(142b) Analysis of Dust Concentration Measurements Taken during the Filling Process of a Silo

The consequence of the release of fine particles smaller than 500 microns than can form dust clouds in the handling and storing equipment can be severe. These dust clouds present potential dust explosion hazards because the airborne dust can occur in concentrations within the dust explosion limits of the material, during the filling process of storage silos. In terms of safety, a considerable number of factory workers have lost their lives throughout the years due to serious accidents such as; 2003 explosion at West Pharmaceutical Services in Kinston, North Carolina (6 casualties), the 2008 explosion at Imperial Sugar Plant in Savannah, Georgia (killing 14), and the 2009 explosion in a coal silo at WE Industries power plant in Oak Creek, Wisconsin (injuring 7) (Davis et al., 2011). Hence, dust explosions become a major concern of industries (e.g. power, chemical, pharmaceutical or food industries) handling organic products, grain and flour, metal products or pulverised coal to mention just a few. Preventing dust explosions and the damage of plant infrastructures require a profound understanding of the particle/ air dynamics in the dust cloud circulating in the storage silo.

This research aims to construct a model which predicts the spatial distribution of dust concentrations during the filling process of a silo. Then passive explosions protection systems such as panels on the silo roof ventilations can be effectively designed to prevent explosions. The dust distribution was measured with an optical method developed by (Lulbadda Waduge et al., 2016). The optical method employed in a small scale experimental rig which is essentially a fluidised bed with fine materials and a single camera together with a laser source were utilised to capture the dust concentration in different areas when the dust is airborne. Then images of repeated runs were taken and post processed to compare different dust concentration levels in each set.

The hydrodynamics of the process supposed to behave the same at each repeated run of the experiment as experiments were identical to each other regarding materials and the scale. Having the same ranges of concentrations distribution at each repeated test were obtained.

L.L. Lulbadda Waduge, S. Zigan, L.E. Stone, A. Belaidi, P. García-Triñanes, Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations, Process Safety and Environmental Protection, Volume 105, 2017, Pages 262-273, ISSN 0957-5820, http://dx.doi.org/10.1016/j.psep.2016.11.013.

(http://www.sciencedirect.com/science/article/pii/S095758201630283X)

Keywords: Laser; Optical method; Dust explosions; CFD; Experimental; Storage silos; Particle dynamics