Process Area Activity – [I See Now-23]: High-speed flowing air is the ignition source

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Once, after the vacuum distillation vessel was vented at the end of a process, it was soon found that the temperature at the top of the tower rose sharply, increasing from 165 degrees to 250 degrees within half an hour. The tower caught fire, and steam was immediately injected using steam lift pipes to extinguish the fire. Upon checking the system later, it was found that the operator did not follow the operating procedures after starting the venting process. (At the beginning of venting, both the distillation tank and the receiving tank were vented at the same time; once venting had begun, it was necessary to close either the vent valve on the distillation tank or that on the receiving tank, in order to prevent air circulation and the rise of hot air currents.) ) Neither of the two relief valves was closed. Everyone knows the three elements of combustion: fuel, oxidizer, and an ignition source. The packing inside the tower has a certain amount of liquid retention, and this is the combustible material. When air circulates, oxygen is present, which provides a fuel for combustion. However, the employees do not know what the ignition source is; it is the static electricity or sparks generated by the friction between the rapidly flowing air and the hot metal filler (165 degrees) that serve as the ignition source. Those in the gas industry know that leaks in high-pressure hydrogen pipelines can lead to fires; the source of ignition is the static electricity generated by the friction between high-flow hydrogen and the pipeline or air.