RU29391U1 - Combined fire detector "IPK-TU" - Google Patents

Description

Combined fire detector IPK-TU.

The invention relates to fire alarms, specifically to combined fire detectors.

Known fire detector combined G.M. Karnaukhov, E.A. Karnaukhova. "Methods for improving the noise immunity of fire alarm systems of vehicles in the book. “Large fires: prevention and suppression. - M :, Federal State Institution VNIRSHO of the Ministry of Internal Affairs of Russia, Materials of the XVI Scientific and Practical Conference, 2001 p. 216-218, comprising a device for generating fire signals with smoke and heat sensors, wherein the smoke sensor is closed by a light shield provided with slots for smoke. A heat sensor is installed on the body of the fire signal generation device.

However, the known detector has insufficient reliability due to the possibility of light entering the smoke detector through the slots in the screen.

The basis of the present invention is the task of creating a fire detector combined with enhanced reliability.

The solution to this problem is achieved by the fact that in a combined fire detector containing a device for generating fire signals with smoke and heat detectors, the smoke detector is closed by a light shield equipped with slots for smoke, according to a utility model, the heat detector is made on heat-sensitive elements and assembled on an electronic board mounted on a light-shielding screen above the smoke slots with a clearance of mm.

heat-sensitive elements, the heat sensor contains thermistors or thermocouples with cold and / or hot junctions. The smoke detector contains an infrared emitter, an infrared receiver of useful signals, an infrared receiver of noise background, the outputs of the infrared receivers are connected through an interference compensator, an amplifier, and a threshold device with the detector output. The RG emitter and IR receiver are made with intersecting radiation and reception patterns, respectively, by installing them on the lateral sides of a lightproof partition made of a triangular section with an angle of inclination of the faces of 20 - 70 °. The IR - receiver of the noise background is made with a reception diagram in the range of 2–15 °, oriented out of sight of the radiation pattern of the IR emitter.

The introduction of these differences allows you to reduce the level of false alarms of the detector and, thereby, increase the reliability of its work.

In FIG. 1 is a drawing explaining the design of the detector; FIG. 2 - its functional diagram; in FIG. 3 - design of a heat sensor.

The combined fire detector comprises a fire signal generating device 1 with a smoke sensor 2 and a heat sensor 3. The smoke sensor 2 is closed by a light shield 4 provided with slots 5 for smoke. The heat sensor 3 is made on heat-sensitive elements 6 and assembled on an electronic board 7 mounted on a light-shielding screen 4 above the slots 5 for smoke. The board 7 is installed above the surface of the light shield 4 with a gap of H5 mm.

In this case, slots 5 for smoke are made in the upper part of the light-shielding screen 4 and are covered by an insect net 8. As heat-sensitive elements, the heat sensor 3 contains thermistors or thermocouples with cold 9 and / or hot 10 junctions. The smoke detector 2 contains a pulsed IR emitter And, an IR receiver 12 useful signals, an IR receiver 13 noise background. The outputs of the RJ - receivers 12 and 13 are connected through a compensator 14 interference, the amplifier 15 with the first input

threshold device 16, the second input of which is connected to the output of the heat sensor 3. The output of the threshold device 16 is the output 17 of the detector. The RG-emitter 11 and the IR-receiver 12 are made with intersecting radiation and reception patterns, respectively, by installing them on the side faces of the opaque partition 18. The partition 18 is made of triangular cross-section with an angle of inclination of the faces 20 -70 °.

The IR receiver 13 of the noise background is made with a reception diagram in the range of 2 - 15 °, oriented out of sight of the radiation pattern of the IR emitter 11. The IR detectors 12 and 13 are made on the same photodiodes. The radiation patterns of the IR emitter 11 and IR receivers 12 and 13 are formed by installing the appropriate diaphragms or forming optics. The outputs of the IR - receivers 12 and 13 are connected counterclockwise to the inputs of the equalizer 14 interference. The compensator 14 is made in the form of a series-connected current amplifier of the differential signal and the current to voltage converter. The output of the compensator 14 through the amplifier 15 and the threshold device 16 is connected to the output 17 of the detector.

The work of the fire detector is as follows.

The emitter 11 periodically emits IR pulses. When smoke enters through slots 5 in the screen 4 of the smoke sensor 2 into the intersection zone of the radiation patterns of the IR emitter I and the IR receiver 12, the latter receives IR signals reflected from the smoke particles and provides an appropriate electrical signal to the first input of the interference canceller 14. At the same time, the second input of this compensator receives a scattered infrared noise signal from the inside of the screen 4. Due to the on-off switching of the IR receivers 12 and 13, the interference compensator 14 compensates for thermal and background noise. In addition, with the smoke of the inner part of the screen 4, the input signal at the input of the IR receiver 13 decreases and an additional uncompensated smoke signal appears at the input of the compensator 14.

the compensator 14 is the amplification of the current of the differential signal and the conversion of direct current into voltage. The voltage of the signal from the output of the compensator 14 through the amplifier 15 is fed to the input of the threshold device 16. At the same time, in the presence of a fire, the heat sensor 3 generates an electrical signal that exits to the second input of the threshold device. If the parameters of the signals at the inputs of the threshold device 16 threshold values are exceeded, the latter generates a fire alarm.

The authors developed a prototype detector. Preparing its industrial development.

Claims (8)

1. Combined fire detector containing a fire signal generating device with smoke and heat sensors, wherein the smoke sensor is closed by a light shield equipped with slots for smoke, characterized in that the heat sensor is made on heat-sensitive elements and assembled on an electronic board mounted on a light shield above the smoke slots with a gap of 1 ÷ 5 mm. 2. The detector according to claim 1, characterized in that the slots for smoke are made in the upper part of the light shield and are covered with an insect net. 3. The detector according to claim 1, characterized in that as heat-sensitive elements, the heat sensor contains thermistors or thermocouples with cold and / or hot junctions. 4. The detector according to claim 1, characterized in that the smoke detector contains an infrared emitter, an infrared receiver of useful signals, an infrared receiver of a noise background, while the outputs of the infrared receivers are connected through an interference compensator, an amplifier, and a threshold device with the detector output. 5. The detector according to claim 4, characterized in that the infrared emitter and infrared receiver are made with intersecting radiation and reception patterns, respectively. 6. The detector according to claim 5, characterized in that the IR emitter and IR receiver are mounted on opposite side faces of the opaque partition. 7. The detector according to claim 6, characterized in that the lightproof partition is made of a triangular section with an angle of inclination of the faces of 20 ÷ 70 °. 8. The detector according to claim 1, characterized in that the infrared receiver of the noise background is made with a reception diagram in the range of 2-15 °, oriented out of sight of the radiation pattern of the infrared emitter.