关键词: 流化床, 提升管, 耦合反应器, 沥青颗粒, 截面平均密度, 流动特性

Abstract: A large scale cold model device of a fluidized bed-riser coupled reactor was established according to the gasification technique for heavy oil residuum (asphalt particles). The axial distributions of the averaged cross-sectional density in the reactor were measured. The results show that the suitable operating conditions are to control the riser superficial gas velocity from 0.70 to 1.76 m/s. The behaviors of asphalt particles in the fluidized bed-riser coupled reactor present fairly different characteristics from those of the Geldart A particles. The reactor can be divided into six axial zones based on the distinct flow patterns, fluidized bed dense-phase zone, the riser sparse-phase zone, riser concentration recover zone, riser accelerating zone, riser fully developed zone and riser back-mixing zone. The averaged cross-sectional density in the coupled reactor increases with the increase of particle mass flow rate and decreases with the increase of superficial gas velocity. Furthermore, empirical equations for estimating the axial distributions of averaged cross-sectional solids volume fraction are established based on the experimental data and theoretical analysis. The model predictions are in good agreement with the experimental data.

Key words: fluidized bed, riser, coupled reactor, asphalt particle, averaged cross-sectional density, flow behavior