Incendive sparks originating from charged water mists

It was in January 1970 that a coordinated research program was set up by Shell to investigate the hazards involved in tank washing of VLCC. The work has been undertaken principally at Koninklijke/ Shell Laboratorium, Amsterdam (K. S. L. A.), the Shell Thornton Research Centre and at Southampton University. The purpose of this paper is to give an account of some ignition experiments carried out at Southampton, during which it was demonstrated that propane/air mixtures can be ignited by an unusual mechanism involving circumstances which could be realized during tank washing with high velocity water jets.