Description and Applications
The shutdown systems to aerosols for the extinction of fires, using a fine suspension of particles having the consistency of a very fine powder, which usually is formed from potassium nitrate.
These systems utilize fact, to obtain the objective to extinguish the fire a mechanism mainly of chemical inhibition of combustion in addition to physical.
The system of generation of dust is guaranteed by aerosol dispensers, typically steel containers of various weights. Through a process of internal combustion triggered by an ignition device and subsequent cooling guaranteed by magnesium that, because of the high temperatures (120 ° / 130 °) reacts transformed into magnesium oxide, thus freeing H2O, dispense into the environment from protect the suspension with a certain force of expulsion which also favors the dispersion.
The compound that forms the aerosol is classified as a dangerous substance “Class 4.1 ” with the Classification Code of the United Nations Dangerous Goods (ADR).
The systems are mainly of two types, the first to localized application, which position the generators at particular points in such a way that the dispensing interests a specific possible outbreak of fire, and the second to total saturation, in which the generators are positioned in homogeneously throughout the volume to be protected, in order precisely to saturate all the same volume with the aerosol.
Currently the most popular types of aerosols are condensed, in which the aerosol is generated by the controlled combustion of potassium in an appropriate container, other as the dispersed using aerosols already formats, that are brought into the environment to be protected via a carrier gas.
Are valid for the control of fires both class A and class B in confined spaces and of small dimensions. An obvious limitation to their use is currently a lack of a recognized technical standards and uncertainties that exist in relation to the potential toxicity of the aerosol and the concentrations used for extinction.
The regulations in phase at the time of study limit the use exclusively to unoccupied areas.
The elements to ensure protected areas from extinguishing systems for aerosol total flooding are mainly:
- deactivation system manual of the entrance of the protected area;
- A design that identifies the location of the manual release
- Vie output always available
- signs of exit routes;
- system Emergency lighting
- self-closing doors;
- Audio and visual alarms inside and outside the area to be protected;
- Warning signals and safety instructions
- Automatic alarm pre-release;
- devices also forced ventilation of the protected area to be activated after release;
- Education and training of all staff and personnel of the maintenance companies