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24
2023
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05
Fire Extinguishing Mechanism of High Pressure Water Mist Fire Extinguishing System
Source:
Umara Technology
1. High-efficiency cooling effect: Since the droplet diameter of the fine water mist is very small, the diameter of the mist particle in the ordinary water mist system is 10-100 μm. During the process of vaporization, it absorbs a large amount of heat from the surface of the burning object or the fire area. Based on the latent heat of evaporation of water at 100°C as 2257kJ/kg, the heat absorption power of water mist sprayed by each nozzle (water spray speed 0.133L/s) is about 300KW. Experiments have shown that the smaller the diameter, the greater the heat absorption per unit area of the water mist, the faster the droplet velocity, the smaller the diameter, and the higher the heat transfer rate.
2. Suffocation effect: After the fine water mist is sprayed into the fire site, it evaporates rapidly to form steam, and the volume expands sharply by 1700-5800 times, reducing the oxygen volume fraction and forming a barrier around the burning material to prevent the inhalation of fresh air. With the rapid vaporization of water, the water vapor content will increase rapidly, and at the same time, when the oxygen content decreases to 16% to 18% in the space around the fire source, the flame will be suffocated. In addition, the fog droplets in the non-combustion area outside the fire site will not vaporize, the oxygen content in the air will not change, and it will not endanger the lives of personnel.
3. Block radiant heat: After the high-pressure water mist is sprayed into the fire site, the steam formed by evaporation quickly covers the combustion, flame and smoke, and has an excellent ability to block the radiant heat of the flame, which can effectively inhibit the radiant heat from igniting the surrounding area. Other items to achieve the effect of preventing the spread of flames. The attenuation effect of water mist on radiation can also be used to protect the lives of firefighters.
4. Dilution, emulsification, and wetting: the droplets with large particles and high impulse will impact the surface of the burning material, so that the burning material can be soaked, and the further generation of solid volatile combustible gas can be prevented, so as to achieve the purpose of extinguishing the fire and preventing the spread of the fire. In addition, the high-pressure water mist also has the functions of washing smoke and exhaust gas, emulsifying and diluting liquids, etc.
Key words:
Straight wire drawing machine/water tank wire drawing machine/inverted wire drawing machine/annealing furnace/winding unit/rewinding machine
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