Automatic fire fighting system controls and extinguishes fire without human intervention. Examples of automated systems include fire spraying systems, gas fire prevention, and thickening of aerosol fire extinguishers. When fires are extinguished in the early stages of a minimal loss of life since 93% of all fire-related deaths occur after the fire has progressed beyond the initial stage.
Video Automatic fire suppression
Automatic system type
Currently there are many types of Automatic Fire Rescue Systems and standards for each. The system is as diverse as many applications. In general, however, Automatic Fire Suppression Systems falls into two categories: engineered and pre-engineered systems.
- The Fire Suppression System Engineering is the specific design and most commonly used for larger installations where systems are designed for specific applications. Examples include large land and sea vehicle applications, server space, public and private buildings, industrial paint lines, dye tanks and electrical switch rooms. Engineering systems use a number of gas or solid agents with many of them specifically formulated. Some are even stored as liquids and disposed of as gases.
- The Pre-Engineered Fire Control System uses previously designed elements to eliminate the need for engineering work beyond the original product design. Typical industrial solutions use wet or dry chemical agents, such as potassium carbonate or monoammonium phosphate (MAP), to protect relatively smaller spaces such as distribution boards, battery chambers, engine rooms, wind turbines, dangerous goods and other storage areas. A number of residential designs also appear that typically use water mist and target retrofit applications.
Maps Automatic fire suppression
Components
By definition, automatic fire suppression systems can operate without human intervention. To do so must have the means of detection, actuation and delivery. In many systems, detection is done mechanically or electrically. Mechanical detection using a fusible-link or thermo-bulb detector. These detectors are designed to separate at certain temperatures and release the tension on the release mechanism. Electrical detection uses a heat detector equipped with self-restore, normally open-close contact when a predetermined temperature is reached. Manual remote and local operation is also possible. Actuation usually involves a pressurized liquid and release valve, or in some cases an electric pump. Delivery is done by piping and nozzles. Special nozzle design for used agent and desired coverage.
Extinguishing agents
In the early days, water was the exclusive fire suppression agent. Although still in use today, water has limitations. In particular, its liquid and conductive properties can cause property damage as much as the fire itself.
Health and Environmental Issues
Despite its effectiveness, chemical fire extinguishers are not without losses. At the beginning of the 20th century, carbon tetrachloride was widely used as a dry cleaning solvent, refrigerant and as a firefighter agent. Later, found carbon tetrachloride can cause severe health effects. From the mid-1960s Halon 1301 was an industry standard to protect high-value assets from fire threats. Halon 1301 has many benefits as a fire suppression agent; this is fast acting, safe for assets and requires minimal storage space. The main disadvantage of Halon 1301 is that it exhausts ozone in the atmosphere and is potentially harmful to humans. Since 1987, about 191 countries have signed the Montreal Protocol on Substances that Deplete the Ozone Layer. This protocol is an international agreement designed to protect the ozone layer by stopping the production of a number of substances believed to be responsible for ozone depletion. Among these are halogenated hydrocarbons that are often used in fire suppression. As a result, manufacturers focus on alternatives to Halon 1301 and Halon 1211 (halogenated hydrocarbons). A number of countries have also taken steps to order the removal of the installed Halon system. Especially this includes Germany and Australia, the first two countries in the world to request this action. In both these countries, the complete removal of the installed Halon system has been completed, except for some important applications used. The EU is currently undergoing the abolition of a similar mandate from the installed Halon system.
History
The first fire-fighting patent was issued to Alanson Crane of Virginia on February 10, 1863. The first fire sprinkler system was patented by H.W. Pratt in 1872. But the first practical automated sprinkler system was invented in 1874 by Henry S. Parmalee of New Haven, CT. He installed the system at his piano factory.
Modern system
Since the early 1990s manufacturers have succeeded in developing safe and effective Halon alternatives. These include DuPont's FM-200, Halotron Pacific America, FirePro's FPC Compound and 3M's Novec 1230 Fire Protection Fluid. Generally, the current Halon replacement agent currently belongs to two broad categories, in-kind (gas extinguishers) or not in-kind (alternative technologies). In-kind gas agents generally fall into two further categories, halocarbons and inert gases. Not an alternative in form including options such as water mist or use of early warning smoke detection systems.
References
https://www.epa.gov/snap/substitutes-total-flooding-agents
Source of the article : Wikipedia
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