Investigating the effect of random packing on flame quenching and explosion pressure suppression

Gas-phase oxidation processes are crucial chemical reaction processes widely utilized in the production of various raw materials, intermediates, and products in several industries. Due to the fact that the raw materials in these reactions primarily consist of flammable gases, the presence of a certain concentration of oxygen in the reactant leads to the formation of a combustible system. In such cases, ignition sources can cause explosions, posing serious safety risks to personnel and equipment. In this study, the use of porous inert random packing to quench propylene-air flame was innovatively proposed, and the performance of various types of porous inert packing in extinguishing flames and reducing the maximum explosion pressure was also investigated by self-made detonation tube. The results show that the flame of 8 % C₃H₆-92 % air premixed gas can be effectively quenched within 20 cm by filling the random packing in a pipe with a diameter of 20 mm at the pressure of 110 kPa and 160 kPa. Raschig ring packing can control the flame quenching distance within 5 cm. When the initial pressure of premixed gas is 110 kPa, implementation of Dixon ring packing achieves a 13.3 % reduction in maximum explosion overpressure relative to the empty chamber configuration. In addition, the effects of hydrogen on flame quenching distance and explosion pressure rise were also performed, and the flame quenching distance and explosion are all increased compared with the system of C₃H₆-9air premixed gas. Furthermore, the random packing of Pall rings cannot quench the flame of premixed gas with hydrogen addition because of its large porosity which leads to poor wall efficiency. These experimental findings provide theoretical support and guidance for the development of new types of intrinsically safe gas-solid phase reactors and offer a strategy for conducting gas-phase oxidation reactions within the explosive limit range.