超声波气升式内环流反应器传质性能的实验研究

Experimental Study of Mass Transfer Characteristics in Ultrasonic Airlift Reactor

研究了超声波对气升式内循环反应器传质性能的促进作用,重点考察比较了牛顿型流体和非牛顿型流体 有、无超声波时气升式反应器的传质性能及气速、液体粘度、超声功率对总体积传质系数KLa的影响。实验证明， 无论是牛顿型流体还是非牛顿型流体，气速越小，超声功率对总体积传质系数KLa的相对影响越大；随着气速的 增大，这种影响逐渐减小，当气速增大到0.0615m·s-1时，超声波对总体积传质系数KLa的相对影响已较微弱。气 速增加，牛顿型流体和非牛顿型流体的KLa均增加，但牛顿型流体增加的幅度比非牛顿型流体要大。粘度增加，KLa 减小。气速、粘度、超声功率对KLa的影响分别是气速大于粘度大于超声功率。提出了相应的KLa经验关联式，并作了 讨论。

The volumetric mass transfer coefficients of the airlift internal loop reactor were intensified by ultrasound. Mass transfer characteristics were observed and compared for Newtonian liquid and non-Newtonian liquid with or without ultrasound. Mass transfer coefficient KLa was influenced by super-facial gas velocity, liquid viscosity and ultrasonic power. It had been found that, in Newtonian liquid and non-Newtonian liquid, the smaller the gas velocity is, the bigger the relative effect of ultrasound on volumetric mass transfer coefficient KLa is. When gas velocity increases, the effect decreases gradually. When the gas velocity increases to 0.0615 m&middots-1, the relative effect of ultrasound on volumetric mass transfer coefficient is rather minor. When gas velocity increases, the KLa of Newtonian liquid and non-Newtonian liquid both increase, but the increased extent of Newtonian liquid is larger than that of non-Newtonian liquid. When viscosity increases, KLa decreases. The effects of gas velocity, viscosity, and ultrasonic power on KLa are as follows: gas velocity larger than viscosity larger than ultrasonic power. Furthermore, the corresponding KLa correlations were proposed and discussed.