| Dispersion tests were carried out in the Siwek 20-L chamber to investigate its dust dispersion efficiency, using three dusts namely, gilsonite, purple K and Pittsburgh coal dust. During these tests, a United States Bureau of Mines (USBM) optical dust probe that operates on the principle of attenuation of light was used to measure the transmissions at different locations within the chamber volume. The tests were repeated thrice for each dust at five different nominal dust concentrations and six probe locations, with the two standard nozzles of the chamber, namely, the rebound nozzle and the perforated annular nozzle. A total of 540 dispersion tests were performed and the transmissions corresponding to the ignition delay period of the chamber were used to (a) determine the variations in spatial uniformity of dispersion obtained with both dispersion nozzles; (b) make comparisons between the experimental transmission data and the transmissions calculated from the theoretical relationship (Beer's law); and (c) make comparisons between the transmission data obtained from other frequently used test vessels in dust explosibility studies, namely, the USBM 20-L and Fike 1-m3 chambers. (Abstract shortened by UMI.)... |
