RR1209: Investigation of Mist Explosion Hazards (MIST2) - Nozzle Shape Effects Using SLM
Many types of industrial equipment can potentially produce an explosive oil mist if a fault develops. This includes almost all equipment where oil is under pressure, such as hydraulic systems, pressurised lubrication, oil-based heat transfer systems among others. These are in widespread use and appear in areas such as service plant rooms and production facilities in many industries. As part of controlling the risk of oil mist explosions, the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) require risk based 'area classification' in places where oil mists can be produced. However, information on the conditions in which an oil mist can be ignited and continue to burn is limited.
A previous programme of work, called MISTS (summarised in RR1107), had shown that kerosene jet fuel mists were readily ignited, even during very low pressure leaks. That finding had been unexpected, as it had previously be assumed that releases driven by pressures below 5 barg to 10 barg were unlikely to contain enough of the small droplets that are needed for the mist to be ignitable.
This report presents experimental work carried out by Cardiff University researchers working at the Gas Turbine Research Centre in Port Talbot. This work was one work package in a larger programme about oil mist risks called MISTS2. The overall MISTS2 project is summarised in a separate report (RR1207).
The MISTS2 project focused on situations where empirical results could be used to give the greatest improvement in understanding of mist explosion safety.
This report and the work it describes were funded by the Health and Safety Executive. Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
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