Steam explosion

Tanks containing [[Petroleum|crude oil]] and certain commercial oil cuts, such as some [[Diesel fuel|diesel oils]] and [[kerosene]], may be subject to [[boilover]], an extremely hazardous situation in which a water layer under an open-top tank pool fire starts boiling, which results in a significant increase in fire intensity accompanied by violent expulsion of burning fluid to the surrounding areas. In many cases, the underlying water layer is [[Superheated water|superheated]], in which case part of it goes through explosive boiling. When this happens, the abruptness of the expansion further enhances the expulsion of blazing fuel.{{sfnp|Ferrero|2006|p=6}}{{Cite magazine |last=Garrison |first=William W. |year=1984 |title=C.A. La Electricidad de Caracas, December 19, 1982, Fire (Near) Caracas, Venezuela |url=https://www.icheme.org/media/5781/lpb_issue057p026.pdf |archive-url=https://web.archive.org/web/20230722153934/https://www.icheme.org/media/5781/lpb_issue057p026.pdf |archive-date=22 July 2023 |access-date=22 July 2023 |journal=[[Loss Prevention Bulletin]] |publisher=[[Institution of Chemical Engineers|Institution of Chemical Engineers (IChemE)]] |pages=26–30 |issue=57 |issn=0260-9576}}{{Cite journal |last1=Broeckmann |first1=Bernd |last2=Schecker |first2=Hans-Georg |date=1995 |title=Heat Transfer Mechanisms and Boilover in Burning Oil–Water Systems |journal=[[Journal of Loss Prevention in the Process Industries]] |volume=8 |issue=3 |pages=137–147 |doi=10.1016/0950-4230(95)00016-T |bibcode=1995JLPPI...8..137B |issn=0950-4230 |eissn=1873-3352}}

Tanks containing [[Petroleum|crude oil]] and certain commercial oil cuts, such as some [[Diesel fuel|diesel oils]] and [[kerosene]], may be subject to [[boilover]], an extremely hazardous situation in which a water layer under an open-top tank pool fire starts boiling, which results in a significant increase in fire intensity accompanied by violent expulsion of burning fluid to the surrounding areas. In many cases, the underlying water layer is [[Superheated water|superheated]], in which case part of it goes through explosive boiling. When this happens, the abruptness of the expansion further enhances the expulsion of blazing fuel.{{sfnp|Ferrero|2006|p=6}}{{Cite magazine |last=Garrison |first=William W. |year=1984 |title=C.A. La Electricidad de Caracas, December 19, 1982, Fire (Near) Caracas, Venezuela |url=https://www.icheme.org/media/5781/lpb_issue057p026.pdf |archive-url=https://web.archive.org/web/20230722153934/https://www.icheme.org/media/5781/lpb_issue057p026.pdf |archive-date=22 July 2023 |access-date=22 July 2023 |journal=[[Loss Prevention Bulletin]] |publisher=[[Institution of Chemical Engineers|Institution of Chemical Engineers (IChemE)]] |pages=26–30 |issue=57 |issn=0260-9576}}{{Cite journal |last1=Broeckmann |first1=Bernd |last2=Schecker |first2=Hans-Georg |date=1995 |title=Heat Transfer Mechanisms and Boilover in Burning Oil–Water Systems |journal=[[Journal of Loss Prevention in the Process Industries]] |volume=8 |issue=3 |pages=137–147 |doi=10.1016/0950-4230(95)00016-T |bibcode=1995JLPPI...8..137B |issn=0950-4230 |eissn=1873-3352}}

'''Boil''' '''over'''

'''Boil''' '''over overview'''

Although the general concept of boil over is known, it is essential to understand the particularities of heat transfer involved to ensure proper safety engineering. According to Broeckmann and Schecker 1995, the phenomenon does not merely consist in a phase change. The boil over process entails a heat layer penetrating the fuel layer progressively from above due to distillation phenomena. Once it comes into contact with the layer of water below, an explosive flash can take place.{{Cite journal |last=Broeckmann |first=Bernd |last2=Schecker |first2=Hans-Georg |date=1995-01-01 |title=Heat transfer mechanisms and boilover in burning oil-water systems |url=https://www.sciencedirect.com/science/article/pii/095042309500016T |journal=Journal of Loss Prevention in the Process Industries |volume=8 |issue=3 |pages=137–147 |doi=10.1016/0950-4230(95)00016-T |issn=0950-4230}} This is amplified by the viscosity of the oil, which hinders the growth of steam bubbles. As a result, the pressure inside the system steadily rises, leading to a sudden release of accumulated energy. Another finding that the authors present is that the explosiveness of the event is positively related to the degree of "superheating" of the water layer. In other words, the temperature in the layer of water could be elevated to a significantly higher temperature than that of ordinary boiling water, thus resulting in even more catastrophic consequences than in conventional steam boiler explosions.

Although the general concept of boil over is known, it is essential to understand the particularities of heat transfer involved to ensure proper safety engineering. According to Broeckmann and Schecker 1995, the phenomenon does not merely consist in a phase change. The boil over process entails a heat layer penetrating the fuel layer progressively from above due to distillation phenomena. Once it comes into contact with the layer of water below, an explosive flash can take place.{{Cite journal |last=Broeckmann |first=Bernd |last2=Schecker |first2=Hans-Georg |date=1995-01-01 |title=Heat transfer mechanisms and boilover in burning oil-water systems |url=https://www.sciencedirect.com/science/article/pii/095042309500016T |journal=Journal of Loss Prevention in the Process Industries |volume=8 |issue=3 |pages=137–147 |doi=10.1016/0950-4230(95)00016-T |issn=0950-4230}} This is amplified by the viscosity of the oil, which hinders the growth of steam bubbles. As a result, the pressure inside the system steadily rises, leading to a sudden release of accumulated energy. Another finding that the authors present is that the explosiveness of the event is positively related to the degree of "superheating" of the water layer. In other words, the temperature in the layer of water could be elevated to a significantly higher temperature than that of ordinary boiling water, thus resulting in even more catastrophic consequences than in conventional steam boiler explosions.