流化床-提升管耦合反应器内沥青颗粒的流动特性

针对重油残渣(沥青颗粒)气化制氢工艺，在流化床-提升管耦合反应器大型冷模实验装置上，考察了不同操作条件下沥青颗粒体系在耦合反应器内截面平均密度的轴向分布. 结果表明，对单组分沥青颗粒体系，耦合反应器适宜的操作条件为：提升管表观气速ug,r=0.70~1.76 m/s；与A类颗粒相比，沥青颗粒在耦合反应器内的流动特性呈现不同的特点，整个反应器沿轴向可分为底部流化床密相区、提升管底部低密度区、提升管颗粒密度重整区、提升管加速区、充分发展区和出口约束区6个区域；反应器内截面平均密度随颗粒质量流率增大而增大，随表观气速增大而减小；确定了耦合反应器内提升管区域截面平均固含率的影响参数为ep', Fr及H/Dr，并利用实验数据回归了平均固含率的轴向分布经验模型，其计算值与实验值吻合较好.

Flow Behavior of Asphalt Particles in a Fluidized Bed-Riser Coupled Reactor

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.