1. Because the droplets ejected by the impact nozzle of the medium-speed water mist nozzle are relatively thick, it can be used to protect the dangerous areas of flammable liquids, gases and solids with a flash point above 66 °C. Medium-speed water mist sprinklers have the characteristics of limiting burning speed, reducing fire damage, reducing explosion hazard, and promoting steam dilution and emission.
The medium-speed water mist nozzle is mainly used for protective cooling. When the protective cooling is used, the momentum of the spray is required to be relatively small and the particle size of the droplet is relatively large. Therefore, it is necessary to provide a lower water pressure to the water mist nozzle, and the inlet pressure is 0.15 ~ 0.5MPa , the droplet size is 0.4 ~ 0.8mm. The atomization degree of the impact type water mist nozzle is relatively poor, and the electrical insulation of the mist water cannot be ensured, so it is not suitable for fighting electrical fires.
2. Because the droplets ejected by the high-speed water mist nozzle are relatively fine, it is used to extinguish flammable liquids above 60°C, and can protect the outer surface of the object to form a covering space. High-speed water mist sprinklers have the characteristics of cooling, suffocation, fire suppression and extinguishing. When extinguishing the fire, the momentum of the spray is required to be relatively large and the particle size of the droplets is relatively small, so it is necessary to provide a high water pressure to the water mist nozzle, and the inlet pressure is 0.25-0.8MPa and the particle size of the water droplets is 0.3-0.4mm.
Because the water droplets ejected by the high-speed water mist nozzle are discontinuous and intermittent water droplets, which have good cable insulation properties, they can effectively extinguish electrical fires, and are non-conductive at the same time. They are very suitable for use in water spray fire extinguishing systems for protecting electrical facilities.