Bubble Sizes and Coalescence Rates in an Aerated Vessel Agitated by a Rushton Turbine

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Alvin W. Nienow¹  Koji Takahashi¹ 

[1] School of Chemical Engineering, The University of Birmingham

关键词: Agitation;    Bubble Size Distribution;    Rushton Turbine;    Gas-Liquid Mixing;    Gas Holdup;    Interfacial Area;    Sauter Mean Diameter;    Bubble Coalescence Rate;   

DOI  :  10.1252/jcej.26.536

来源: Maruzen Company Ltd

【 摘 要 】

References(12)Cited-By(26)For an improved understanding of gas-liquid mass transfer in a stirred-tank reactor and its spatial variation, knowledge of local bubble sizes (mean and distribution), gas holdups and coalescence rate is very important.In this work, bubble sizes at eight positions in an aerated vessel agitated by a 6-blade Rushton turbine were measured for an air-deionized water system by using flash photography. Bubble sizes near the vessel wall (and especially near the baffles) or in the upper levels of the vessel were more than four times those in the impeller region, The number of bubbles was also counted in a given area, and the population density was determined knowing the depth of focus.The coalescence rate during passage of the bubbles from the impeller to the vessel wall was calculated for different gases and liquids by measuring bubble sizes on photographs taken across the annular plane. It was found that coalescence occurs very near the impeller. The calculated values of coalescence rate were almost the same as those reported earlier by other investigators.

【 授权许可】

Unknown