MEASUREMENT OF INCIPIENT FLUIDISATION VELOCITIES IN A BED OF COARSE DOLOMITE AT TEMPERATURE AND PRESSURE.

Experiments performed with dolomite particles of a size distribution in the range of about 1410-88 mu m in a 15. 2 cm-diameter fluidised-bed reactor are described. The bed voidage at fluidisation, the mean sphericity of the solid particles, and the minimum fluidising air velocities were determined as a function of temperature (291-700 K) and pressure (179-834 kPa). The experimental data suggest that at a given temperature, the minimum fluidisation velocity decreases with increasing pressure and that at a given pressure, it is almost independent of temperature. These data were correlated using the Ergun correlation. Other correlations often employed for predicting the minimum fluidisation velocity of a bed of single size spherical particles are examined with appropriate modifications for their applicability for calculating minimum fluidisation velocities.