Influence of impeller diameter on overall gas dispersion properties in a sparged multi-impeller stirred tank  

桨径变化对多层桨通气搅拌槽内气液分散宏观特性的影响（英文）

作　　者：包雨云 王冰洁 林明丽 高正明 杨杰 

机构地区：[1]State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology

出　　处：《Chinese Journal of Chemical Engineering》2015年第6期890-896,共7页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(21121064,21206002,21376016)

摘　　要：The impeller configuration with a six parabolic blade disk turbine below two down-pumping hydrofoil propellers, identified as PDT + 2CBY, was used in this study. The effect of the impeller diameter D, ranging from0.30 T to 0.40T(T as the tank diameter), on gas dispersion in a stirred tank of 0.48 m diameter was investigated by experimental and CFD simulation methods. Power consumption and total gas holdup were measured for the same impeller configuration PDT + 2CBY with four different D/T. Results show that with D/T increases from 0.30 to 0.40, the relative power demand(RPD) in a gas–liquid system decreases slightly. At low superficial gas velocity VSof 0.0078 m·s-1, the gas holdup increases evidently with the increase of D/T. However, at high superficial gas velocity, the system with D/T = 0.33 gets a good balance between the gas recirculation and liquid shearing rate, which resulted in the highest gas holdup among four different D/T. CFD simulation based on the two-fluid model along with the Population Balance Model(PBM) was used to investigate the effect of impeller diameter on the gas dispersion. The power consumption and total gas holdup predicted by CFD simulation were in reasonable agreement with the experimental data.The impeller configuration with a six parabolic blade disk turbine below two down-pumping hydrofoil propellers, identified as PDT ＋ 2CBY, was used in this study. The effect of the impeller diameter D, ranging from0.30 T to 0.40T（T as the tank diameter）, on gas dispersion in a stirred tank of 0.48 m diameter was investigated by experimental and CFD simulation methods. Power consumption and total gas holdup were measured for the same impeller configuration PDT ＋ 2CBY with four different D/T. Results show that with D/T increases from 0.30 to 0.40, the relative power demand（RPD） in a gas–liquid system decreases slightly. At low superficial gas velocity VSof 0.0078 m·s-1, the gas holdup increases evidently with the increase of D/T. However, at high superficial gas velocity, the system with D/T = 0.33 gets a good balance between the gas recirculation and liquid shearing rate, which resulted in the highest gas holdup among four different D/T. CFD simulation based on the two-fluid model along with the Population Balance Model（PBM） was used to investigate the effect of impeller diameter on the gas dispersion. The power consumption and total gas holdup predicted by CFD simulation were in reasonable agreement with the experimental data.

关 键 词：Gas holdup MIXING Multiphase reactors Relative power demand CFD Multi-impeller stirred tank 

分 类 号：TQ051.72[化学工程]