Explosions of vapor/aerosol clouds
In deflagration, the combustion process propagates outward at speeds slower than that of sound (subsonic speeds). However, typically flame accelerates because of turbulence generation of the moving gas ahead of the flame. Flame can start at speeds as low as m/s order of magnitude and accelerates up to 600 m/s. Factors that increase turbulence are blockage ratio and congestion. Blast strength and hence damage increases with flame speed. In detonation, the speed is faster than the local speed of sound (supersonic speed), causing explosion, resulting in shattering of objects in the path. For a long time, occurrence of detonation in vapor clouds have been denied or at least doubted, but only the last few years evidence has been found that it is possible. Detonation occurs only in massive clouds under near wind still conditions.
Deflagration to Detonation
Deflagration to detonation (DDT) refers to the phenomena whereby the propagation of the combustion process of a flammable gas and air mixture suddenly transitions to an explosion. Energy is released during combustion. DDT incidents can be particularly dangerous in congested spaces such as offshore oil and gas production platforms.
Currently, MKOPSC is validating the likelihood to obtain Deflagration-to-Detonation Transition (DDT) on different scenarios by using the CFD model in FLACS. So far, the validation has been carried out with data found in the literature. Moreover, the current facilities available at the Turbomachinery Laboratory of Texas A&M University are being used to run, experiments that will provide data to help validating this CFD model.
Dust Explosion Research
Every process involving combustible finely divided solids or dusts is associated with explosion hazards. Although detailed statistical records of dust explosion are not generally available, it is known that approximately 70% of the dusts or powders processed in the chemical process industry are combustible and ignitable. Data from the Health and Safety Executive indicate one dust explosion every day in Europe, with damages from each incident in the range of millions of dollars, not including the damage and loss caused by injuries, fatalities, production stoppages, and marketing losses. In the United States, some recent incidents where dust explosions were most likely the root cause include incidents in Indiana (October 2003), Kentucky (February 2003), and North Carolina (January 2003). As stated by the U.S. Chemical Safety Board in regard to the June 18, 2003, dust explosion in Kinston, NC, there is a critical need for research to characterize the explosion behavior of dusts to make possible strategies for handling dusts safely and to minimize the possibility and severity and therefore the risk of industrial dust explosions.
Fundamental research in the field of dust explosions has been classified into dust cloud formation process, dust cloud ignition process, flame propagation in dust clouds, and blast waves generation by burning dust clouds. Preliminary results seem encouraging but there are still a lot unresolved issues that need to be investigated further. On the experimental front, large-scale tests need to be conducted on dusts that are able to mimic typical industrial explosion scenarios.
List of Center Publications
Enhancing the Understanding of Deflagration-to-Detonation Transition (DDT)
- Ahumada, C. B., Papadakis-Wood, F. I., Krishnan, P., Yuan, S., Quddus, N., Mannan, M. S., & Wang, Q. (2020). Comparison of explosion models for detonation onset estimation in large-scale unconfined vapor clouds. Journal of Loss Prevention in the Process Industries, 104165. https://doi.org/10.1016/j.jlp.2020.104165
- Rosas, C., S. Davis, D. Engel, P. Middha, K. van Wingerden and M.S. Mannan, “Deflagration to Detonation Transitions (DDTs): Predicting DDTs in Hydrocarbon Explosions,” Journal of Loss Prevention in the Process Industries, vol. 30, July 2014, pp. 263-274. Link
Dust and Aerosol Research
- Han, H., Chaudhari, P., Bagaria, P., & Mashuga, C. (2018). Novel method for hybrid gas-dust cloud ignition using a modified standard minimum ignition energy device. Journal of Loss Prevention in the Process Industries, 52, 108-112. https://doi.org/10.1016/j.jlp.2018.02.005
- Lin, Y. R., Chen, H., Mashuga, C., & Mannan, M. S. (2015). Improved electrospray design for aerosol generation and flame propagation analysis. Journal of Loss Prevention in the Process Industries, 38, 148-155. https://doi.org/10.1016/j.jlp.2015.09.011
- Bagaria, P., Zhang, J., & Mashuga, C. (2018). Effect of dust dispersion on particle breakage and size distribution in the minimum ignition energy apparatus. Journal of Loss Prevention in the Process Industries, 56, 518-523. https://doi.org/10.1016/j.jlp.2017.07.001
- Chaudhari, P., & Mashuga, C. V. (2017). Partial inerting of dust clouds using a modified standard minimum ignition energy device. Journal of Loss Prevention in the Process Industries, 48, 145-150. https://doi.org/10.1016/j.jlp.2017.04.022
- Pranav Bagaria, Jiaqi Zhang, Chad Mashuga, “Effect of Dust Dispersion on Particle Breakage and Size Distribution in the Minimum Ignition Energy Apparatus”, Journal of Loss Prevention in the Process Industries, July, 2017. https://www.sciencedirect.com/science/article/pii/S0950423017301912
- Purvali Chaudhari, Chad Mashuga, “Partial Inerting of Dust Clouds Using a Modified Standard Minimum Ignition Energy Device”, Journal of Loss Prevention in the Process Industries, Vol. 48, pp 145-150, July, 2017.https://www.sciencedirect.com/science/article/pii/S0950423017301122
- Jiaqi Zhang, Yi Liu, Hallie Elledge, Hao Chen, M. Sam Mannan, Chad V. Mashuga, “Thermal Stability and Explosibility of Carbon Nanofibers Affected by Different Processes”, Journal of Thermal Analysis and Calorimetry, pp 1-11, February, 2017.
