When propane cylinders are exposed to a fire, and safety devices like pressure relief valves fail, after a short time the failure of the cylinder with a subsequent explosion of the gas air mixture involving blast, fragments, hot gases and intensive infrared radiation may occur. These consequences of a cylinder failure are a high risk for users, rescue forces and the surrounding infrastructure.
The presented bonfire tests of 15 identical gas vessels (commercial, off-the-shelf cylinder filled with 11 kg of liquid propane, without safety device) deliver a stable basis for studying the resulting consequences of cylinder failure. Three different types of fire for the heat transfer into the cylinders were used: wood fire, gasoline pool fire, propane gas fire. All tested cylinders failed within a period of 70 s to 152 s after ignition and fragmented into up to seven major parts (average: four objects) covering distances of up to 262 m.
In all tests, the liquid phase temperature inside the cylinder, the cylinder wall temperature (top, side, bottom) and the temperature of the surrounding fire (top, side, bottom) were measured. Furthermore, the inner cylinder pressure and the induced overpressure of the blast wave after the failure were recorded. Overpressures of up to p = 0.27 bar were measured in a distance of l = 5 m. Each test was documented by video from several positions: close-up, general view, high-speed with 5000 frames per second.
The dataset gained within this test series enables an estimation of the potential damage to persons, infrastructure and the environment. It can also be used to increase the safety of firefighters and other forces responding to fires involving gas cylinders. The currently available standard tactics, the recommended safety distances and the properties of the personal protective equipment can be adjusted regarding this analysis.
Mobile gas cylinders in fire: Consequences in case of failure
Rico Tschirschwitz, Daniel Krentel, Martin Kluge, Enis Askar, Abdel Karim Habib, Harald Kohlhoff, Patrick P. Neumann, Sven-Uwe Storm, Michael Rudolph, André Schoppa, Mariusz Sczepaniak
Fire Safety Journal, Volume 91, July 2017, Pages 989-996
BAM Department Chemical Safety Engineering, Division Gases, Gas Plants and Division Reactive Substances and Systems and Division Constructive Fire and Explosion Safety for Gases; Department Containment Systems for Dangerous Goods, Division Tanks for Dangerous Goods and Accident Mechanics; Department Non-Destructive Testing, Division Sensors, Measurement and Testing Methods