Mass Transfer Characteristics by Surface Aeration of Large Paddle Impeller: Application to a Polymerization Reactor with Liquid Level Change

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Katsuhide Takenaka²  Koji Takahashi³  Philippe A. Tanguy¹  Ryuichi Yatomi² 

[1] URPEI, Department of Chemical Engineering, Ecole Polytechnique;SHI Mechanical & Equipment INC. (Sumitomo Heavy Industries Group);Department of Chemistry and Chemical Engineering, Yamagata University

关键词: Large Paddle Impeller;    Surface Aeration;    kLa;    Liquid Level Change;    Hydrogenation;    Alkoxylation;   

DOI  :  10.1252/jcej.40.393

来源: Maruzen Company Ltd

【 摘 要 】

References(7)Cited-By(1)The aim of this study is to investigate the mass-transfer characteristics of a large paddle impeller by comparing with those of the down-pumping pitched blade turbine and the Rushton turbine, and also to probe the application of surface aeration to batch hydrogenation in polymerization processes and the ethylene oxide additional reaction. Laboratory and industrial data were used for this purpose. As a result, it has been found that, with the large paddle impeller, large kLa values of surface aeration without sparging can be obtained continuously at any liquid level because of the combined effect of surface breakage, bubble entrapment and efficient liquid circulation by axial pumping capacity of the impeller. Using these experimental kLaV data, the improvement in the operation time for a 12 m3 alkoxylation reactor was estimated. The reactor was then retrofitted with a large paddle impeller, and the actual operation time of 17 h was found to be strictly identical to the estimation, that is 75% reduction of the usual 70 h. This result shows the advantage of large paddle impellers in industrial processes and the accuracy of the estimation procedure.

【 授权许可】

Unknown