- Pranav Bagaria, Jiaqi Zhang, Entao Yang, Ashok Dastidar, Chad Mashuga, “Effect of Dust Dispersion on Particle Integrity and Explosion Hazards”, Journal of Loss Prevention in the Process Industries, Vol. 44, pp 424-432, November, 2016.https://www.sciencedirect.com/science/article/pii/S0950423016303230
- Johnston, H.G., A.Y. Chowdhury, M.S. Mannan and E.L. Petersen, “Effect of Coal-Limestone Mixtures on Dust Dispersion Behind a Moving Shock Wave,” Journal of Loss Prevention in the Process Industries, vol. 44, November 2016, pp. 551-563. https://www.sciencedirect.com/science/article/pii/S0950423016301814
- Chowdhury, A.Y., B.D. Marks, H.G. Johnston, M.S. Mannan and E.L. Petersen, “A New Facility for Studying Shock-Wave Passage Over Dust Layers,” Shock Waves, vol. 26, no. 2, March 2016, pp. 129-140. https://link.springer.com/article/10.1007/s00193-015-0586-z
- Chowdhury, A.Y., H.G. Johnston, B. Marks, M.S. Mannan and E.L. Petersen, “Effect of Shock Strength on Dust Entrainment Behind a Moving ShockWave,” Journal of Loss Prevention in the Process Industries, vol. 36, July 2015, pp. 203-213. https://www.sciencedirect.com/science/article/pii/S0950423015000583
- Ramírez-Marengo, C., C. Diaz-Ovalle, R. Vázquez-Román and M.S. Mannan, “A Stochastic Approach for Risk Analysis in Vapor Cloud Explosion,” Journal of Loss Prevention in the Process Industries, vol. 35, May 2015, pp. 249-256.https://www.sciencedirect.com/science/article/pii/S0950423014001491
- Zhang, J., H. Chen, Y. Liu, H. Elledge*, C.V. Mashuga, and M.S. Mannan, “Dust Explosion of Carbon Nanofibers Promoted by Iron Nanoparticles,” Industrial & Engineering Chemistry Research, vol. 54, no. 15, 2015, pp. 3989–3995. https://pubs.acs.org/doi/abs/10.1021/acs.iecr.5b00341
- Rosas, C., S. Davis, D. Engel, P. Middha, K. van Wingerden and M.S. Mannan, “Deflagration to Detonation Transitions (DDTs): Predicting DDTs in Hydrocarbon Explosions,” Journal of Loss Prevention in the Process Industries, vol. 30, July 2014, pp. 263-274. https://www.sciencedirect.com/science/article/pii/S0950423014000412
- Castellanos, D., A. Lewandowski, A. Diaz, A.F. Mejia, V. Carreto, C.V. Mashuga, A.S. Rangwala, Z. Cheng, and M.S. Mannan, “Influence of Particle Size and Crystalline Level on the Efficiency of Dust Explosion Inhibitors,” Industrial and Engineering Chemistry Research, vol. 53, no. 28, 2014, pp. 11527–11537. https://pubs.acs.org/doi/abs/10.1021/ie500671m
- Castellanos, D., V.H. Carreto-Vazquez, C.V. Mashuga, R. Trottier, A. Mejia, and M.S. Mannan, “The Effect of Particle Size Polydispersity on the Explosibility Characteristics of Aluminum Dust,” Powder Technology, vol. 254, March 2014, pp. 331–337. https://www.sciencedirect.com/science/article/pii/S0032591013007110
- Castellanos, D., T. Skjold, K. van Wingerden, R.K. Eckhoff, and M.S. Mannan, “Validation of the DESC Code in Simulating the Effect of Vent Ducts on Dust Explosions,” Industrial and Engineering Chemistry Research, vol. 52, no. 17, 2013, pp. 6057–6067. https://pubs.acs.org/doi/abs/10.1021/ie4004943