Inerting of coal dust explosions in laboratory- and intermediate-scale chambers

Experiments were performed to compare intermediate-scale (1 m3) and laboratory-scale (20 l) coal dust inerting results. Intermediate-scale inerting levels appear to be lower than laboratory-scale values. This can possibly be attributed to the use of a strong ignition source to initiate the test, which may have overdriven the explosions in the smaller test vessel. Previously reported agreement between the smaller test vessel and full-scale experiments may be due to overdriving in the 20 l chamber, leading to high inerting levels similar to those encountered in full-scale tests due to flame acceleration. Additionally, a reduction in the particle size of the rock dust used for inerting has been found to influence the quantity required to prevent an explosion in the 1 m3 chamber. This agrees with previous work conducted in smaller chambers.