半间歇式沸腾床反应器中液相循环速度的测定  

Liquid Circulation Velocity Measurements in a Semi-Batch Ebullated-Bed Reactor

作　　者：王伟伟 张建鹏 岳志[1] 黄子宾[1] 程振民[1] WANG Weiwei;ZHANG Jianpeng;YUE Zhi;HUANG Zibin;CHENG Zhenmin(State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2023年第2期161-167,共7页Journal of East China University of Science and Technology

基　　金：国家重点研发计划资助课题(2019YFC1906705)。

摘　　要：采用内径286 mm、高7.2 m的气-液-固三相沸腾床反应器进行了液相间歇、气相连续的操作研究,以水、空气、Al_(2)O_(3)球形颗粒构成三相体系,在固含率(体积分数)12%~30%和表观气速0.086~0.216 m/s下对宏观液相循环速度进行了测定。采用示踪剂法测定反应器进出口的多组示踪剂浓度曲线,使用MATLAB软件对液相轴向扩散系数进行求解,再代入爱因斯坦扩散系数定义式得到液相循环速度。实验结果表明,随着表观气速增大,液相循环速度相应增大;在固含率低于30%时,随着固含率增加,液相循环速度相应增加;但随着固含率进一步增大,液相循环速度的增幅越来越小。A gas-liquid-solid three-phase ebullated-bed reactor with an inner diameter of 286 mm and a height of 7.2 m was used to conduct intermittent liquid phase and continuous gas phase operations.The three-phase system was composed of water,air and Al_(2)O_(3) spherical particles.The macroscopic liquid circulation velocity was measured at a solid holdup of 12%~30%with a superficial gas velocity of 0.086~0.216 m/s.In this study,the tracer method was used to determine the concentration curves of multiple tracers at the inlet and outlet of the reactor.The axial dispersion coefficient of the liquid phase was solved by MATLAB software.Substituting it into the definition of Einstein's diffusion coefficient produced the liquid circulation velocity.The experimental results show that at a certain solid holdup,as the superficial gas velocity increases,small bubbles gradually gather into large bubbles.The rising velocity of the bubbles continues to increase,and the liquid circulation velocity also increases accordingly.Increasing the superficial gas velocity significantly increases the liquid circulation velocity.At a constant superficial gas velocity,as the solid holdup increases,both the large bubble holdup and the bubble rise velocity increase.This subsequently causes the liquid circulation velocity to increase.However,because the increase of solid holdup hinders the circulation of liquid to a certain extent,as the solid holdup increases,the increase rate of the liquid circulation velocity continues to decline.It is suggested that an optimal value for the solid holdup exists.

关 键 词：沸腾床反应器 液相循环速度 轴向扩散 固含率 示踪剂法 

分 类 号：TQ021.1[化学工程]