It is used to extinguish fires in hot kitchen processing equipment, oil collecting hoods and exhaust ducts in kitchen equipment. It consists of fire extinguishing agent storage container components, driving gas storage container components, pipes, sprinklers, valves and their driving devices, fire detectors, and controls. A complete system that can automatically detect and implement fire suppression.
2.2 Setting place
The kitchens in public buildings such as hotels, restaurants, restaurants, institutions, schools, enterprises and public institutions meet one of the following conditions. Automatic fire extinguishing systems for kitchen equipment (abbreviated as kitchen equipment) should be provided, and water mist fire extinguishing systems for kitchen equipment should be provided:
1) A kitchen in an underground building.
2) A kitchen located in or adjacent to a supermarket with a construction area of 1000 m2 or more.
3) In high-rise buildings, kitchens with dining area ≥ 200m2.
4) In hotels, restaurants, restaurants, institutions, schools, enterprises, and other public buildings and restaurants with a business area of ≥ 500m2, the oil fume hood and cooking part of the cooking operation room should be equipped with automatic fire extinguishing devices, and kitchen equipment can be installed Fog fire extinguishing system.
2.3 System Features
Modern catering industry has the characteristics of high energy input cooking equipment and high spontaneous combustion temperature cooking oil. Commercial and public catering cooking room fires have increasing potential risks to life and property. Fires caused by kitchen equipment and collecting and exhausting fume devices happens sometimes. Compared with other types of fires, edible oil fires have their own characteristics and are not easy to extinguish. In addition to extinguishing the flame on the surface of edible oils, they must also cool the edible oils to a newly formed spontaneous combustion temperature lower than the original spontaneous combustion temperature. In the following, prevent re-ignition. The water mist fire extinguishing system is very effective for extinguishing edible oil fires. This system is non-toxic and does not cause environmental problems.
2.4 Main technical parameters
1) The design spray intensity, continuous spray time and cooling water supply intensity shall meet the requirements of Table 2.4.
2) Fine water mist refers to the water spray of the nozzle under the minimum working pressure, measured on a plane 1.0m downward from the nozzle axis, with a cumulative volume distribution of droplet diameter DV0.99 <1000µm, and DV0.5 <300µm.
Table 2.4 Design spray intensity, continuous spray time and cooling water supply intensity
2.5 System Design Points
1) The minimum working pressure of the sprinkler at the most unfavourable point of the fire extinguishing system should not be less than 0.40MPa.
2) When supplying cooling water, the minimum working pressure of the sprinkler at the most unfavourable point of the fire extinguishing system should not be less than 0.10MPa.
3) The protection area of the fire protection system protection object shall be determined according to its surface area and meet the following requirements:
(1) Deep fryer and wok should be determined according to their maximum projected area. When a flat stove is set on the cooktop, it can be calculated and determined according to the area of the cooktop it occupies.
(2) The protection area of the oil fume hood should be determined according to the internal surface area of the oil fume hood.
(3) The protection area of the exhaust duct shall be determined by calculating the internal surface area of the flue before the fire damper.
4) The kitchen fire extinguishing system can adopt single fluid system or dual fluid system.
5) The quality of the filled fire extinguishing agent should meet the sanitary standards of drinking water. The driving gas (atomizing medium) should be nitrogen or other inert gas, and compressed air should not be used. 6) The number of nozzles of the fire extinguishing system should be based on the design spray intensity, protection area and nozzle characteristics, and can refer to the "Code for Design, Construction and Acceptance of Fine Water Mist Fire Extinguishing System for Kitchen Equipment"
DB51 / T 592-2006 Specification 5.1.2 Calculation and determination.
7) The effective capacity of the water fire extinguishing agent storage container should be able to meet the spray intensity and continuous spray time of the spray nozzles of the kitchen fire extinguishing system. The effective volume of the drive gas storage container should be (0.6 to 1.0) times the effective volume of the water fire extinguishing agent storage container.
8) A protective area can be protected by one kitchen fire extinguishing system, or by multiple kitchen fire extinguishing systems.
9) When a fire occurs in a certain section of the protection zone, all sprinklers arranged in this section of the zone shall be sprayed with fine water mist at the same time to extinguish the fire. After the fire extinguishing agent is discharged, the cooling water supply valve should be automatically opened quickly, and the sprinkler should simultaneously discharge the cooling water to continue to cool down.
10) The response time of the fire suppression system should not be greater than 30s.
11) When the fire extinguishing system is started, the power of the kitchen equipment should be quickly and automatically cut off, the fuel valve and the smoke exhaust fire valve should be closed.
12) The fuel supply pipeline shall be provided with automatic and manual shut-off valves before entering the building and in the equipment room.
13) The selection of pipes is the same as the sprinkler system.
2.6 System components
System components are: fire extinguisher storage bottle, drive gas storage bottle, bottle head atomizer, fine water spray nozzle, check valve, valve driving device, fire detector, combustible gas detector (optional), control cabinet Wait.