Chapter 11 – Dust Explosions

TLDR: Benintendi et al. as mentioned in this paper presented a case study dealing with the Imperial Sugar Company and provided some practical guidelines for the understanding and for the calculation of dust processing scenarios, according to the great emphasis on the machinery and the ATEX directives that have been put on this specific aspect.

Abstract: Explosive behaviour of organic and inorganic dusts is frequently underestimated and sometimes neglected in risk assessment studies. The hazards related to dust combustion is often analysed only in terms of fire scenario, whereas the effects caused by pressure waves from dust explosions are in many cases more serious. This is due to several factors: the cultural growth of dust explosion phenomena has not been the same for the various application fields. Some industrial sectors, such as pharmaceutical, fine chemistry and, to a lesser extent, food industry, have developed an internal expertise and awareness about this hazard, as well as about the procedures and the technicalities to put in place in order to properly deal with the associated risk. The oil and gas and petrochemical industry is generally less aware, and worried about the explosion risk related to the processing of coke and sulphur dusts, as well as from many organic and metallic dusts included in the process cycle; the overwhelming case history of incidents caused by liquid and gaseous hydrocarbons and organic chemicals has maybe created a much stronger focus on this aspect. On the other hand, dust explosions are highly non-ideal, and possibly much less intuitive phenomena, than the corresponding gas scenarios. Moreover, equipment characteristics and configuration affect the dust behaviour and the explosive outcome much more than gas scenario. In this respect, the implementation of the European ATEX directives and the characterisation of process and plant scenarios potentially resulting in dusts explosions have contributed to increase knowledge and awareness about this subject. This chapter includes some aspects collected from the research project headed by the author (Benintendi, 2004), and aims at providing some practical guidelines hopefully useful for the understanding and for the calculation of dust processing scenarios. Some HAZID cases relating to dust processing equipment have been included, according to the great emphasis on the machinery and the ATEX directives that have been put on this specific aspect: not much guidance has been provided about this risk segment by the huge and often excellent literature on dust explosions. A case study dealing with the Imperial Sugar Company has been analysed and verified against some calculation findings.