systems are used to advantage if only a low thermal develops during a smoldering fire and smoke particles only very slowly reach the detection area of the fire detectors, which are often located at greater distances.
• suction openings can be located within certain areas of the system at risk, such as the housing of an electrical control cabinet or an EDP system, so that the air samples are more specific directly from the hazardous area
• Plant objects can be removed and recorded together.
• Emerging fires in plant areas can be detected early and suitable countermeasures taken.
• Such known systems are available in numerous variants and mostly use an LED or a laser diode as a scattered light source.
• the light beams emitted by the light source pass through a measuring section through a sample volume and are scattered on existing smoke particles.
• the inhomogeneously distributed scattered light is then one or more
• Receiving elements in a measurable electrical
• the intensity of the scattering angle of the scattered light is u. a. depends on the
• Receiving elements can draw conclusions about the number and in the
• Laser measuring system operated with the air sample chamber and the gas supply.
• Deceptive variables can be expected.
• Representative partial quantities are taken from the ambient air or cooling air of a hazardous area to be monitored via two intake pipe systems and fed to a detector for recognizing a fire parameter.
• Detector chamber plays an important role.
• Scattered light principle includes smoke detector, the stray light receiver can be positioned at different scattering angles.
• the optical scattered light measuring system be additionally equipped with a
• Equip polarization filters and determine the degree of polarization of the scattered light.
• a definite type of smoke can then be concluded from the clear correlation between the degree of polarization and the scattering angle.
• Types of smoke with threshold values are stored in databases, which are then linked to the
• Results of the scattered light and polarization measurement can be compared.
• the fire alarm device according to the invention should be able to generate various alarm levels in accordance with the fire development, which permits the use of graduated flexible fire-fighting measures.
• the aim is to minimize the frequency of false alarms while increasing the
• Sensitivity of the system can be achieved.
• Both the optical stray light measuring system and the gas sensors connected to a microcontroller system and / or a fire alarm system.
• the invention also relates to a method for operating this fire detection device, which is characterized by the formation of a sum signal from the measured variables detected in different scattering angles of the optical scattered light measuring system and the measured variables detected by the additionally arranged gas sensors and / or the gas sensor array.
• the receiving elements of the scattered light measuring system are arranged in the forward and backward scattering directions and their signal processing is designed in such a way that parameters, such as particle color, size and concentration, are characteristic of the particles in a defined sample volume by the simultaneous detection of the forward and backscatter angle ranges of detected signals can be determined.
• the simultaneous detection and processing of the light beams scattered at different angles is particularly important with the measuring system receiver-microcontroller system.
• Scattered light signals from the different scattered light angles allow a precise description of the particle distribution in the sample volume at a certain point in time, since the sample volume is not a static variable, but rather its parameters depend on the
• fire detectors of various types such as temperature detectors or ionization smoke detectors
• Fire alarm device arranged and connected to the microcontroller system and / or the fire alarm control center.
• these detectors and also the gas sensors directly in the intake flow of the intake device their arrangement in a bypass to the intake pipe is also possible.
• the measurement quantities determined by the latter fire detectors in the sample volume are also included in the signal processing of the fire detection device and are weighted accordingly using evaluation algorithms stored in a database.
• Scattered light measuring system for the detection of smoke particles from a fire in combination with
• Distribution can be detected very precisely with the highly sensitive scattered light measuring system.
• gas sensors not only enable additional early detection
• the additionally arranged gas sensors are particularly well suited, Reliably detect fire gases arising at the start of a fire, such as CO H2, CH4, as well as longer-chain saturated and unsaturated hydrocarbons and sulfur compounds.
• a safe alarm is possible earlier than with the previously known self-priming systems.
• an alarm is only given and in different presettable stages when the signal evaluation of the optical scattered light measuring system reaches or exceeds certain threshold values and at the same time the gas sensor (s) detect fire gases.
• a broadband gas analysis of the aspirated air samples is possible by using several sensors that detect different types of gas or a sensor array.
• a further improvement in gas detection is possible by knowing the type of fire or smoldering gas to be expected from the surveillance area.
• the gas sensors to be provided for use in the fire alarm device can then be selected from a large number of different measuring cells (gas sensors) depending on the gases to be detected and allow the detection of very low gas concentrations in the ppb-
• the comparison and the weighting of the measured variables determined by the different fire detectors of the fire detection device according to the invention therefore enables early and reliable fire detection.
• Fire detectors also make it possible to characterize the course of the fire more precisely in terms of time and to carry out a fire course analysis.
• the fire alarm device according to the invention in a ventilation shaft or the like in which an air flow flows at a certain speed.
• Sampling can then take place e.g. B. through appropriately dimensioned openings in the housing of the fire detection device.
• Fig. 1 the fire detection device according to the invention with an intake pipe
• Fig. 2 is a flow chart for signal processing of the scattered light measuring system and additionally arranged detectors
• Fig. 3 is a block diagram of the individual system components of the fire alarm device
• FIG. 1 shows the fire alarm device 2 according to the invention, which is connected via the intake pipe 1 to the area of the plant or room which is to be monitored for a possible fire.
• a plurality of suction pipes with a plurality of suction openings can also be arranged, or the suction pipes can be designed as flexible hoses, the openings of which suck air even from system areas which are difficult to access.
