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The application of oxygen consumption calorimetry to determine the flammability of chloroprene conve |
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The application of oxygen consumption calorimetry to determine the flammability of chloroprene conveyor belts Author: J. Wachowicz
Conveyor belts, as currently in coal mines, present a considerable fire risk, and therefore an important consideration is that these they should be fire resistanton. The paper presents a new methodology of investigation of conveyor belt flammability, worked out on the basis of the oxygen consumption calorimetry method, using Thornton's rule (according to which the heat released during the combustion of the organic materials ? per specific mass of oxygen consumed ? is constant). By this means it is possible to calculate the heat released during combustion of the conveyor belt located in the full-scale fire-testing gallery, using the formula (12). The heat released during the combustion of conveyor belts located in a fire-testing gallery depends on the length of the conveyor belt being burned (Fig. 3). The total heat released (THR) and the average effective heat of combustion (HOCav) (Table 1) determined by means of the cone calorimeter method further allows for the determination of the heat released during the fire in the fire-testing gallery. The heat released during the fire of the conveyor belt calculated using the above methodology demonstrates the correlation with the length of the conveyor belt burned in the fire-testing gallery (Figs. 4 and 5). The correlation demonstrated leads to the development of a methodology allowing the length of the conveyor belt which would be burned during the fire in the fire-testing gallery to be predicted on the basis of the results of the cone calorimeter test (Figs. 6 and 7; formula 14 and 15). The critical temperature of the belt's surface (formulas 16-20) ? representing the belt's surface temperature during ignition ? may be determined based on the time of sustained ignition obtained using the cone calorimeter method. It is the correlation binding the critical temperature of the belt's surface with the length of the belt burned in the fire-testing gallery (Fig. 8) that allows for the determination of the limit value (Tig,cr = 264°C) which further establishes the criterion for fulfilling currently applicable fire safety regulations for the full-scale gallery test.
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2011