Liquid Flow Characteristics inside Impeller Rotational Region of an Unbaffled Vessel Agitated with an Unsteadily Angularly Oscillating Impeller  

作　　者：Masanori Yoshida Keisuke Mikazuki Kazuaki Yamagiwa Shuichi Tezura 

机构地区：[1]Department of Chemistry and Chemical Engineering, Niigata University, Niigata 950-2181, Japan [2]Shimazaki Mixing Equipment Co., Ltd., Tokyo 116-0014, Japan

出　　处：《Journal of Chemistry and Chemical Engineering》2011年第4期348-354,共7页化学与化工（英文版）

摘　　要：Characteristics of the liquid flow were studied in the impeller region for an unbaffied vessel agitated with an angularly oscillating impeller whose rotation proceeds while periodically reversing its direction at the set angle, namely, rotating unsteadily with sinusoidal variation of the set amplitude. Measurement of the velocity of the liquid flow was performed, abreast of that of the torque of the shaft attached with the impeller. A disk turbine impeller with six flat blades was used in angular oscillation mode at the different amplitudes. The power characteristics were analyzed with the power number during one cycle of the angular oscillation consisting of a process for the impeller to stop and to reverse and that to rotate with a certain acceleration-deceleration in a uniform orientation. The power number in the process for the impeller to rotate exhibited slightly lower values compared with that of the identical design of impeller used in unidirectional rotation mode in a fully baffled vessel, being higher values in its process to stop and to reverse. Under such an operating condition in the amplitude, a time series of images was analyzed by particle tracking velocimetry （PTV） to characterize the fluctuation components of the velocities of the circumferential and radial flows inside the impeller rotational region. The impeller in its rotation process produced flows having a relatively large turbulence, independent of the amplitude condition. For the radial flow relating to the discharge flow, which contributes to transport of the turbulence throughout the vessel, operation at higher amplitude was clarified to be successful.

关 键 词：Unbaffled agitated vessel unsteadily rotating impeller angular oscillation liquid flow impeller power 

分 类 号：TQ051.13[化学工程] TM712[电气工程—电力系统及自动化]