How to choose a fire detector?

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General provisions

First, the selection of fire detectors should meet the following requirements :

1. Fire smoke detectors should be selected for places where there are smoldering stages at the beginning of the fire, where large amounts of smoke and a small amount of heat are generated, and little or no flame radiation occurs.

2. Fire-sensitive heat detectors, smoke detectors, flame detectors, or combinations thereof can be selected for locations where fires develop rapidly and where large amounts of heat, smoke, and flame radiation are generated.

3 , the rapid development of the fire, there is a strong flame radiation and a small amount of smoke, hot places, should choose the flame detector.

4. Carbon monoxide fire detectors should be added to sites where there is a smoldering stage in the early stages of the fire and where early detection is required.

5. For combustible gas or flammable vapors, the combustible gas detector should be selected.

6. The corresponding fire detectors should be selected according to the analysis of the locations where the fire may occur in the protected place and the burning materials, and the type, sensitivity and response time of the fire detectors. The places where the characteristics of fire formation are unpredictable can be simulated. The result is a fire detector.

7. When multiple fire detectors are installed in the same detection area, fire detectors and fire alarm controllers with composite judgment fire function can be selected.

Point fire detector selection

First, for rooms of different heights, you can select point-type fire detectors according to the following table.

Second, the following places should choose point type smoke fire detectors :

1. Halls, bedrooms, offices, shopping malls, train passenger carriages, etc. of restaurants, hotels, teaching buildings, and office buildings.

2 , computer room, communication room, movie or television screening room.

3 , stairs, walkways, elevator room, garage and so on.

4 , library, archives and so on.

3. Spot smoke fire detectors should not be selected in places that meet one of the following conditions :

1 , relative humidity is often greater than 95 %.

2. The air velocity is greater than 5m /s .

3 , there is a lot of dust, water droplets.

4 , may produce corrosive gas.

5. Smoke retention under normal conditions.

6 , produce alcohols, ethers, ketones and other organic substances.

(4) Point-type photo-electric smoke detectors should not be selected in places that meet one of the following conditions :

1 , there is a lot of dust, water droplets.

2 , may generate steam and oil mist.

3 , high altitude areas.

4. Smoke stays under normal conditions.

5. Spot heat-sensing fire detectors shall be selected in places meeting one of the following conditions; and appropriate types of heat-sensing fire detectors shall be selected according to the typical application temperature and the highest application temperature of the place of use :

1 , relative humidity is often greater than 95 %.

2. Smokeless fire may occur.

3 , there is a lot of dust.

4. Places where smokers or vapors are trapped under normal conditions, such as smoking rooms.

5 , kitchen, boiler room, generator room, drying workshop, etc. should not install smoke fire detectors.

6. It is necessary to cooperate to extinguish the inside of the safety exit of the “safe exit” indicator light.

7. Other places that are not stranded and are not suitable for installation of smoke detectors, but where there is a need for timely warning in case of fire.

6. Sites that may cause smouldering fires or fires that do not promptly cause serious losses will not be suitable for spot-type heat detectors ; locations with temperatures below 0 °C should not be used for constant temperature detectors ; locations with large temperature changes The detector with differential temperature characteristics should not be selected.

(7) Point-type flame detectors or image-type flame detectors should be selected in places that meet one of the following conditions :

1 , There is a strong flame radiation in the fire.

2. There may be fires with no smoldering stage such as liquid combustion.

3 , need to make a quick response to the flame.

8. Spot flame detectors and image flame detectors should not be selected in places that meet one of the following conditions :

1. Smoke spreads before the flames appear.

2. The detector's lens is easily contaminated.

3 , the detector's "line of sight" is easily covered by oil mist, smoke, water fog and ice and snow.

4. The combustibles in the detection area are metal and inorganic.

5. The detector is susceptible to direct or indirect light sources such as sunlight and incandescent lamps.

9. In areas where there are high-temperature objects under normal conditions in the detection area, single-band infrared flame detectors should not be selected.

X. UV flame detectors should not be selected where there is an open fire under normal circumstances and the detector is susceptible to X -rays, arcs, and lightning.

Eleven, the following places should choose combustible gas detectors :

1 , the use of combustible gas places.

2. Gas stations, gas watch houses, and places for storing liquefied petroleum gas tanks.

3. Other places emitting combustible gas and flammable vapors.

XII. Point carbon monoxide fire detectors may be selected at the following locations where carbon monoxide is produced in the early stages of a fire :

1 , smoke is not easy to convection or place with a thermal barrier below the roof.

2. The location of other point type fire detectors cannot be installed on the roof.

3 , the need for multiple signal composite alarm place.

13. Sites where there is a lot of dirt and smoke detectors must be installed, point-sampling air-sucking smoke detectors that intermittently inhale should be selected, or pipelines with filter and pipeline self-cleaning functions should be selected. Gas smoke detector.

Linear fire detector selection

One, unobstructed large space or room with special requirements, should choose the linear beam smoke detector.

Second, in line with one of the following conditions, should not choose the linear beam smoke detector :

1 , there is a lot of dust, water droplets.

2 , may generate steam and oil mist.

3 , smoke retention under normal conditions.

4. The structure of the fixed detector will generate a large displacement due to vibration and other reasons.

Third, the following places or parts, should choose cable type heat detector :

1 , cable tunnels, cable shafts, cable mezzanines, cable trays.

2. It is not easy to install the sandwich detector and stuffy top of point detector.

3 , a variety of belt conveyor device.

4 , other bad environment is not suitable for installation of point detectors.

Fourth, the following places or parts, should choose the linear fiber temperature heat detector :

1. Oil storage tanks other than liquefied petroleum gas.

2. It is necessary to set the flammable and explosive place of the linear temperature-sensing fire detector.

3 , the need to monitor the ambient temperature underground space and other places should be set with a real-time temperature monitoring function of the linear optical fiber temperature detector fire.

4. Highway tunnels, railway tunnels with power cables and urban subway tunnels.

Fifth, the selection of line-type constant-temperature fire detectors should ensure that the non-operating temperature meets the requirements of the maximum ambient temperature at the installation site.

Selection of Aspirating Smoke Detectors

First, the following places should choose aspirated smoke detector :

1. Location with high-speed airflow.

2 , point-type smoke, heat detectors are not suitable for large space, the stage above the building height of more than 12m or have special requirements.

3 , low temperature places.

4. Locations where hidden detection is required.

5. Important sites for early detection of fires are required.

6. Sites where people should not enter.

2. In places where the dust is relatively large, pipeline-sampling suction smoke detectors that do not have filters and pipeline self-cleaning functions should not be selected.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.

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