Miller Magazine Issue: 155 November 2022

90 MILLER / NOVEMBER 2022 It is critical that all the systems and components used as a part of an explosion protection system should be third party ATEX approved. Explosion protection and prevention systems are life critical systems thus should be designed by system supplier’s qualified design engi- neers as well as should be maintained only by manufacturer approved service personnel. Mitigation of dust explosion risks at feed and grain handling operations Emre Ergun IEP Technologies Türkiye GM Dust explosions are one of the lesser-known industrial accidents when considering industrial explosions. Ignitabil- ity and explosibility parameters of grain and cereal dusts are sometimes not well understood by the operators of such plants. However, dust explosions often occur in the grain handling facilities due to large amounts of combus- tible dust formed during operations. In general, if a solid material is combustible, then in its dust form (particle size < 500 microns), it can become explosible if certain conditions are met. In the feed and grain industry, most of the materi- al used throughout the processes are combustible organic material. Thus, use of explosion and prevention methods would help to minimize such risks while providing a safer work environment. What is a dust explosion? For a dust explosion to occur, five elements should be present simultaneously: 1) enough amount of combustible dust (particle size < 500 micron), 2) Suspension of the dust in air creating a dense dust cloud, 3) Confined space (pro- cess vessels and/or closed buildings), 4) Ignition source sufficient to ignite the dust cloud, 5) Oxygen source (such as air). When all five of these elements are present, then a dust explosion would occur. In many cases, explosion starts inside a process equipment, then quickly propagates to interconnected vessels or to production floor via con- necting pipes, or process openings, creating a Secondary Explosion. Secondary explosions are known to be much more destructive to overall production plant. System own- Picture 1 – Consequence of a grain silo dust explosion ARTICLE