化工学报 ›› 2010, Vol. 61 ›› Issue (9): 2208-2216.

• 流体力学与传递现象 • 上一篇    下一篇

喷嘴油气在提升管进料段的浓度径向分布及混合行为

鄂承林,蔡丹枫,范怡平,卢春喜,徐春明,时铭显   

  1. 中国石油大学(北京)重质油国家重点实验室
  • 出版日期:2010-09-05 发布日期:2010-09-05

Concentration distribution and mixing process of jet gas in feed injection zone of FCC riser

E Chenglin,CAI Danfeng,FAN Yiping,LU Chunxi,XU Chunming, SHI Mingxian   

  • Online:2010-09-05 Published:2010-09-05

摘要:

φ200 mm提升管冷态实验装置上,根据喷嘴油气在进料段4个轴向位置(H=0.375、0.675、1.075、1.375 m)及不同操作参数(Ur=2.25~4.30 m·s-1Uj=41.7~62.5 m·s-1Mj/Mr=0.29~4.21)的浓度径向分布形式,考察了喷嘴油气与预提升气体和颗粒在进料段内的混合过程。结果表明,喷嘴油气在进料段内存在6种浓度径向分布形式,反映了喷嘴油气与预提升气体和颗粒在进料段的不同混合行为,沿轴向由下至上分别为:未混合区(强M形分布)、混合区(弱M形分布、强三峰形分布、弱三峰形分布、单峰形分布)及完成混合区(环-核分布)。随着Uj的增加或Ur的减小,喷嘴油气与预提升气体和颗粒在进料段内的未混合区、混合区及完成混合区的轴向高度逐渐增加。采用喷嘴射流动量与预提升来流动量之比Mj/Mr考察了操作参数及装置结构尺寸等对喷嘴油气与预提升气体和颗粒在进料段内混合过程的综合影响。喷嘴油气与预提升气体和颗粒的未混合区、混合区及完成混合区的轴向位置在动量比Mj/Mr≤0.29时分别为:0~0.375 m、0.375~0.525 m、0.525~0.675 m;在动量比Mj/Mr=0.29~0.54时分别为:0~0.375 m、0.375~0.875 m、0.875~1.075 m;在动量比Mj/Mr=0.54~4.21时分别为:0~0.525 m、0.525~1.225 m、1.225~1.375 m。

关键词: 提升管, 进料段, 油气浓度, 混合过程

Abstract:

The concentration profiles of jet gas are investigated in the feed injection zone of a cold-model FCC riser by using a hydrogen trace technique.Experimental results demonstrate that six types of jet gas concentration profiles can be used to describe the mixing process of the jet gas with pre-lift gas and catalyst particles in the feed injection zone.The six types are a distinct M-shaped profile for no mixing region,an indistinct M-shaped profile,a distinct three-peak profile,an indistinct three-peak profile and an one-peak profile for mixing region,and a annular-core profile for full mixing region.The heights for regions of initial and full mixing reduce when decreasing the jet gas velocity or increasing the pre-lift gas velocity. Furthermore,the momentum ratio,Mj/Mr,is introduced to describe effects of gas-solid physical properties,operating conditions,and equipment configuration on the jet gas concentration distribution.The heights for regions of no mixing,mixing and full mixing between jet gas with pre-lift gas and catalyst particles are found to be 0—0.375 m,0.375—0.525 m and 0.525—0.675 m when Mj/Mr≤0.29,0—0.525 m,0.525—1.225 m and 1.225—1.375 m when Mj/Mr>0.54,and 0—0.375 m,0.375—0.875 m and 0.875—1.075 m when Mj/Mr between 0.29 and 0.54,respectively.

Key words: 提升管, 进料段, 油气浓度, 混合过程