Automatic fire suppression is an engineering or pre-engineered system that allows the extinction of incipient fire during the first minutes of its generation, automatically to safeguard people, goods, and properties in a fast and effective way.
An automatic fire suppression system requires precise calculations and designs that properly determine the necessary discharge flow, quantity and type of discharge nozzles, size of the pipes, area to be covered by each nozzle, and the amount of agent needed for each area.
During the discharge, the gas or agent is automatically spread throughout the area that is burning to extinguish the fire in a short time without electrical risks and without putting the lives of more people at risk and to avoid damage to equipment and/or facilities.
The most commonly used agents in automatic fire suppression systems are clean gases (carbide halos) and inert gases.
Most of the fire suppression systems are constituted by the following elements and devices:
- Control panel for fire suppression.
- Uninterruptible electrical power.
- Clean extinguishing agent.
- Cylinder bank with a clean agent (main and reserve).
- Cylinder frame or harness.
- Discharge heads.
- Pressure operated discharge valves, control heads, and hoses.
- Metal pipe and discharge nozzles.
High-pressure switch, detection,
or remote manual download station,
or remote manual abortion station,
or manual remote trigger station,
or status lights, audible alarms, etc.
Form of Action
When the system detects smoke or heat particles the detection system activates the prevention alarm (visual and audible), sending a signal to the control panel indicating the zone with the presence of smoke or heat.
If the alarm remains, the signal reaches the electric actuator that activates the cylinders to release the gas contained.
The electrovalves allow the agent to be directed only to the area at risk, allowing the fire to be suppressed quickly and effectively.
Gas-based suppression systems are usually complemented with automatic ventilation shutdown and electrical power cut elements.
Most of these types of systems suppress the fire by reducing the oxygen in the risk area to the necessary limits without affecting the oxygenation levels for the human being.
In some cases it is necessary to evacuate the area immediately, considering the characteristics of the agent used.
There are different types of suppression systems, according to the extinguishing agent used:
- Clean agents
- Carbon dioxide (CO2)
- Dry chemical powder
- Pressurized water
NFPA recommends certain gases on fire suppression systems because they are safer as they do not conduct electrical energy and do not leave residues after discharge.
Generally, gas suppression systems cover the following options:
- They protect enclosed areas where a rapid reaction to a fire is required and where people may be present.
- They protect areas where a fire may break out during the day or at night.
- They cover areas where damage from conventional agents cannot be allowed.
At present, it is intended that the types of clean suppression agents should be harmless to the environment and humans. They should have a ZERO ozone depletion potential, a ZERO global warming potential, and life in the atmosphere equal to ZERO. Therefore, they should be environmentally friendly.