Foam closed system

Basic definition

• The foam closed system is a foam water sprinkler system with a closed sprinkler. The sprinkler is equipped with a thermosensitive element (glass ball or fusible alloy), which is usually closed. Only when the temperature of the fire area reaches the set value can the foam mixture be sprayed. The system has both foam extinguishing and water spray cooling functions, which can precisely extinguish the fire at the point of ignition. It is a “local response” fire extinguishing system.

Core components

1. Closed nozzle: special nozzle with thermal sensor, divided into standard type and foam special type, with operating temperature of 68 ° C, 93 ° C or 141 ° C
2. Alarm valve group: Wet type alarm valves are commonly used to maintain pressure water in the pipeline network. After the nozzle is activated, the alarm will automatically start and the fire pump will be activated
3. foam concentrate supply device: including foam concentrate storage tank, capsule and proportioner to ensure that foam concentrate and water are mixed in proportion
4. Water flow indicator: Each fire compartment is equipped with one to provide feedback on the specific location of the fire area
5. Pressure switch: linkage start fire pump and foam liquid supply device
6. Automatic fire alarm system: Some systems can be combined with fire detectors to achieve pre start and improve response speed

Princípio de funcionamento

1. Fire occurrence: The temperature in the ignition area rises to the operating temperature of the closed nozzle thermal sensor
2. Nozzle opening: The thermal sensor ruptures, the closed nozzle opens, and the pressure inside the pipeline decreases
3. System startup: the pressure switch of the alarm valve group acts, and the fire pump and foam proportioner are started in linkage
4. foam injection: the foam mixture is sprayed to the fire area through the open nozzle, and the foam covering suffocation is used to extinguish the fire
5. Manual cooling: After the fire is extinguished, it can be manually switched to water spray mode to cool the fire area and prevent reignition
6. System reset: Replace damaged nozzles, drain excess water from the pipeline network, and restore the system to standby mode

Core strengths

• Accurate firefighting and efficient utilization of resources

1. Only the sprinkler in the fire area is opened to avoid waste of water resources and foam liquid caused by whole area spraying
2. The water flow indicator can accurately provide feedback on the fire area, making it easy for firefighters to quickly locate the fire situation

• Low operation and maintenance costs, easy to maintain

1. The probability of damage to the closed nozzle is low, and only the nozzle after action needs to be replaced, without the need for large-scale maintenance
2. The pipe network is usually filled with pressure water, and routine maintenance only needs to check the water pressure and the validity period of foam liquid regularly

• Wide applicability and strong scene compatibility

1. Can be used for relatively enclosed small spaces or combined for zoning protection of large buildings
2. Support the combination of wet, dry, pre action and other spray systems

• Reduce secondary losses and protect property safety

1. Local spray mode can minimize the impact of water stains on property in non fire areas to the greatest extent possible
2. Suitable for places sensitive to water damage, such as archives, precision instrument rooms, etc

• Flexible design and strong customizability

1. Nozzles with different operating temperatures can be set up according to different locations to meet special environmental requirements
2. Support strengthening local protection and increasing nozzle density in high-risk areas