三相外环流反应器的液相返混特性和气液传质特性  

LIQUID BACKMIXING CHARACTERISTICS AND GAS-LIQUID MASS TRANSFER COEFFICIENT OF THREE PHASE EXTERNAL-AIRLIFT LOOP REACTOR

作　　者：王焕君 费黎明[2] 陈定旺[2] 吕德伟[2] 

机构地区：[1]绍兴市标准计量局,312000 [2]浙江大学化工系,杭州310027

出　　处：《化学反应工程与工艺》1992年第2期178-184,共7页Chemical Reaction Engineering and Technology

摘　　要：主要研究了气速与固相对三相外环流反应器液相返混特性和气液传质特性的影响规律,并用“组合模型”分析了反应器各局部区域的返混情况。实验结果表明:液相返混主要由循环返混所致,约占95%以上;固相的存在对液相返混特性和气液传质特性均有显著的影响。研究结果对开发这类反应器具有重要意义。Liquid backmixing characteristics and gas-liquid mass transfer coefficient were investigated in a three phase external-airlift loop reactor with d_T=0.05 m.An axial dispersion model was used to describe the overall liquid backmixing characteristics and the empirical correlation of Bo number was obtained as Bo=10.9480Fr_g^(0.2850)(d_p/d_r)^(0.1758)(ρ_p/ρ_l)^(0.2664)exp(2.8084ε_s-3.7310Fr_l) with the correlation coefficient R=0.97 and mean deviation η=2.29% A combined model was built up and was used to analyse the liquid backmixing in the riser and the downcomer.The result revealed that the liquid backmixing is mainly caused by loop backmixing and the variance fraction in the downcomer is over 95%.The experimental results indicated that the solid holdup has significant effect on gas-liquid mass transfer coefficient.The empirical correlations of k_Lα was obtained as follows: k_Lα=1.2653u_g^(0.8158)exp(-8.004ε_s) or k_Lα=1.2256u_g^(0.8141)(1-ε_s)^(0.7322) with the same correlation coefficient R=0.984 and mean deviation η=6.5%.

关 键 词：返混 气液传质 反应器 外环流 

分 类 号：TQ052.01[化学工程]