Particle segregation in a fluidized bed

Abstract

AbstractParticle segregation data at low gas velocity, near the minimum fluidizing velocity, are presented for particles of different size (150 to 2800 μm) and density (720 to 2800 kg/m3) in a fluidized bed. Phase diagrams similar to those of liquid‐solid systems are developed to present the results. The data were collected in a 100 mm diameter unit operating at pressures up to 660 kPa and a 114 mm diameter unit at atmospheric pressure.The particle segregation data were obtained to provide design and operating criteria for a two‐stage. i.e., an agglomerating combustor/gasifier and a devolatilizer/desulfurizer, fluidized bed coal gasification process to produce low heating‐value gas (890‐1350 K‐cal/m3) for power generation. The data indicate that the criteria for particle separation can be achieved if the operating gas velocity is close to the minimum fluidizing velocity of the dense particles, that is, agglomerated ash, and spent dolomite.