环隙气升式生物反应器三维CFD建模与仿真

CFD Modeling and Simulation of an Annulus Sparged Air-lift Bioreactor

气升式生物反应器被广泛地用于低耗氧微生物发酵过程中,如维生素C的发酵生产。采用计算流体力学对一个缩小的、工业环隙气升式生物反应器内的流体流动进行了建模与仿真,寻找该反应器内流体流动状态的规律。结果表明,在通气量比较小的情况下,生物反应器内的流体流动是极为复杂的,气含率分布和液体速度分布都存在着很大的不均匀性。但通过三维CFD仿真可以近似地确定流态接近CSTR和PFR的区域,从而为简化的CSTR-PFR组合流动模型的建模提供依据。

Air-lift bioreactors(ABR) are widely used in the low oxygen and microorganism fermentation industry such as the L-ascorbic acid production.CFD modeling and simulations for an annulus sparged ABR are carried out to portray the flow characteristics,which is a scaled geometry of an industrial annulus sparged ABR for L-ascorbic acid production.The results show the flow behavior of the liquid phase in the ABR is very complicated at a lower gas flow rate,the profiles of gas holdup and liquid velocity are quite un-uniform.With three-dimensional simulations the regions for the CSTR and the PFR could be determined approximately,which provides the foundation for simplifying the combined model of CSTR-PFR.