论文部分内容阅读
针对油砂直接流化焦化工艺,建立了一套大型冷模提升管循环流化床装置.粒度测试结果表明,该脱油油砂颗粒属宽筛分混合颗粒,且细颗粒含量较多,粒度分布宽(1~>2000 m).在不同操作条件下,采用多点压力密度测量仪测定了提升管内压力梯度和截面平均固含率沿提升管轴向的分布.实验结果表明,脱油油砂颗粒在提升管内截面的平均固含率随表观气速增大而减小,随颗粒循环强度增大而增大;固含率沿提升管轴向的分布为C型,即上下两端较浓、中间较稀,且沿提升管自上而下分为3个区域:颗粒约束返混区(>12 m)、充分发展区(4~12 m)和颗粒加速区(4m);在相同操作条件下,脱油油砂颗粒在提升管内截面的平均固含率高于FCC颗粒,加速段与约束返混段长度大于FCC颗粒;确定了脱油油砂颗粒在提升管内截面平均固含率的影响参数为εp’,Fr及Hr/Dr;通过实验数据回归得到提升管内截面平均固含率轴向分布的经验模型,计算与实验值吻合较好.
Aiming at the direct fluidized coking process of oil sands, a set of large-scale cold model riser circulating fluidized bed device was established.The results of particle size test showed that the de-oiled sands particles are of wide-screen mixed particles with more fine particles, (1 ~> 2000 m) .According to the different operating conditions, the multi-point pressure density meter was used to measure the pressure gradient in the riser and the distribution of the average solid content of the cross section in the axial direction of the riser.The experimental results show that the deoiled oil The average solid content of sand particles in the riser decreases with the increase of apparent gas velocity and increases with the increase of the cyclic strength of the sand particles. The distribution of solid content along the riser is C-shaped, that is, the upper and lower ends It is thicker with the middle being thinner and divided into three regions from top to bottom along the riser: particle confinement back-mixing zone (> 12 m), fully developed zone (4 ~ 12 m) and particle acceleration zone (4 m) Under the same operating conditions, the average solids content of the de-oiled sands particles in the riser is higher than that of the FCC particles, and the length of the accelerating segment and the constrained back-mixing segment is larger than that of the FCC particles. The average solids content of the de-oiled sands particles in the riser is determined The rate of influence parameters εp ’, Fr and Hr / Dr; through experimental data regression to enhance the tube cross-section Solid holdup empirical model are axially distributed, in good agreement with the experimental values is calculated.