摘要
在直径为φ260mm 的循环流化床中,采用工业 FCC(Y—7)催化剂,于气速1.45～4.71m/s 范围内测量了颗粒循环速率及循环床沿轴向的压力分布。根据轴向压力分布的分段特性,确定了循环床底部加速段的长度。引入了粒子团聚度系数 C 的概念,用所提出的模型对加速段内颗粒的加速规律进行了模拟计算。计算结果与实验数据吻合较好,并得出最合适的 C_(z)关系式为:C_(z)=C_(n)exp(-bZ)
In a circulating fluidized bed of 244 mm i.d.with FCC(Y7)catalyst as the solid particles,the particle circulating rate and pressure profile along the axis of the bed were measured in a range of su- Perficial gas velocity of 1.45-4.71ms,Based on the differences in pressure profiles along the axis, the bed can be seetionalized into three zones:particle accelerating zone,flow developing zone and sta- tionatry zone.The height of the accelerating zone plays an special important role in the performance of the whole bed and is dependent on gas velocity,particle circulating rate and the characteristics of the fluidized particles. Beause of the of the presence of and intense mixing between the large amounts of clusters formed by agglomeration of particles,solid particles bocome much more difficult to be accelerated than in the spertated of single particales.By introducing a clustering coefficient C,we found that the perfor. mance of the accelerating zone of a circulating fluidized bed can be well correlated and the relevant form of C obtained is C_1=C_1exp(—bZ)
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
1990年第2期29-36,共8页
Chemical Reaction Engineering and Technology
关键词
循环流化床
流化床
加速段
粒子团
Circulating fluidized bed
Accelerating zone
Particle clusters
Clustering coefficient
