Fires on waste dumps, surface landfills, Underground stowing or storage facilities of Recycling factories may have multiple harmful effects on individuals on site and on environment.
Possibly several tens of thousands of tons flare up plunging vast areas in smoke and releasing large amounts of flue gases. Experience shows that fire fighting takes days or even weeks and moreover, as long as hidden glowing nests exist fires may break out repeatedly weeks or months later. In the light of this, fire prevention is much easier to manage than extinction. It is of internst to identify the geometrical and physical conditions under which the mid-term or long-term storage of recycling materials can be performed avoiding self-ignition. Our Guideline presents a novel method developed at BAM which combines experimental tests on lab-scale with numerical simulations in Order to obtain permissible geometries of deposits and storage times at which self-ignition can be certainly avoided (Berger 2010).
Chemical-analytical investigation of fire products in intermediate storages of recycling materials
(2012)
Organic materials like paper, cardboard, textiles or plastics are mostly flammable. In intermediate storages for recycling products, these materials are stored in large amounts. If fire occurs in these stores, large emissions of smoke and other potentially harmful products are likely. In the present study, the gaseous products released from fires of such materials—for example, because of self-ignition—were investigated. Different fractions (paper/cardboard, textiles and plastics) were crushed at low temperatures (about 80 K) and subsequently allowed to smoulder at different temperatures using the German standard Deutsches Institut für Normung 53436. The gases produced were sampled and analysed using Fourier transform infrared spectroscopy. The chemical composition of these gases differed considerably depending on fuel type. For flammable materials without heteroatom, the gases consisted predominantly of toxic compounds like carbon monoxide and carbon dioxide. Smouldering of materials containing heteroatoms showed, in addition to carbon monoxide, carbon dioxide and water vapour, further toxic components containing the heteroatom. Materials containing chlorine produced hydrogen chloride, and materials containing nitrogen produced ammonia and hydrogen cyanide.
The hazards for passengers during vehicle fires result from the increasing temperature and the emitted smoke gases. A fire was set on a car to investigate the development of temperature and of gaseous fire products in the passenger compartment. The study was based on a full-scale test with a reconstructed scene of a serious car fire. The aim of this work was to identify the conditions for self-rescuing of passengers during a car fire.
A dummy, equipped with several thermocouples, was placed on the driver’s seat. Also, the smoke gases were continuously collected through a removable probe sensor corresponding to the nose of the dummy in the passenger compartment and analyzed using Fourier transform infrared spectroscopy. Additionally, several car components were investigated in the smoke density chamber (smoke emission and smoke gas composition). It was found that the toxic gases already reached hazardous levels by 5 min, while the temperatures at the dummy were at that time less than 80 °C. The toxicity of smoke gases was assessed using the
fractional effective dose concept. The various experimentally parameters (temperature and smoke gas composition) were implemented into numerical simulations with fire dynamics simulator. Both the experimental data and the numerical simulations are presented and discussed.