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Numerical simulation of the effect of diaphragm orifice diameter in a flameproof enclosure with an interconnected structure during pressure piling

Combustible gas explosions are typically triggered at high temperatures by the generation of electric sparks on starting, stopping, or short circuiting of electrical equipment. Flameproof enclosures are widely installed in the petrochemical industry as safety equipment for eliminating ignition sources. Such enclosures are designed with a double-cavity structure, and a hole plate is used to connect the two cavities. However, pressure piling occurs in such double-cavity-connected structures, resulting in flameproof enclosures requiring to bear higher pressure than designed, which is a safety hazard. However, few studies have focused on the effect of the diaphragm orifice diameter of flameproof enclosures. Because the explosion of combustible gas in a flameproof enclosure is a complex process, numerical simulation was performed to study the process. Fluent was used for numerically simulating the ethylene/air premixed gas explosion characteristics of double-cavity-connected structure flameproof enclosures. The effects of an orifice hole diameter from 10 to 45 mm on flameproof characteristics, including the maximum explosion pressure, maximum explosion pressure rise rate, and maximum explosion index, were examined. The results are critical for the effective design of a double-cavity flameproof shell and provide theoretical support for fire suppression in a flameproof enclosure.
PAPER REVISED: 2022-08-15
PAPER ACCEPTED: 2022-08-19
  1. Explosive atmospheres - Part 1: Equipment protection by flameproof enclosures "d". 2018, International Electrotechnical Commision: Geneva, Switzerland.
  2. International Electrotechnical Vocabulary(IEV)-Part 426:Explosive Atmospheres. 2020, International Electrotechnical Commission: Geneva, Switzerland.
  3. Benedetto, A.D., et al., The mitigation of pressure piling by divergent connections, Process Safety Progress, 24. (2010), 4, pp. 310-315
  4. Razus, D., et al., Transmission of an explosion between linked vessels, Fire Safety Journal, 38. (2003), 2, pp. 147-163
  5. Zhang, J., et al., Experimental study on explosion pressure testing for cylindrical flameproof products, Journal of Safety Science and Technology. (2019),
  6. Zhe, J.U., et al., The Superposition Impact of Orifice Structure of Flameproof Enclosure on Explosion Pressure, Safety in Coal Mines. (2014),
  7. Bartknecht,Wolfgang, Dust Explosions Course, Prevention, Protection. Dust Explosions Course, Prevention, Protection /, 1981.
  8. Razus, D., et al., Transmission of an explosion through a narrow channel, Rivista dei Combustibili, 51. (1997), 3, pp. 126-136
  9. Zhen, et al., Experimental study of the initial pressure effect on methane-air explosions in linked vessels, Process Safety Progress. (2018),
  10. Ogungbemide, D., et al., Numerical modelling of the effects of vessel length-to-diameter ratio (L/D) on pressure piling, Journal of Loss Prevention in the Process Industries, 70. (2021), 1-2, p. 104398
  11. Ogungbemide, D.I., A CFD study of the effects of pipe bending angle on pressure piling in coal dust explosions in interconnected vessels. (2022),
  12. Kumar, et al., Dynamic response and effect of apertures on explosion parameters of flameproof apparatus, Journal of Loss Prevention in the Process Industries. (2015),
  13. Krause, T., et al., Investigations of static and dynamic stresses of flameproof enclosures, Journal of Loss Prevention in the Process Industries, 49. (2017),
  14. Munro, J., et al., Flame Transmission at Extremely Low Temperatures when Pressure Piling is Present, IEEE Transactions on Industry Applications, PP. (2016), 99, pp. 1-1
  15. Chen, F., Effect of Termination Compartment on Explosion Pressure of Flameproof Motor, Safety in Coal Mines, 50. (2019), pp. 129-131
  16. A, F.C., et al., Experimental analysis of gas explosions at non-atmospheric initial conditions in cylindrical vessel, Process Safety and Environmental Protection, 88. (2010), 5, pp. 341-349
  17. Singh, J., Gas explosions in inter-connected vessels: Pressure piling, process safety & environmental protection. (1994),
  18. Kurdyumov, V.N.,M. Matalon, Flame acceleration in long narrow open channels, Proceedings of the Combustion Institute, 34. (2013), 1, pp. 865-872
  19. Kurydumov, V.N.,M. Matalon, Self-accelerating flames in long narrow open channels, Proceedings of the Combustion Institute, 35. (2015), 1, pp. 921-928
  20. A, R.H., et al., Effects of position and frequency of obstacles on turbulent premixed propagating flames, Combustion and Flame, 156. (2009), 2, pp. 439-446
  21. Rogstadkjernet, L., Combustion of Gas in Closed, Interconnected Vessels: Pressure Piling, University of Bergen. (2004),
  22. Yu, M., et al., Effect of obstacles on explosion characteristics of methane/hydrogen, Explosion and Shock Waves. (2018),
  23. Benedetto, A.D.,E. Salzano, CFD simulation of pressure piling, Journal of Loss Prevention in the Process Industries, 23. (2010), 4, pp. 498-506
  24. Li Run-zhi., et al., Influence of environmental temperature on gas explosion pressure and its rise rate, Explosion and Shock Waves, 33. (2013), 4, pp. 415-419