Particle Bulk Density Research Articles

Extinction coefficient measurement of ambient aerosol particles using a ‘white cell’

It was possible to demonstrate in field experiments, that a ‘White Cell’ is a suitable instrument for ambient aerosol extinction measurements even under conditions of low mass concentration. Unsatisfactory agreement of measured and calculated extinction coefficients is due to insufficient information on particle bulk density. The margin within which the real and imaginary parts of the complex refractive index can be varied is sufficient to achieve agreement of measurement and calculation. Future measurements will include the explicit determination of the absorption and scattering coefficients. The additional absorption measurements will help to localize the limits of possible complex refractive index variations.

高炉モデルヘの水素と水蒸気が関与する反応と層頂ガス温度の適用

The over-all reaction rate Eq. (8) of the reaction between cokes and steam is derived, considering the steps of the diffusion through a gaseous film, intraparticle diffusion and chemical reaction. Considering that the rate of reaction between CO and steam is very fast and that gas flow is almost completely turbulent in the blast furnace, it has been assumed that the equilibrium of this reaction holds in the gas phase in the blast furnace. The over-all reduction rate of the iron oxide with hydrogen is given as Eq. (6), neglecting the effect of adsorption of water vapor.Our model(3) reported already has been modified here by addition of three reactions mentioned above and the boundary conditions of our new model have been calculated by means of the over-all heat and material balances and operating conditions.Using this improved model, the axial distributions of temperatures of gas and particles, volume rate of flow of gas, compositions of CO, CO2 and H2, fractional conversions of iron and of limestone, density of gas, bulk density of particles and gaseous pressure under practical operating conditions in the blast furnaces have been determined numerically by a disital computer. The calculated results are illustrated in Figs. 4 and 5.It has been confirmed that the calculated results agree well with the values reported by Shürmann(18).