Internal Optimization for Enhancing the Microbubble Dispersion Characteristics of a Stirred Tank
Xiangyang Li, Yongguang Duan, Haoliang Wang, Jingcai Cheng, Chao Yang
Abstract
Little research on the microbubble-aided transport characteristics in stirred vessels is reported. This motivates the present efforts to experimentally analyze the effects of operating condition, impeller, baffle, and sparger on the gas dispersion characteristics in a stirred tank with microbubble aeration. It is found that the number of large bubbles gradually increases with the increase of impeller speed, which is completely opposite of the results in the conventional gas–liquid stirred tank. Without baffles installed, kLa is greater than that in baffled ones, especially at the higher impeller speed. Under the same Pv, the impeller type has little effect on kLa. The ring sparger shows more efficient gas–liquid mass transfer performance than a single tube distributor. Under the combination of an axial impeller and a draft tube without baffles installed, the maximal kLa exceeds 0.01 s–1. The present study provides a useful reference for the design of stirred reactors in some applications.