Inhibition (fire brigade)
In fire brigade jargon , inhibition ( Latin inhibere , to stop) is the so-called “anti-catalytic extinguishing effect”, which is intended to interrupt a combustion process.
Anti-catalytic extinguishing effect
In the fire service literature, an anti-catalytic extinguishing effect is understood as an extinguishing agent that emerges unchanged from a reaction, i.e. is not used itself. The term anti- catalyst cannot be understood analogously to the term catalyst from chemistry. Because a chemical catalyst accelerates a reaction without being changed. An "anti-catalyst" would therefore be a substance that slows down a reaction and does not change in the process. This is hardly the case with extinguishing agents, see also flame retardants .
The so-called "anti-catalytic extinguishing effect" comes into play with fire classes B and C, mostly flame fires, and is the main extinguishing effect with the extinguishing agents powder and halon .
Types of inhibition
In simplified terms, a distinction is made between two types of inhibition: homogeneous inhibition (extinguishing agent: e.g. halon and flammable substance: e.g. natural gas, have the same physical state ) and heterogeneous inhibition (extinguishing agent: e.g. extinguishing powder and flammable substance : e.g. gasoline - greatly simplified, have different physical states).
Homogeneous inhibition
Halon, which breaks down in the flame, causes the formation of radicals . These generate a chain termination reaction (so-called recombination ), which makes further combustion impossible.
Heterogeneous inhibition
The so-called radicals are rendered harmless by the large surface area in the total number of extinguishing powder and the combustion reaction is stopped suddenly. The heterogeneous inhibition is also referred to as the “wall effect”.
literature
- Roy Bergdoll, Sebastian Breitenbach: Die Roten Hefte, Issue 1 - Burning and Extinguishing . 18th edition. Kohlhammer, Stuttgart 2019, ISBN 978-3-17-026968-2 .
- Ludwig Scheichl, fire theory and chemical fire protection, Hüthig-Verlag, 2nd edition, 1958 (p. 249, 325 f.).
- Alfons Rempe, fire extinguishing agent - properties, effect, application, Kohlhammer-Verlag, 6th edition, 1997 (p. 28 f., P. 107 ff., P. 127 ff.).
Individual evidence
- ↑ Duden | Inhibition | Spelling, meaning, definition, origin. Retrieved January 17, 2018 .
- ^ Voluntary fire brigade Werder: Fire brigade lexicon. Retrieved January 17, 2018 .
- ↑ Copyright Haufe-Lexware GmbH - all rights reserved: Defensive fire protection: Burning and extinguishing / 2.3.3 Extinguishing powder | Occupational Safety Office | ... In: Haufe.de News and Expertise . ( haufe.de [accessed on January 17, 2018]).
- ↑ Haufe occupational safety