Characteristic evaluation of aluminum dust explosion venting with high static activation pressure

Abstract

Aluminum dust explosion venting experiments with static activation pressure ranging from 70 kPa to 280 kPa were conducted in the 20 L spherical chamber with venting diameters from 20 mm to 125 mm. For the case of high activation pressure, the maximum flame length in experiments is 1.64 m, which is close to the prediction of standard, while the maximum width is significantly smaller than the prediction. New fitting formulas in a laboratory scale for flame length and width are obtained, which provide a reference for venting safety area design, and the effect of activation pressure, dust concentration and venting area are taken into account. By the comparison, the external pressure prediction of EN14491 shows a good performance and NFPA68 has an opposite trend with experiments. Based on the experimental results, it is found that the the external pressure attenuation is inversely proportional to the distance, which is different with the coefficient of the distance suggested by the standard EN 14491.