新型搅拌桨用于黄原胶溶液气液传质的计算流体力学模拟

Computational fluid dynamics simulation of gas-liquid mass transfer in xanthan gum solution by novel impeller

采用计算流体力学(CFD)方法对高黏度非牛顿流体黄原胶水溶液(质量分数2%)中对称锯齿双斜叶涡轮搅拌桨(SPT)的搅拌效果进行模拟,并与传统的圆盘涡轮搅拌桨(DT)进行对比。通过多重参考系方法解决搅拌桨区域的运动问题,采用Eulerian-Eulerian模型模拟气液二相流动,气泡聚并和破裂过程通过群落平衡方程计算。结果发现,在高黏度体系中SPT气液传质混合性能优于DT。与DT相比,在考察的转速和表观气速下,SPT搅拌功率消耗降低35%左右,氧传质效率提高超过24%。

The gas dispersion generated by a symmetric sawtooth dual pitched blade disk turbine（SPT） in the mixing of xanthan gum solution with mass fraction of 2%,a high viscosity non-Newtonian fluid,was simulated by using a commercial computational fluid dynamics（CFD） technology.The simulated results were compared with the traditional disk turbine（DT）.The impeller was described in three dimensions with the multiple reference frame model.The dispersed gas in the turbulent flow was modeled by Eulerian-Eulerian approach.A series of population balance equations were implemented to account for the combined effect of bubble breakup and coalescence in the tank.It shows that the gas-liquid mass transfer and mixing performance of SPT are better than those of DT.As compared with DT,SPT can reduce power consumption by 35%,and increase oxygen transfer efficiency by more than 24%.