Chemical extinguishing system
Chemical extinguishing systems achieve their extinguishing effect by extracting heat from the flame . They are therefore safer for people and animals than conventional gas extinguishing systems that rely on oxygen displacement.
Halon ban / halon substitute
Since 2004, civilian applications with the extinguishing agent halon (in the traditional sense) are no longer permitted because it destroys the ozone layer . Therefore, alternative extinguishing agents have been developed by various companies, often referred to as halon substitutes. The extinguishing system can often be converted to these extinguishing agents through minor technical changes.
Examples
Two examples of chemical extinguishing agents :
- With the extinguishing agent known under the ISO designation HFC-227ea (brand names: FM-200 from Great Lakes Chemicals, FE-227 from DuPont Corporation and Solkaflam 227 from Solvay Fluor GmbH), the heat is extracted from the fire through mostly physical action (cool) and little chemical intervention in the combustion process. With this extinguishing agent a quick extinguishing effect is achieved. The lifetime of HFC-227ea in the atmosphere is approximately 33 years. There are hardly any restrictions on use of this extinguishing agent as long as the extinguishing area is relatively tight in order to achieve and maintain the necessary concentration of extinguishing agent. At high temperatures, however, undesirable decomposition products can arise during the extinguishing process, which should be viewed as critical to health.
- Novec 1230 (brand name of 3M Corporation) is a particularly environmentally friendly chemical extinguishing agent and is degraded in the atmosphere within approx. 5 days. It is considered to be relatively future-proof as it neither destroys the ozone layer nor drives global warming. At room temperature, Novec 1230 , a liquid which is easy to a gas when it flows evaporated under pressure from the nozzles. Fast, effective extinguishing processes with a high penetration capacity are possible (ten seconds) and there are no residues of the extinguishing agent. With this extinguishing agent, a relatively dense extinguishing area is required to effectively extinguish or flood an extinguishing area. The extinguishing agent is particularly suitable for use in areas occupied by people, as there is no risk of suffocation if the concentration is effective. At high temperatures, however, undesirable decomposition products can arise during the extinguishing process, which are to be viewed critically in terms of health, as the extinguishing agent contains fluorine. The use of Novec 1230 is predestined for telecommunication facilities and server rooms, since the extinguishing agent is not electrically conductive. It also makes sense to use it in archives, museums and libraries, but there are still comparatively few specifications in the relevant guidelines such as DIN EN 15004 or VdS 2381.