• the air samples are sucked in continuously by means of a suction fan 3 with an adjustable constant flow rate and the measuring chamber
• Intake pipe network can be designed for lengths of up to 200 m, for example.
• a fault message is triggered in the event of impermissible deviations.
• Light source 4, receiver elements 6, 8 and focusing optics 5, 7 are each separated from the sample volume of the aspirated flue gas by plexiglass shields (not shown).
• the so-called bypass technique can also be used for areas of application with higher air speeds, such as exhaust air and air conditioning ducts.
• Air samples are constantly taken from the channel to be monitored via a pipe system and passed through the measuring chamber of the scattered light measuring system, where the gas sensors 9 can also be arranged. In the standard measuring setup shown in Fig. 1, this is highly sensitive
• Smoke particle measuring system 16 (FIG. 2) arranged at right angles to the air flow and shielded by the plexiglass panes mentioned.
• It consists of a high-energy sheep-light source, preferably a laser diode 4 with collimation optics to generate scattered light intensities
• Beam trap that absorbs the laser beam, as well as a collection
• the detection volume is to be kept as small as possible and is essentially determined by the intersection volume of the focal points of the
• the receiving elements 6, 8 and the collecting and focusing optics 5, 7 are arranged in such a way that the scattered light beams are detected from the solid angle segments of the forward direction and the backward direction.
• the forward and backward scattered light then generates in the receiver elements an electrical signal proportional to the received scattered light intensity which is processed and stored in the connected microcontroller system 13 and / or a fire alarm control panel 15.
• the measured values obtained according to this measuring principle are in relation to
• Smoke particle concentration but also particle properties such as shape, color and
• the high-energy light source for example laser diode
• the high-energy light source is controlled with a pulsed driver circuit, which increases the service life of the light source many times over.
• the modulated light pulses can only be triggered by the control electronics 13 if a new scattered light measurement is to take place.
• gases that are produced at an early stage such as CO, H2, CH4, and longer-chain saturated and unsaturated hydrocarbons and
• HCL fire-specific gases
• Decomposition of PVC can be reliably detected by using special gas sensors.
• the intelligent sensor according to the invention allows measurement variables of the gas sensor system
• the direction and intensity of the light scattered on a particle depend on its shape, color, and size as well as the light wavelength.
• Light portion 18 a statement that can be used for fire determination.
• Further scattered light detectors are preferably arranged in the angular range between 5 ° and 45 ° affected by strong changes in the intensity.
• one or more intensity indicators can be determined from vector sums of the angle-dependent scattered light intensities and one or more particle property indicators from the logarithmic ones
• Comparative data of permitted determined smoke properties are stored in the smoke aerosol database 21.
• the property vector obtained from 20 and the comparison data stored in FIG. 21 are then linked 22 to form the smoke identity number.
• the smoke scattered light intensity of the highly sensitive measuring circuit 23 is then in
• Method step 27 is evaluated with the measured variables determined by the gas sensor 24.
• the measurement variables of an optional smoke sensor (ionization smoke elder or optical smoke detector) 25 and / or an optional temperature detector 26 can also be included in the evaluation.
• the evaluation of the individual measured variables and the mutual dependency takes place with the aid of algorithms and comparative analyzes, which use data from test fires in a database 28.
• the further method then provides for the comparison of the sum signal obtained from method step 27 with pre-parameterized threshold values and, with corresponding comparison results, leads to activation and display of assigned alarm stages 29.
• Alarm levels of individual parameters can be provided in comparison with the assigned individual threshold value.
• a CO alarm can be triggered when a
• Fig. 3 shows the block diagram of the system components of the invention
• the two highly sensitive measuring circuits 32 and 33 each process those of
• the laser diode as the light source is driven in pulse form by a laser driver circuit 34, the pulses being supplied by the microcontroller system 13.
• the diode laser is advantageously only operated at the time of measurement, which leads to a multiplication of the laser life.
• the gas sensor system 35 and the optional temperature detector 37 are also via one A / D converter connected to the microcontroller system 13.
• the sample-and-hold circuit 36 which enables the scattered light measured values to be detected simultaneously by the trigger pulses of the microcontroller system.
• the microcontroller system 13 performs the analysis algorithms and evaluates gas and stray light measuring circuits, stores data and events, controls event-related displays and peripheral units, carries out communication with connectable peripherals 38 and compensates for environmental aerosol background drift of the sensitive stray light circles.
• microcontroller system for measurement control, data analysis and storage
• fire alarm control center building management system, control center PC
• gas sensor fire gas sensor
• sensor array e.g. CO sensor

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• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fire-Detection Mechanisms (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Fire Alarms (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2001
  • 2001-05-23 DE DE10124280A patent/DE10124280A1/de not_active Withdrawn
• 2002
  • 2002-04-15 WO PCT/DE2002/001385 patent/WO2002095705A1/fr not_active Ceased
  • 2002-04-15 AT AT02737792T patent/ATE292316T1/de active
  • 2002-04-15 DE DE50202632T patent/DE50202632D1/de not_active Expired - Lifetime
  • 2002-04-15 ES ES02737792T patent/ES2239232T3/es not_active Expired - Lifetime
  • 2002-04-15 EP EP02737792A patent/EP1389331B1/fr not_active Expired - Lifetime
  • 2002-04-15 CN CN02801569A patent/CN1462418A/zh active Pending

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