无序环流混合器的流体力学特性和颗粒混合特性

发布时间：2018-03-31 19:30

本文选题：环流混合器　切入点：床层密度　出处：《化学反应工程与工艺》2017年02期

【摘要】：在内径为Φ286 mm的无序环流混合器装置中,研究了无序环流混合器的流体力学特性和颗粒混合特性。以催化裂化(FCC)平衡剂为颗粒相,在中心区表观气速为0.3~0.5 m/s,边壁区表观气速为0.1 m/s,系统循环强度为0.25~1.00 kg/s的操作条件下,采用PV-6D型颗粒速度密度测量仪测量了混合器内床层各截面密度,并给出不同操作条件下的截面不均匀指数(RNI);采用热颗粒示踪技术给出了混合器内各测量截面的无因次温度分布,并引入混合指数用来定量描述不同操作条件下的颗粒混合程度,同时对比了传统环流混合器与无序环流混合器的混合能力。结果表明,无序环流混合器内部床层密度呈现中心低,边壁高的分布模式。随着循环强度的增加,RNI先减小后增大,随着表观气速的增加,RNI增大。预混合区混合指数为0.7~0.9,在高循环量,低中心区表观气速条件下(G_s为1.00 kg/s,u_(gd)为0.3 m/s),下料管进料影响区的截面混合指数低于其他操作条件。另外,无序环流混合器混合能力优于传统环流混合器。
[Abstract]:The hydrodynamic and particle mixing characteristics of disordered circulation mixer with diameter of 桅 286 mm were studied. The equilibrium agent of FCCs was used as particle phase. Under the operating conditions that the apparent gas velocity in the central region is 0.3g / s, the apparent gas velocity in the side wall is 0.1 Ms / s, and the circulation intensity of the system is 0.25 ~ 1.00 kg/s, the cross section density of each bed in the mixer is measured by using the PV-6D particle velocity density meter. The cross section inhomogeneity index (RNI) under different operating conditions is given, and the dimensionless temperature distribution of the measured sections in the mixer is obtained by using thermal particle tracing technique, and the mixing index is introduced to quantitatively describe the degree of particle mixing under different operating conditions. At the same time, the mixing ability of conventional circulation mixer and disordered circulation mixer is compared. The results show that the inner bed density of disorder circulation mixer shows a distribution pattern of low center and high edge wall. With the increase of cycle intensity, RNI decreases first and then increases. With the increase of the apparent gas velocity, the mixing index of the premixed zone is 0. 7 ~ 0. 9. Under the condition of high circulation and low apparent gas velocity in the central region, the number of Gs is 1. 00 kg / s / s / d) = 0. 3 m / s / s, and the cross section mixing index of the affected area is lower than that of other operating conditions. The mixing ability of disorder circulation mixer is better than that of traditional circulation mixer.
【作者单位】：中国石油大学(北京)重质油国家重点实验室;
【基金】：国家重大基础研究计划(973)项目(2012CB215000)
【分类号】：TQ051.71

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