The cooperative mechanism in the ignition of dust dispersions

Corrections to facilitate planar imaging of particle concentration in particle-laden flows using Mie scattering Part 2: Diverging laser sheets

“…7 and a density of approximately 700 kg͞m 3 . A Malvern particle sizer was used to characterize the diameters of the particle sample.…”

“…It is difficult to measure particle numbers accurately under these conditions, since the size distribution is wide and total numbers are very sensitive to the large numbers of very fine particles ͑Ͻ1 m͒. Nevertheless, by way of illustration, a typical coal of density 1300 kg͞m 3 and a mass loading ratio of 10 would have more than 2 ϫ 10 12 particles per cubic meter, were all particles to be 10 m in diameter. It should be noted that this mass loading typically represents the upper end of number density in combustion systems, since many systems would operate with somewhat lower mass loadings, and also the particles disperse as they move from the conveying system into, and through, the flame.…”

“…Knowledge of the instantaneous distribution and number density of coal particles as they disperse into a combustion chamber is important in the optimization of such systems. In the combustion of coal, for example, the instantaneous concentration has a direct influence to the ignition location, temperature, and emission production [3]. Public awareness of the detrimental effects of combustion emissions and government policies are driving the further optimization of coal combustion [4], and the use of replacement fuels, such as biomass and waste fuels [5].…”

Theoretical Approach to Dust Explosion

“…The number of the particles n in the dust cloud with a diameter land the dust concentration Cd is n = CdP !PsD/ (2) for the particle of a density Ps· The generated heat G in the lump of the particles and the emitted heat U from them are calculated in the following equations: stant and film coefficient of heat transfer, respectively. The suffixes P, G and W represent particle, gas and wall respectively.…”

Thermally induced structural changes in coal combustion. Final report

“…Coal char particles were made from PSOC 1451 bituminous coal by Sahu et al 10 Briefly, the chars were made as follows: PSOC 1451 coal was ground and sieved. Coal particles in the 104 to 125 µm fraction were entrained in a stream of nitrogen and passed through a drop tube furnace to a temperature of 1200 or 1600K for two seconds.…”