Effect of ignition on the explosion behavior of 1-Octadecanol/air mixtures

Maximum explosion overpressure and deflagration index determined in dust explosions must comply with the specifications of current testing standards. In previous study, experiments performed in different volume vessels using different igniters resulted in different test results, although the test conditions were the same. In addition to the effects of scaling, the effects of igniters must also be accounted for in the data interpretation of dust explosions. In this paper, the effects of igniters including the effects of ignition energy and types on overpressure behaviors during 1-Octadecanol dust explosions are examined in the 20 L standard test system. It was observed that igniters strongly affected explosion overpressure behaviors during dust explosions. As the ignition energy increased from 2.5 kJ to 10 kJ, the apparent maximum explosion pressure and deflagration index significantly increased. And pressure increased earlier and reached a higher value as chemical igniters were used to ignite the dust cloud. Detailed analysis was conducted on the igniting mechanism of different igniters and energy loss of the electrostatic igniters in the capacitor discharge process was measured by the spark discharge circuit test system. Furthermore, time scales were analyzed to explain the discrepancies of the maximum explosion pressure and deflagration index for different igniters.