AN INHERENTLY SAFER APPROACH FOR NONTRADITIONAL DUST EXPLOSION RISK REDUCTION

Abstract

Dust explosions continue to occur in industrial processes that handle combustible powders. Considerable research is therefore conducted with the objectives of both preventing the occurrence and mitigating the consequences of such events. But, most of the research conducted in relation to dust explosion is based on traditional fuel/air system (e.g., micron-sized powder, spherical shape powder and fuel with single component). Due to the increased demand, nanotechnology and its applications; textile industries and other flock manufacturing plants; and pharmaceutical industries are growing rapidly day by day. Such industries can generate severe risk of explosions associated with nontraditional dusts (the term ‘nontraditional’ has been used in the current study as: (i) nano-sized powder rather than micron-sized (e.g., nano-sized Ti powder); (ii) flocculent materials characterized by a length-to-diameter ratio rather than a particle diameter (e.g., polyamide 6.6 and polyester fibers); and (iii) hybrid mixtures consisting of a combustible dust and a flammable gas or solvents rather than single component (e.g., lactose admixed with methanol)). A generalized Quantitative Risk Management Framework (QRMF) for dust explosions has been applied in the current work to integrate the above three nontraditional categories of dust explosions. Experimental results have been used as input to the quantitative risk management framework so as to provide a comprehensive procedure to analyze, assess, and control the likelihood and consequences of explosions associated with nontraditional dusts. Risk management strategies have been developed through a synthesis of experimental findings and a comprehensive literature review. Use of the QRMF for the three nontraditional fuel/air systems has been ensured with each system being considered from the key perspectives of hazard characterization, hazard identification, risk assessment, and risk control (along with other aspects of the quantitative risk management sequence). Explosion prevention and mitigation measures have been taken in an inherently safer approach which start with inherent safety measures at beginning, then passive and active engineered devices, and procedural measures in an hierarchical manner. The findings of this research can facilitate industrial facilities in Canada and worldwide with safer operations by preventing and mitigating explosions associated with the aforementioned nontraditional dusts.