Dust generation from powders: A characterization test based on stirred fluidization

• Develop an innovative test to characterize the dustiness of powders
• Compare the efficiency of the new test and a conventional test
• Perform a parametric study to optimize the performance of the test
• Stirred fluidization allows accurate characterization of total dust within ± 5%.

The aim of this paper was to develop an experimental test based on combination of fluidization and stirring in the perspective of its use for dustiness assessment. A parametric study on various factors that influence the release of fine particles (considered as dust) from a fluidized bed of binary mixtures of coarse and fine particles is presented. The emission of fine particles is found to be lower when the density of fine particles is high, and when the fluidization gas velocity, the mean size and the relative amount of fine particles in the mixture are low. Different binary mixtures with various fine/coarse fractions were tested in a classical fluidized bed as well as in a stirred fluidized bed. The experiments show that the total recovery of fine particles obtained by the combined test exceeds 80% whereas for the same aeration conditions and test duration, the classical fluidized bed releases only about 20% of the total mass.

Dust recovery using a fluidization test with and without stirring from a binary mixture of coarse (97% w/w ZrSiO4, 210 μm) and fine (dust) (3% w/w ZrSiO4, 30 μm) particles. Fluidization velocity = 0.13 m s− 1.Figure optionsDownload as PowerPoint slide