Effect of Particle Breakage on Explosibility of Coal/Rock Dust Mixtures Due to Dispersion in 20-L Chambers

摘要

Research has shown mat particle size has a significant impact on the explosibility of coal dust/rock dust mixtures. Previous explosion studies conducted using the U.S. Bureau of Mines'(BOM) 20-L explosion chamber tend to show a difference in the amount ofinerting material needed to prevent an explosion when compared to the 20-L Siwek chamber. To reconcile these differences, samples were comparatively tested in the historic BOM 20-L chamber and the new NIOSH 20-L Siwek chamber with an emphasis on particle breakage. Rock dust and coal dust samples were dispersed in the chambers without ignitors and their specific surface areas were compared to the undispersed specific surface areas in order to quantify the breakage. Then, rock dust and coal dust mixtures were prepared, dispersed using the Siwek chamber, collected and tested for explosibility in the BOM 20-L chamber to see if the severe particle breakage in the Siwek chamber would influence the inerting limits of the BOM chamber. Results indicate that the particle breakage of friable brittle materials during explosion testing should be considered when evaluating the explosion risks in the process industries.